diff --git a/.dockerignore b/.dockerignore new file mode 100644 index 00000000..f5e8e83a --- /dev/null +++ b/.dockerignore @@ -0,0 +1,4 @@ +.github +documents +docker/Dockerfile +docker/classic/Dockerfile \ No newline at end of file diff --git a/.github/FUNDING.yml b/.github/FUNDING.yml index b7d5ff89..41d81e74 100644 --- a/.github/FUNDING.yml +++ b/.github/FUNDING.yml @@ -1 +1 @@ -custom: [paypal.me/UMBr] +custom: [paypal.me/UMBr] \ No newline at end of file diff --git a/.github/ISSUE_TEMPLATE/Bug Report.yaml b/.github/ISSUE_TEMPLATE/Bug Report.yaml index e9936a39..9461f606 100644 --- a/.github/ISSUE_TEMPLATE/Bug Report.yaml +++ b/.github/ISSUE_TEMPLATE/Bug Report.yaml @@ -1,12 +1,23 @@ +<<<<<<< HEAD name: Issue Report description: File an Issue title: "[Problem]: " labels: ["new issue"] +======= +name: Bug Report +description: File a bug report +title: "[Bug]: " +labels: ["bug"] +>>>>>>> origin/development body: - type: markdown attributes: value: | +<<<<<<< HEAD Thanks for taking the time to fill out this report! +======= + Thanks for taking the time to fill out this bug report! +>>>>>>> origin/development - type: textarea id: what-happened attributes: @@ -21,6 +32,7 @@ body: description: Please copy and paste any relevant log output. This will be automatically formatted into code, so no need for backticks. render: shell - type: textarea +<<<<<<< HEAD id: os attributes: label: Operating System? @@ -28,12 +40,15 @@ body: validations: required: true - type: textarea +======= +>>>>>>> origin/development id: version attributes: label: Version? description: What version of Shairport Sync are you running? (`shairport-sync -V`) validations: required: true +<<<<<<< HEAD - type: dropdown id: install attributes: @@ -45,6 +60,8 @@ body: - Built from source validations: required: true +======= +>>>>>>> origin/development - type: checkboxes id: checked-current-issues attributes: @@ -52,4 +69,8 @@ body: description: Please check previous issues (including closed ones) for duplicates. options: - label: Confirm +<<<<<<< HEAD required: true +======= + required: true +>>>>>>> origin/development diff --git a/.github/workflows/docker-build-on-push.yaml b/.github/workflows/docker-build-on-push.yaml index 3ae6ed5b..02017eb5 100644 --- a/.github/workflows/docker-build-on-push.yaml +++ b/.github/workflows/docker-build-on-push.yaml @@ -1,5 +1,5 @@ -# Builds & pushes a docker image when a commit is made to one of the branches specified below. -# Tag pattern: 'unstable-[BRANCH NAME]'. +# Builds & pushes a docker image when a commit is made to one of the branches specified below. +# Tag pattern: 'unstable-[BRANCH NAME]' & 'unstable-[BRANCH NAME]-classic' name: Build and push docker image based on commit to specified branches. @@ -22,6 +22,14 @@ jobs: - name: Set SHAIRPORT_SYNC_BRANCH env. run: echo "SHAIRPORT_SYNC_BRANCH=${GITHUB_REF##*/}" >> $GITHUB_ENV + - name: Determine NQPTP env (part 1). + if: ${{ env.SHAIRPORT_SYNC_BRANCH == 'development' }} + run: echo "NQPTP_BRANCH=development" >> $GITHUB_ENV + + - name: Determine NQPTP env (part 2). + if: ${{ env.SHAIRPORT_SYNC_BRANCH != 'development' }} + run: echo "NQPTP_BRANCH=main" >> $GITHUB_ENV + - name: Set up QEMU uses: docker/setup-qemu-action@v1 @@ -35,13 +43,33 @@ jobs: username: ${{ secrets.DOCKER_REGISTRY_USER }} password: ${{ secrets.DOCKER_REGISTRY_TOKEN }} + - name: Set tag start (part 1). + if: ${{ env.SHAIRPORT_SYNC_BRANCH == 'master' }} + run: echo "IMAGE_TAG_BASE=unstable" >> $GITHUB_ENV + + - name: Set tag start (part 2). + if: ${{ env.SHAIRPORT_SYNC_BRANCH != 'master' }} + run: echo "IMAGE_TAG_BASE=unstable-${{ env.SHAIRPORT_SYNC_BRANCH }}" >> $GITHUB_ENV + - name: Build and push uses: docker/build-push-action@v2 with: context: ./ - file: ./docker/airplay1/Dockerfile + file: ./docker/Dockerfile platforms: ${{ env.DOCKER_PLATFORMS }} push: true - tags: ${{ secrets.DOCKER_IMAGE_NAME }}:unstable-${{ env.SHAIRPORT_SYNC_BRANCH }} + tags: ${{ secrets.DOCKER_IMAGE_NAME }}:${{ env.IMAGE_TAG_BASE }} + build-args: | + SHAIRPORT_SYNC_BRANCH=${{ env.SHAIRPORT_SYNC_BRANCH }} + NQPTP_BRANCH=${{ env.NQPTP_BRANCH }} + + - name: Build and push (AirPlay 1) + uses: docker/build-push-action@v2 + with: + context: ./ + file: ./docker/classic/Dockerfile + platforms: ${{ env.DOCKER_PLATFORMS }} + push: true + tags: ${{ secrets.DOCKER_IMAGE_NAME }}:${{ env.IMAGE_TAG_BASE }}-classic build-args: | SHAIRPORT_SYNC_BRANCH=${{ env.SHAIRPORT_SYNC_BRANCH }} \ No newline at end of file diff --git a/.github/workflows/docker-build-on-tag.yaml b/.github/workflows/docker-build-on-tag.yaml index 96e893f8..6762a9bd 100644 --- a/.github/workflows/docker-build-on-tag.yaml +++ b/.github/workflows/docker-build-on-tag.yaml @@ -1,8 +1,8 @@ # Builds & pushes a docker image when a tag occurs. # It seems this yaml has to exist on the branch the tag refers to. -# The following tags are created & pushed: -# [RELEASE TAG] and latest +# The following docker tags are created & pushed: +# [RELEASE TAG], [RELEASE TAG]-classic, name: Build and push docker images on releases. @@ -31,6 +31,14 @@ jobs: - name: Set tag env run: echo "GIT_TAG=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV + + - name: Determine NQPTP env (part 1). + if: ${{ env.SHAIRPORT_SYNC_BRANCH == 'development' }} + run: echo "NQPTP_BRANCH=development" >> $GITHUB_ENV + + - name: Determine NQPTP env (part 2). + if: ${{ env.SHAIRPORT_SYNC_BRANCH != 'development' }} + run: echo "NQPTP_BRANCH=main" >> $GITHUB_ENV - name: Set up QEMU uses: docker/setup-qemu-action@v1 @@ -49,9 +57,21 @@ jobs: uses: docker/build-push-action@v2 with: context: ./ - file: ./docker/airplay1/Dockerfile + file: ./docker/Dockerfile platforms: ${{ env.DOCKER_PLATFORMS }} push: true - tags: ${{ secrets.DOCKER_IMAGE_NAME }}:latest, ${{ secrets.DOCKER_IMAGE_NAME }}:${{ env.GIT_TAG }} + tags: ${{ secrets.DOCKER_IMAGE_NAME }}:${{ env.GIT_TAG }} + build-args: | + SHAIRPORT_SYNC_BRANCH=${{ env.SHAIRPORT_SYNC_BRANCH }} + NQPTP_BRANCH=${{ env.NQPTP_BRANCH }} + + - name: Build and push (Classic) + uses: docker/build-push-action@v2 + with: + context: ./ + file: ./docker/classic/Dockerfile + platforms: ${{ env.DOCKER_PLATFORMS }} + push: true + tags: ${{ secrets.DOCKER_IMAGE_NAME }}:${{ env.GIT_TAG }}-classic build-args: | SHAIRPORT_SYNC_BRANCH=${{ env.SHAIRPORT_SYNC_BRANCH }} \ No newline at end of file diff --git a/.gitignore b/.gitignore index 9acdfd33..096527a9 100644 --- a/.gitignore +++ b/.gitignore @@ -5,7 +5,6 @@ /shairport-sync-mpris-test-client *.o -*.log /*~ *.xml~ /config.mk @@ -26,6 +25,7 @@ stamp-h1 man/Makefile man/Makefile.in scripts/shairport-sync.service +scripts/shairport-sync.service-avahi scripts/shairport-sync shairport-sync.core gitversion.h @@ -36,6 +36,7 @@ plist_xml_strings.* /org.gnome.ShairportSync.service /dbus-interface.* /mpris-interface.* +/plist_xml_strings.* /lib_*.* # Some eclipse project files @@ -46,4 +47,11 @@ plist_xml_strings.* .DS_Store shairport-sync.xcodeproj +# version string generation +gitversion.h +# separate build directory +build + +# vscode +.vscode diff --git a/.gitmodules b/.gitmodules new file mode 100644 index 00000000..e69de29b diff --git a/ADDINGTOHOME.md b/ADDINGTOHOME.md new file mode 100644 index 00000000..3d3ed5dc --- /dev/null +++ b/ADDINGTOHOME.md @@ -0,0 +1,29 @@ +Here is how to add a Shairport Sync device to the Apple Home application on iOS 15.3.1. Note that Shairport Sync has to be built with AirPlay 2 support. + +*** + +Step 1: Open the "Home" app +--- + +Tap the `Add Accessory` panel or choose "Add Accessory" from the `+` symbol in the top right: + +![IMG_3678](https://user-images.githubusercontent.com/4265913/157615721-e42a07e3-f93e-49d0-9233-e7b92a577459.jpg) + +*** + +Step 2: "More options..." +--- + +Step 2: Tap `More options...` + +![IMG_3679](https://user-images.githubusercontent.com/4265913/157616118-79c6d494-ce6e-4666-a6de-53cb40d0e751.jpg) + + +*** + +Step 3: Select your Shairport Sync device: +--- + +Your Shairport Sync device should appear here, though you may have to scroll. Tap the appropriate icon and follow the remaining instructions. + +![IMG_3680](https://user-images.githubusercontent.com/4265913/157616475-22ee2eb6-56f4-4368-a1ed-d925f9984f1e.jpg) diff --git a/ADVANCED TOPICS/Events.md b/ADVANCED TOPICS/Events.md new file mode 100644 index 00000000..0fd15ead --- /dev/null +++ b/ADVANCED TOPICS/Events.md @@ -0,0 +1,12 @@ +## Events +Shairport Sync can run programs just before it starts to play an audio stream and just after it finishes. +You specify them using the `sessioncontrol` group settings `run_this_before_play_begins` and `run_this_after_play_ends`. +This is to facilitate situations where something has to be done before and after playing, e.g. switching on an amplifier beforehand +and switching it off afterwards. +Set the `wait_for_completion` value to `"yes"` for Shairport Sync to wait until the respective commands have been completed before continuing. + +Note that the full path to the programs must be specified, and script files will not be executed unless they are marked as executable +and have the appropriate shebang `#!/bin/...` as the first line. (This behaviour may be different from other Shairports.) + +Shairport Sync can run a program whenever the volume is set or changed. You specify it using the `general` group setting `run_this_when_volume_changes`. +This is to facilitate situations where something has to be done when the volume changes, e.g. adjust an external mixer value. Set the `wait_for_completion` value to `"yes"` for Shairport Sync to wait until the command has been completed before continuing. Again, please note that the full path to the program must be specified, and script files will not be executed unless they are marked as executable and have the appropriate shebang `#!/bin/...` as the first line. diff --git a/ADVANCED TOPICS/GetTheBest.md b/ADVANCED TOPICS/GetTheBest.md new file mode 100644 index 00000000..cf07e19d --- /dev/null +++ b/ADVANCED TOPICS/GetTheBest.md @@ -0,0 +1,54 @@ +# Get The Best from Shairport Sync +Shairport Sync was designed to run best on dedicated stand-alone low-power "headless" Linux/FreeBSD systems with ALSA as the audio system +and with a decent CD-quality Digital to Analog Converter (DAC). + +## CPU Power and Memory +Computer power and memory requirements are modest -- a Raspberry Pi 2 or better, including the Pi Zero 2 W, is fine. +Unfortunately, while the original Raspberry Pi and the Pi Zero are powerful enough for AirPlay operation, +they are not really suitable for AirPlay 2 operation. + +## CPU Clock +For best performance, Shairport Sync requires a stable and accurate system clock. +This is because the output DAC's output rate is normally determined by the system clock (some high-end USB streamers use their own built-in clocks). +If the clock drifts, or if its actual frequency is far from its nominal frequency, Shairport Sync will have to do more interpolation, +which inevitably must degrade the audio fidelity, even if it is very hard to hear. +Some very old laptops are known to have inaccurate clocks and and some embedded systems can suffer from temperature-related clock drift. + +Recent Raspberry Pis seem to have very accurate clocks with low drift. + +## Linux +The best kind of Linux for Shairport Sync is a "bare" Linux. +Raspberry Pi OS Lite, Debian Minimal Server, Ubuntu Server, Fedora Server and Arch Linux (Minimal Configuration) are good examples. + +Shairport Sync also runs on "desktop" Linuxes such as Raspberry Pi OS with desktop, Debian with a desktop environment, +Ubuntu Desktop and Fedora Workstation. +Desktop Linuxes are less suitable because they almost always use a sound server like PulseAudio or PipeWire. +These can interfere with Shairport Sync, which needs direct and exclusive access to the audio hardware. + +## DAC +A good Digital to Analog Converter (DAC) will have a huge influence on the quality of the audio. + +Shairport Sync runs at 44,100 frames per second (FPS), each frame consisting of a pair of signed 16 bit linear samples, one for left and one for right. +Actually, Shairport Sync will take advantage to 24- or 32-bit DACs if available, and will run at 44,100 or 88,200, 176,400 or 352,800 FPS if necessary, +though there is no advantage to the higher rates. The 44,100 FPS rate was chosen to match the rate of AirPlay. + +Good DACs are available at a very wide range of prices, from low-cost USB "Sound Cards" to very high-end HiFi streaming DACs. + +In the Raspberry Pi world, many very good low-cost I2S DACs, some with integrated amplifiers, are available. Staying with the Raspberry Pi, the DAC powering the built-in audio jack is not great. It may be good enough for trying out Shairport Sync, but it has a very limited frequency response and can generate very large transients when it starts up. A separate DAC will transform the output quality. + +**Note** +Make sure that the DAC is capable of 44,100 FPS operation -- this is really mandatory. +Most recent DACs are okay, but some older DACs will only run at 48,000 FPS or multiples of it, and Shairport Sync can not use them. +## Maximum Output Level +The `volume_max_db` setting allows you to reduce the maximum level of DAC output to prevent possible overloading of the amplifier or premplifier it feeds. +## Volume Range +The volume range is the difference (technically the ratio, expressed in dB) between the highest and lowest level of the volume control. Ideally, this should give the highest volume at the high end and a barely audible sound at the lowest level. Typical volume ranges are 60 dB to 75dB. If the range is much less than this, the difference between high and low volume won't seem large enough to the listener. If the range is much more, much of the low end of the volume control range will be inaudible. (The built-in DAC of the Raspberry Pi has this problem.) Use the `volume_range_db` setting to set the volume range. The built-in attenuator will be used to augment the volume range if necessary. +## Volume Control +Audio is sent at full volume in AirPlay and AirPlay 2 with separate information being sent to set the actual volume. This volume information can be used in three ways: +* It can be used to control a built-in attenuator. This is the default. +* It can be used to control a mixer built in to the DAC. To use a mixer, set the `mixer_control_name` in the configuration file to the name of the mixer you wish to use. +* It can be ignored by Shairport Sync. This may be appropriate when you want the volume to be controlled by just one control, typically an audio system's volume control knob or the volume control of a car radio. To make Shairport Sync ignore the volume information, set `ignore_volume_control` to `"yes"`. +* AirPlay volume changes cause events when an executable -- a program or executable script -- can be called. So, you could get Shairport Sync to ignore volume control information but call an executable to control an external volume control. +## Other Settings +* The `disable_standby_mode` setting can be used to prevent the DAC from transitioning between active and standby states, which can sometimes cause a faint popping noise. If activated, Shairport Sync sends frames of silence to keep the DAC busy, preventing it from entering standby mode. +* The `disable_synchronisation` setting can be used to prevent Shairport Sync from doing any interpolation whatever. Normally, this would lead to a problem when the DAC's buffer either overflowed or underflowed, but some very high-end streamers adjust the rate at which their DACs run to match the exact rate at which audio arrives, thus preventing underflow or overflow. diff --git a/ADVANCED TOPICS/InitialConfiguration.md b/ADVANCED TOPICS/InitialConfiguration.md new file mode 100644 index 00000000..1e99e5ca --- /dev/null +++ b/ADVANCED TOPICS/InitialConfiguration.md @@ -0,0 +1,205 @@ +# Initial Configuration +Shairport Sync reads settings from a configuration file at `/etc/shairport-sync.conf` (note that in FreeBSD it will be at `/usr/local/etc/shairport-sync.conf`). When you run `$sudo make install`, a sample configuration file is installed or updated at `/etc/shairport-sync.conf.sample` (`/usr/local/etc/shairport-sync.conf.sample` in FreeBSD). This contains all the setting groups and all the settings available, but they all are commented out (comments begin with `//`) so that default values are used. The file contains explanations of the settings, useful hints and suggestions. In addition, if the file doesn't already exist, a default configuration is installed, which should work in almost any system with a sound card. + +Settings in the configuration file are grouped. For instance, there is a `general` group within which you can use the `name` tag to set the service name. Suppose you wanted to set the name of the service to `Front Room` and give the service the password `secret`, then you should do the following: + +``` +general = +{ + name = "Front Room"; + password = "secret"; + // ... other general settings +}; + +``` +The password setting is only valid for classic Shairport Sync. + +(Remember, anything preceded by `//` is a comment and will have no effect on the setting of Shairport Sync.) + +**Important:** You should *never* use an important password as the AirPlay password for a Shairport Sync player -- the password is stored in Shairport Sync's configuration file in plain text and is thus completely vulnerable. + +No backend is specified here, so it will default to the `alsa` backend if more than one back end has been compiled. To route the output to PulseAudio, add: +``` + output_backend = "pa"; +``` +to the `general` group. + +The `alsa` group is used to specify properties of the output device. The most obvious setting is the name of the output device which you can set using the `output_device` tag. + +The following `alsa` group settings are very important for maximum performance. If your audio device has a mixer that can be use to control the volume, then Shairport Sync can use it to give instant response to volume and mute commands and it can offload some work from the processor. +* The `mixer_control_name` tag allows you to specify the name of the mixer volume control. +* The `mixer_device` tag allows you specify where the mixer is. By default, the mixer is on the `output_device`, so you only need to use the `mixer_device` tag if the mixer is elsewhere. This can happen if you specify a *device* rather than a *card* with the `output_device` tag, because normally a mixer is associated with a *card* rather than a device. Suppose you wish to use the output device `5` of card `hw:0` and the mixer volume-control named `PCM`: + +``` +alsa = +{ + output_device = "hw:0,5"; + mixer_device = "hw:0"; + mixer_control_name = "PCM"; + // ... other alsa settings +}; +``` + +The `pa` group is used to specify settings relevant to the PulseAudio backend. You can set the "Application Name" that will appear in the "Sound" control panel. + +Note: Shairport Sync can take configuration settings from command line options. This is mainly for backward compatibility, but sometimes still useful. For normal use, it is strongly recommended that you use the configuration file method. + +**Raspberry Pi** + +The Raspberry Pi Models A and B have a built-in audio DAC that is connected to the device's headphone jack. Apart from a loud click when used for the first time after power-up, it is now quite adequate for casual listening. + +To get the benefits of improvements in the Pi's software and firmware, you should update to the Raspian release of October 2018 or later, as a number of improvements have been made to the built-in DAC. + +Do the usual update and upgrade: +``` +# apt update +# apt upgrade +``` +To make Shairport Sync output to the built-in audio DAC and use its hardware mixer, in the `alsa` section of the configuration file, set the output device and mixer as follows: +``` +alsa = +{ + output_device = "hw:0"; // the name of the alsa output device. Use "alsamixer" or "aplay" to find out the names of devices, mixers, etc. + mixer_control_name = "PCM"; // the name of the mixer to use to adjust output volume. If not specified, volume in adjusted in software. + // ... other alsa settings +``` +(Remember to uncomment the lines by removing the `//` at the start of each.) When these changes have been made, reboot the machine. + +A problem with the built-in DAC that it declares itself to have a very large mixer volume control range – all the way from -102.38dB up to +4dB, a range of 106.38 dB. In reality, only the top 60 dB of it is in any way usable. To help get the most from it, consider using the `volume_range_db` setting in the `general` group to instruct Shairport Sync to use the top of the DAC mixer's declared range. For example, if you set the `volume_range_db` figure to 60, the top 60 dB of the range will the used. With this setting on the Raspberry Pi, maximum volume will be +4dB and minimum volume will be -56dB, below which muting will occur. + +From a user's point of view, the effect of using this setting is to move the minimum usable volume all the way down to the bottom of the user's volume control, rather than have the minimum usable volume concentrated very close to the maximum volume. + +*Command Line Arguments* + +As previously mentioned, you can use command line arguments to provide settings to Shairport Sync as before, though newer settings will only be available via the configuration file. For full information, please read the Shairport Sync `man` page, also available at http://htmlpreview.github.io/?https://github.com/mikebrady/shairport-sync/blob/master/man/shairport-sync.html. + +Apart from the following options, all command line options can be replaced by settings in the configuration file. Here is a brief description of command line options that are not replicated by settings in the settings file. + +* The `-c` option allows you to specify the location of the configuration file. +* The `-V` option gives you version information about Shairport Sync and then quits. +* The `-d` option causes Shairport Sync to properly daemonise itself, that is, to run in the background. You may need sudo privileges for this. +* The `-k` option causes Shairport Sync to kill an existing Shairport Sync daemon. You may need to have sudo privileges for this. + +The System V init script at `/etc/init.d/shairport-sync` has a bare minimum : +`-d`. Basically all it does is put the program in daemon mode. The program will read its settings from the configuration file. + +Examples +-------- + +Here are some examples of complete configuration files. + +``` +general = { + name = "Joe's Stereo"; +}; + +alsa = { + output_device = "hw:0"; +}; +``` + +This gives the service a particular name — "Joe's Stereo" and specifies that audio device `hw:0` be used. + +For best results with the `alsa` backend — including getting true mute and instant response to volume control and pause commands — you should access the hardware volume controls. Use `amixer` or `alsamixer` or similar to discover the name of the mixer control to be used as the `mixer_control_name`. + +Here is an example for for a Raspberry Pi using its internal soundcard — device hw:0 — that drives the headphone jack: +``` +general = { + name = "Mike's Boombox"; +}; + +alsa = { + output_device = "hw:0"; + mixer_control_name = "PCM"; +}; +``` + +Here is an example of driving a Topping TP30 Digital Amplifier, which has an integrated USB DAC and which is connected as audio device `hw:1`: +``` +general = { + name = "Kitchen"; +}; + +alsa = { + output_device = "hw:1"; + mixer_control_name = "PCM"; +}; +``` + +For a cheapo "3D Sound" USB card (Stereo output and input only) on a Raspberry Pi: +``` +general = { + name = "Front Room"; +}; + +alsa = { + output_device = "hw:1"; + mixer_control_name = "Speaker"; +}; +``` + +For a first generation Griffin iMic on a Raspberry Pi: +``` +general = { + name = "Attic"; +}; + +alsa = { + output_device = "hw:1"; + mixer_control_name = "PCM"; +}; +``` + +For an NSLU2, which has no internal sound card, there appears to be a bug in ALSA — you can not specify a device other than "default". Thus: + +On an NSLU2, to drive a first generation Griffin iMic: +``` +general = { + name = "Den"; +}; + +alsa = { + mixer_control_name = "PCM"; +}; +``` + +On an NSLU2, to drive the "3D Sound" USB card: +``` +general = { + name = "TV Room"; +}; + +alsa = { + mixer_control_name = "Speaker"; +}; +``` + +Finally, here is an example of using the PulseAudio backend: +``` +general = { + name = "Zoe's Computer"; + output_backend = "pa"; +}; + +``` + + +Latency +------- +Latency is the exact time from a sound signal's original timestamp until that signal actually "appears" on the output of the audio output device, usually a Digital to Audio Converter (DAC), irrespective of any internal delays, processing times, etc. in the computer. + +Shairport Sync uses latencies supplied by the source, typically either 2 seconds or just over 2.25 seconds. You shouldn't need to change them. + +Problems can arise when you are trying to synchronise with speaker systems — typically surround-sound home theatre systems — that have their own inherent delays. You can compensate for an inherent delay using the appropriate backend (typically `alsa`) `audio_backend_latency_offset_in_seconds`. Set this offset (in frames) to compensate for a fixed delay in the audio back end; for example, if the output device delays by 100 ms, set this to -0.1. + +Resynchronisation +------------- +Shairport Sync actively maintains synchronisation with the source. +If synchronisation is lost — say due to a busy source or a congested network — Shairport Sync will mute its output and resynchronise. The loss-of-sync threshold is a very conservative 0.050 seconds — i.e. the actual time and the expected time must differ by more than 50 ms to trigger a resynchronisation. Smaller disparities are corrected by insertions or deletions, as described above. +* You can vary the resync threshold, or turn resync off completely, with the `general` `resync_threshold_in_seconds` setting. + +Tolerance +--------- +Playback synchronisation is allowed to wander — to "drift" — a small amount before attempting to correct it. The default is 0.002 seconds, i.e. 2 ms. The smaller the tolerance, the more likely it is that overcorrection will occur. Overcorrection is when more corrections (insertions and deletions) are made than are strictly necessary to keep the stream in sync. Use the `statistics` setting to monitor correction levels. Corrections should not greatly exceed net corrections. +* You can vary the tolerance with the `general` `drift_tolerance_in_seconds` setting. + diff --git a/ADVANCED TOPICS/Metadata.md b/ADVANCED TOPICS/Metadata.md new file mode 100644 index 00000000..1620d1bc --- /dev/null +++ b/ADVANCED TOPICS/Metadata.md @@ -0,0 +1,19 @@ +# Metadata + +Shairport Sync can deliver metadata supplied by the source, such as Album Name, Artist Name, Cover Art, etc. +through a pipe or UDP socket to a recipient application program — see https://github.com/mikebrady/shairport-sync-metadata-reader for a sample recipient. +Sources that supply metadata include iTunes and the Music app in macOS and iOS. + + +## Metadata over UDP** + +As an alternative to sending metadata to a pipe, the `socket_address` and `socket_port` tags may be set in the metadata group to cause Shairport Sync +to broadcast UDP packets containing the track metadata. + +The advantage of UDP is that packets can be sent to a single listener or, if a multicast address is used, to multiple listeners. +It also allows metadata to be routed to a different host. However UDP has a maximum packet size of about 65000 bytes; while large enough for most data, Cover Art will often exceed this value. Any metadata exceeding this limit will not be sent over the socket interface. The maximum packet size may be set with the `socket_msglength` tag to any value between 500 and 65000 to control this - lower values may be used to ensure that each UDP packet is sent in a single network frame. The default is 500. Other than this restriction, metadata sent over the socket interface is identical to metadata sent over the pipe interface. + +The UDP metadata format is very simple - the first four bytes are the metadata *type*, and the next four bytes are the metadata *code* +(both are sent in network byte order - see https://github.com/mikebrady/shairport-sync-metadata-reader for a definition of those terms). +The remaining bytes of the packet, if any, make up the raw value of the metadata. + diff --git a/ADVANCED TOPICS/README.md b/ADVANCED TOPICS/README.md new file mode 100644 index 00000000..f2090549 --- /dev/null +++ b/ADVANCED TOPICS/README.md @@ -0,0 +1,17 @@ +# Advanced Topics +Here you will find links to some advanced features and things you can do with Shairport Sync. +* [Finish setting up](InitialConfiguration.md). +* [Get the best](GetTheBest.md) from your system. +* [Metadata](Metadata.md). +* [Events](Events.md). +* [Statistics](Statistics.md). +* Setting up an [MQTT](../MQTT.md) system. +* [Digital Signal Processing](https://github.com/mikebrady/shairport-sync/wiki/Digital-Signal-Processing-with-Shairport-Sync). +* [Car Installation](../CAR%20INSTALL.md) +– build an isolated WiFi network containing a Shairport Sync player on a Raspberry Pi. Suitable for a car radio with an `aux` input or for the stereo in that broadband-free holiday cottage. + +The configuration file -- which contains lots of documentation -- is on your system. By default, the sample configuration file is +placed at `/etc/shairport-sync.conf.sample` (`/usr/local/etc/shairport-sync.conf.sample` on FreeBSD). +You can also view an online version [here](https://github.com/mikebrady/shairport-sync/blob/master/scripts/shairport-sync.conf). + +Build configuration flags are discussed [here](CONFIGURATION%20FLAGS.md). diff --git a/ADVANCED TOPICS/Statistics.md b/ADVANCED TOPICS/Statistics.md new file mode 100644 index 00000000..581c9559 --- /dev/null +++ b/ADVANCED TOPICS/Statistics.md @@ -0,0 +1,118 @@ +# Statistics + +If you set the `statistics` setting in the `diagnostics` section of the configuration file to `"YES"`, some statistics will be logged at regular intervals. The items logged will depend on the type of stream being processed: AirPlay 1, AirPlay 2 Buffered Audio or AirPlay 2 Realtime Audio. If the `log_verbosity` is set to 1, 2 or 3, additional items will be logged. + +From an audio enthusiast's point of view, the most important figure is possibly the `All Sync PPM` figure. This is the total amount of interpolation needed by Shairport Sync to keep the audio stream in sync. The number represents is the ratio of frames added and removed from the audio stream relative to all the frames output in the last interval, expressed in parts per million (PPM). For reference, adding or removing one frame per second into a 44,100 frames per second stream is ± 22.68 PPM. The lower this number number is, the higher the fidelity of the audio signal passed to the output device. On a well sorted system, this figure can be 0.0 for considerable periods, but it can't really be zero forever unless the output device is adapting to the true data rate (some very high-end streamers seem to do so). You may also find that the number might be higher at the start while the system settles down. + +The second most important figure is possibly the `Sync Error ms`. This is the average synchronisation error in milliseconds in the last interval. Ideally it should be 0.0. By default, Shairport Sync has a tolerance of a sync error of ± 2.0 milliseconds without triggering interpolation. + +Two other interesting measurements of the output rate may be available -- `Output FPS (r)` and `Output FPS (c)`, where `(r)` means "raw" and the `(c)` means "corrected". + +The "raw" figure is the rate at which the output device (typically a DAC) accepts data measured relative to the computer's own system clock (specifically the `CLOCK_MONOTONIC_RAW` clock). The accuracy of the number depends on the accuracy of the clock, which will typically be accurate to within anything from 20 to 100 ppm. + +The "corrected" figure is the rate at which the output device accepts data relative to the computer's network-time-disciplined clock (specifically the `CLOCK_MONOTONIC` clock). This clock is normally adjusted ("disciplined") to keep time with network time and should be accurate to with a few tens of milliseconds over a _long_ period. So (1) if you could run a play session for a long period -- say a day -- and (2) if network time synchronisation is enabled and (3) if the network connection to the network time service is fast and stable, then you should get an accurate absolute measure of exact frame rate of the output device. If your internet connection is not good, the corrected figure will be very inaccurate indeed. + +Here is a brief description of the figures that might be provided. +##### Sync Error ms +Average playback synchronisation error in milliseconds in the last interval. By default, Shairport Sync will allow a sync error of ± 2.0 milliseconds without any interpolation. Positive means late, negative means early. +##### Net Sync PPM +This is the total amount of interpolation done by Shairport Sync to keep the audio stream in sync. The number represents is the total number of frames added and removed from the audio stream, expressed in parts per million (PPM) in the last interval. For reference, adding or removing one frame per second into a 44,100 frames per second stream is 22.68 ppm. +##### All Sync PPM +This is the net amount of interpolation done by Shairport Sync to keep the audio stream in sync. The number represents is the number of frames added plus the number removed from the audio stream, expressed in parts per million (PPM) in the last interval. The magnitude of this should be the same as the `net sync ppm'. If it is much larger it means that Shairport Sync is overcorrecting for sync errors -- try increasing the drift tolerance to reduce it. +##### Packets +This is the number of packets of audio frames received since the start of the session. A packet normally contains 352 ± 1 audio frames. +##### Missing +This is the number of packets of audio frames that were expected but not received in the last interval. It should be zero, and if not it usually indicates a significant problem with the network. AirPlay 1 and AirPlay 2 Realtime Streams only. +##### Late +This is the number of packets of audio frames that were received late -- but still in time to be used -- in the last interval. AirPlay 1 and AirPlay 2 Realtime Streams only. +##### Too Late +This is the number of packets of audio frames that were received too late to be used in the last interval. It is possible that these packets were already received, so those frames might not actually be missing when the time comes to play them. AirPlay 1 and AirPlay 2 Realtime Streams only. +##### Resend Reqs +This is the number of times Shairport Sync requests the resending of missing frames. Requests can be for one or more frames. AirPlay 1 and AirPlay 2 Realtime Streams only. +##### Min DAC Queue +The is the smallest number of frames of audio in the DAC's hardware queue. If it goes too low, the DAC may begin to underrun. +##### Min Buffers +The is the smallest number of packets of audio in the queue to be processed in the last interval. It is related to the overall latency in AirPlay 1 and AirPlay 2 Realtime Streams. If it comes close to zero it's often a sign that the network is poor. +##### Max Buffers +The is the largest number of packets of audio in the queue to be processed in the last interval. +##### Min Buffer Size +The is smallest remaining number of bytes in the Buffered Audio buffer in the last interval. It can legitimately be zero when a track ends or begins. If it reaches zero while a track is playing, it means that audio data is not arriving at Shairport Sync quickly enough and may indicate network problems. AirPlay 2 Buffered Audio streams only. +##### Nominal FPS +This is the rate specified in the AirPlay stream itself. AirPlay 1 only. +##### Received FPS +This is the rate at which frames are received from the network averaged since the start of the play session. AirPlay 1 only. +##### Output FPS (r) +Output rate measured relative to the computer system's clock since the start of the play session. See above for a discussion. +##### Output FPS (c) +Output rate measured relative to the network-clock-disciplined computer system's clock since the start of the play session. See above for a discussion. +##### Source Drift PPM +This is a measure of the difference between the source clock and Shairport Sync's clock expressed in parts per million. Only valid when 10 or more drift samples have been received. AirPlay 1 only. +##### Drift Samples +This is the number drift samples have been accepted for calculating the source drift. AirPlay 1 only. +#### Example +The following example is of an AirPlay 2 Buffered Audio Stream from a HomePod mini to a WiFi-connected Raspberry Pi 3 equipped with a Pimoroni "Audio DAC SHIM (Line-Out)" with `log_verbosity` set to `1` after 3 hours and 37 minutes of operation. The audio is from a radio station accessed through Apple Music: + +``` + 5.292055362 "rtsp.c:3112" Connection 1. AP2 Buffered Audio Stream. + 1.382815677 "player.c:2650" Connection 1: Playback Started -- AirPlay 2 Buffered. + 7.899808955 "player.c:2491" Sync Error ms | Net Sync PPM | All Sync PPM | Min DAC Queue | Min Buffer Size | Output FPS (r) | Output FPS (c) +... + 8.014025361 "player.c:2491" -1.69 2.8 2.8 7341 198k 44100.04 44100.35 + 7.992082237 "player.c:2491" -1.70 2.8 2.8 7332 188k 44100.04 44100.34 + 8.015987549 "player.c:2491" -1.68 0.0 0.0 7334 186k 44100.04 44100.35 + 8.010537393 "player.c:2491" -1.68 2.8 2.8 7335 187k 44100.04 44100.36 + 7.993940934 "player.c:2491" -1.85 0.0 0.0 7329 198k 44100.04 44100.37 + 8.015796195 "player.c:2491" -1.87 5.7 5.7 7325 194k 44100.04 44100.37 + 8.021665934 "player.c:2491" -1.92 5.7 5.7 7329 190k 44100.04 44100.37 + 7.990409477 "player.c:2491" -1.85 2.8 2.8 7347 201k 44100.04 44100.37 + 8.001858278 "player.c:2491" -1.96 17.0 17.0 7332 204k 44100.04 44100.37 + 8.007150986 "player.c:2491" -1.89 2.8 2.8 7327 195k 44100.04 44100.36 + 7.998612862 "player.c:2491" -1.87 2.8 2.8 7317 199k 44100.04 44100.36 + 8.020592653 "player.c:2491" -1.89 11.3 11.3 7323 203k 44100.04 44100.35 + 8.003245674 "player.c:2491" -1.89 8.5 8.5 7325 198k 44100.04 44100.35 + 7.990874789 "player.c:2491" -1.98 19.8 19.8 7103 197k 44100.04 44100.34 + 8.010600257 "player.c:2491" -1.85 2.8 2.8 7327 187k 44100.04 44100.33 + 8.004573122 "player.c:2491" -1.89 5.7 5.7 7327 187k 44100.04 44100.33 + 8.012853278 "player.c:2491" -1.89 5.7 5.7 7326 190k 44100.04 44100.32 + 8.005596664 "player.c:2491" -1.95 22.7 22.7 7322 165k 44100.04 44100.31 + 8.019198695 "player.c:2491" -1.85 5.7 5.7 7333 166k 44100.04 44100.31 + 7.999363382 "player.c:2491" -1.79 2.8 2.8 7349 153k 44100.04 44100.30 + 7.990332549 "player.c:2491" -1.87 5.7 5.7 7328 155k 44100.04 44100.29 + 8.012287445 "player.c:2491" -1.84 2.8 2.8 7352 185k 44100.04 44100.28 + 7.998929528 "player.c:2491" -1.94 14.2 14.2 7331 171k 44100.04 44100.28 + 8.008170622 "player.c:2491" -1.88 5.7 5.7 7327 188k 44100.04 44100.27 + 8.012935257 "player.c:2491" -1.87 19.8 19.8 7270 205k 44100.04 44100.26 + 8.006337966 "player.c:2491" -1.86 0.0 0.0 7334 199k 44100.04 44100.25 + 8.004206612 "player.c:2491" -1.76 2.8 2.8 7331 204k 44100.04 44100.25 + 7.998495257 "player.c:2491" -1.82 2.8 2.8 7329 204k 44100.04 44100.24 + 8.016859059 "player.c:2491" -1.88 2.8 2.8 7335 201k 44100.04 44100.23 + 7.993529320 "player.c:2491" -1.92 14.2 14.2 7329 205k 44100.04 44100.22 + 8.021956820 "player.c:2491" -1.96 11.3 11.3 7322 206k 44100.04 44100.21 + 8.006401820 "player.c:2491" -1.93 11.3 11.3 7322 199k 44100.04 44100.21 + 8.001469111 "player.c:2491" -1.89 5.7 5.7 7336 204k 44100.04 44100.20 + 7.995194320 "player.c:2491" -1.86 5.7 5.7 7330 202k 44100.04 44100.19 + 8.017805206 "player.c:2491" -1.99 22.7 22.7 7322 201k 44100.04 44100.18 + 7.995541038 "player.c:2491" -1.95 22.7 22.7 7331 203k 44100.04 44100.18 + 8.011463643 "player.c:2491" -1.87 0.0 0.0 7331 207k 44100.04 44100.17 + 7.995941403 "player.c:2491" -1.85 2.8 2.8 7331 206k 44100.04 44100.16 + 8.013330570 "player.c:2491" -1.71 2.8 2.8 7344 212k 44100.04 44100.15 + 8.012214580 "player.c:2491" -1.82 0.0 0.0 7333 203k 44100.04 44100.15 + 7.998585049 "player.c:2491" -1.85 8.5 8.5 7332 207k 44100.04 44100.14 + 8.023448799 "player.c:2491" -1.86 5.7 5.7 7328 206k 44100.04 44100.13 + 7.984586612 "player.c:2491" -1.87 8.5 8.5 7277 205k 44100.04 44100.12 + 8.017339372 "player.c:2491" -1.91 17.0 17.0 7327 207k 44100.04 44100.12 + 8.007090309 "player.c:2491" -1.94 17.0 17.0 7286 199k 44100.04 44100.11 + 8.007894164 "player.c:2491" -1.87 2.8 2.8 7334 201k 44100.04 44100.10 + 7.991787497 "player.c:2491" -1.89 2.8 2.8 7327 194k 44100.04 44100.09 + 8.019011611 "player.c:2491" -1.94 5.7 5.7 7323 185k 44100.04 44100.09 + 7.994695362 "player.c:2491" -1.99 14.2 14.2 7321 199k 44100.04 44100.08 + 8.010284632 "player.c:2491" -1.93 11.3 11.3 7325 191k 44100.04 44100.07 + 8.011451612 "player.c:2491" -1.87 8.5 8.5 7329 156k 44100.04 44100.09 + 7.993112549 "player.c:2491" -1.84 2.8 2.8 7330 150k 44100.04 44100.13 + 8.004971455 "player.c:2491" -1.77 11.3 11.3 7325 157k 44100.04 44100.16 + 8.010517133 "player.c:2491" -1.85 0.0 0.0 7322 182k 44100.04 44100.19 + 8.005598851 "player.c:2491" -2.00 39.7 39.7 7207 180k 44100.04 44100.22 + 8.006777965 "player.c:2491" -1.99 39.7 39.7 7320 183k 44100.04 44100.24 + 7.115508696 "player.c:1643" Connection 1: Playback Stopped. Total playing time 03:37:20. Output: 44100.04 (raw), 44100.24 (corrected) frames per second. +``` +For reference, a drift of one second per day is approximately 11.57 ppm. Left uncorrected, even a drift this small between two audio outputs will be audible after a short time. diff --git a/AIRPLAY2.md b/AIRPLAY2.md new file mode 100644 index 00000000..3b9bc7dc --- /dev/null +++ b/AIRPLAY2.md @@ -0,0 +1,38 @@ +# AirPlay 2 +Shairport Sync offers AirPlay 2 support for audio sources on iOS devices, Macs from macOS 10.15 (Catalina) onwards, HomePod minis and Apple TVs. + +## What Works +- AirPlay 2 audio for iOS, HomePod mini, AppleTV and Mac players. + * Audio is synchronised with other AirPlay 2 devices. + * Two types of audio are received by Shairport Sync – "Realtime" streams of CD quality ALAC (like "classic" AirPlay) and "Buffered Audio" streams of AAC stereo at 44,100 frames per second. + * The selection of stream type is made by the player. + * Realtime streams generally have a latency of about two seconds. Buffered Audio streams typically have a latency of half a second or less. + * In AirPlay 2 mode, Shairport Sync reverts to "classic" AirPlay when iTunes on macOS or macOS Music plays to multiple speakers and one of more of them is compatible with AirPlay only. + +- Devices running Shairport Sync in AirPlay 2 mode can be [added](https://github.com/mikebrady/shairport-sync/blob/development/ADDINGTOHOME.md) to the Home app. + +## What Does Not Work +- No AirPlay 2 for Windows iTunes. +- Remote control facilities are not implemented. +- AirPlay 2 from macOS prior to 10.15 (Catalina) is not supported. + +## General +Shairport Sync uses a companion application called [NQPTP](https://github.com/mikebrady/nqptp) ("Not Quite PTP") +for timing and synchronisation in AirPlay 2. NQPTP must run as `root` and must have exclusive access to ports `319` and `320`. + +Lossless and High Definition Lossless material is transcoded to AAC before it reaches Shairport Sync. + +## What You Need +AirPlay 2 support needs a slightly more powerful CPU for decoding and synchronisation and more memory for bigger buffers and larger libraries. A Raspberry Pi 2 or Raspberry Pi Zero 2 W or better is recommended. + +Here are some guidelines: +* Full access, including `root` privileges, to a system at least as powerful as a Raspberry Pi 2 or a Raspberry Pi Zero 2 W. +* Ports 319 and 320 must be free to use (i.e. they must not be in use by another service such as a PTP service) and must not be blocked by a firewall. +* An up-to-date Linux or FreeBSD. This is important, as some of the libraries must be the latest available. +* Shairport Sync will not run on a Mac because NQPTP, on which it relies, needs ports 319 and 320, which are already used by macOS. +* A version of the [FFmpeg](https://www.ffmpeg.org) library with an AAC decoder capable of decoding Floating Planar -- `fltp` -- material. There is a guide [here](https://github.com/mikebrady/shairport-sync/blob/development/TROUBLESHOOTING.md#aac-decoder-issues-airplay-2-only) to help you find out if your system has it. +* An audio output, for example an ALSA device (or `sndio` in FreeBSD). The device must be capable of running at 44,100 frames per second. You can use an `sps-alsa-explore`](https://github.com/mikebrady/sps-alsa-explore) to test the suitability of hardware ALSA audio devices on your device. +Other backends continue to work as with "classic" Shairport Sync. + +## Guides +* A building guide is available at [BUILD.md](https://github.com/mikebrady/shairport-sync/blob/development/BUILD.md). diff --git a/BUILD.md b/BUILD.md new file mode 100644 index 00000000..9525ee27 --- /dev/null +++ b/BUILD.md @@ -0,0 +1,195 @@ +# Build and Install Shairport Sync +This guide is for a basic installation of Shairport Sync in a recent (2018 onwards) Linux or FreeBSD. + +Shairport Sync can be built as an AirPlay 2 player (with [some limitations](https://github.com/mikebrady/shairport-sync/blob/development/AIRPLAY2.md#features-and-limitations)) or as "classic" Shairport Sync – a player for the older, but still supported, AirPlay (aka "AirPlay 1") protocol. Check ["What You Need"](https://github.com/mikebrady/shairport-sync/blob/development/AIRPLAY2.md#what-you-need) for some basic system requirements. + +Overall, you'll be building and installing two programs – Shairport Sync itself and [NQPTP](https://github.com/mikebrady/nqptp), a companion app that Shairport Sync uses for AirPlay 2 timing. If you are building classic Shairport Sync, NQPTP is unnecessary and can be omitted. + +In the commands below, note the convention that a `#` prompt means you are in superuser mode and a `$` prompt means you are in a regular unprivileged user mode. You can use `sudo` *("SUperuser DO")* to temporarily promote yourself from user to superuser, if permitted. For example, if you want to execute `apt-get update` in superuser mode and you are in user mode, enter `sudo apt-get update`. + +## 1. Prepare +#### Remove Old Copies of Shairport Sync +Before you begin building Shairport Sync, it's best to remove any existing copies of the application, called `shairport-sync`. Use the command `$ which shairport-sync` to find them. For example, if `shairport-sync` has been installed previously, this might happen: +``` +$ which shairport-sync +/usr/local/bin/shairport-sync +``` +Remove it as follows: +``` +# rm /usr/local/bin/shairport-sync +``` +Do this until no more copies of `shairport-sync` are found. +#### Remove Old Service Files +You should also remove any of the following service files that may be present: +* `/etc/systemd/system/shairport-sync.service` +* `/etc/systemd/user/shairport-sync.service` +* `/lib/systemd/user/shairport-sync.service` +* `/etc/init.d/shairport-sync` + +New service files will be installed if necessary at the `# make install` stage. +#### Reboot after Cleaning Up +If you removed any installations of Shairport Sync or any of its service files in the last two steps, you should reboot. + +## 2. Get Tools and Libraries +Okay, now let's get the tools and libraries for building and installing Shairport Sync (and NQPTP). + +### Debian / Raspberry Pi OS / Ubuntu +``` +# apt update +# apt upgrade # this is optional but recommended +# apt install --no-install-recommends build-essential git xmltoman autoconf automake libtool \ + libpopt-dev libconfig-dev libasound2-dev avahi-daemon libavahi-client-dev libssl-dev libsoxr-dev \ + libplist-dev libsodium-dev libavutil-dev libavcodec-dev libavformat-dev uuid-dev libgcrypt-dev xxd +``` +If you are building classic Shairport Sync, the list of packages is shorter: +``` +# apt update +# apt upgrade # this is optional but recommended +# apt-get install --no-install-recommends build-essential git xmltoman autoconf automake libtool \ + libpopt-dev libconfig-dev libasound2-dev avahi-daemon libavahi-client-dev libssl-dev libsoxr-dev +``` +### Fedora +For AirPlay 2 operation, _before you install the libraries_, please ensure the you have [enabled](https://docs.fedoraproject.org/en-US/quick-docs/setup_rpmfusion) RPM Fusion software repositories at least to the "Free" level. If this is not done, FFmpeg libraries will be installed that lack a suitable AAC decoder, preventing Shairport Sync from working in AirPlay 2 mode. +``` +# yum update +# yum install make automake gcc gcc-c++ \ + git xmltoman autoconf automake avahi-devel libconfig-devel openssl-devel popt-devel soxr-devel \ + ffmpeg ffmpeg-devel libplist-devel libsodium-devel libgcrypt-devel libuuid-devel vim-common \ + alsa-lib-devel +``` +If you are building classic Shairport Sync, the list of packages is shorter: +``` +# yum update +# yum install make automake gcc gcc-c++ \ + git xmltoman autoconf automake avahi-devel libconfig-devel openssl-devel popt-devel soxr-devel \ + alsa-lib-devel +``` +### Arch Linux +After you have installed the libraries, note that you should enable and start the `avahi-daemon` service. +``` +# pacman -Syu +# pacman -Sy git base-devel alsa-lib popt libsoxr avahi libconfig \ + libsndfile libsodium ffmpeg vim libplist +``` +If you are building classic Shairport Sync, the list of packages is shorter: +``` +# pacman -Syu +# pacman -Sy git base-devel alsa-lib popt libsoxr avahi libconfig +``` +Enable and start the `avahi-daemon` service. +``` +# systemctl enable avahi-daemon +# systemctl start avahi-daemon +``` +### FreeBSD +First, update everything: +``` +# freebsd-update fetch +# freebsd-update install +# pkg +# pkg update +``` +Next, install the Avahi subsystem. FYI, `avahi-app` is chosen because it doesn’t require X11. `nss_mdns` is included to allow FreeBSD to resolve mDNS-originated addresses – it's not actually needed by Shairport Sync. Thanks to [reidransom](https://gist.github.com/reidransom/6033227) for this. +``` +# pkg install avahi-app nss_mdns +``` +Add these lines to `/etc/rc.conf`: +``` +dbus_enable="YES" +avahi_daemon_enable="YES" +``` +Next, change the `hosts:` line in `/etc/nsswitch.conf` to +``` +hosts: files dns mdns +``` +Reboot for these changes to take effect. + +Next, install the packages that are needed for Shairport Sync and NQPTP: +``` +# pkg install git autotools pkgconf popt libconfig openssl alsa-utils \ + libplist libsodium ffmpeg e2fsprogs-libuuid vim +``` +If you are building classic Shairport Sync, the list of packages is shorter: +``` +# pkg install git autotools pkgconf popt libconfig openssl alsa-utils +``` +## 3. Build +### NQPTP +Skip this section if you are building classic Shairport Sync – NQPTP is not needed for classic Shairport Sync. + +Download, install, enable and start NQPTP from [here](https://github.com/mikebrady/nqptp). + +### Shairport Sync +#### Build and Install +Download Shairport Sync, check out the `development` branch and configure, compile and install it. Before executing the commands, please note the following: + +* If building for FreeBSD, replace `--with-systemd` with `--with-os=freebsd --with-freebsd-service`. +* Omit the `--with-airplay-2` from the `./configure` options if you are building classic Shairport Sync. +* If you wish to add extra features, for example an extra audio backend, take a look at the [configuration flags](https://github.com/mikebrady/shairport-sync/blob/development/CONFIGURATION%20FLAGS.md). For this walkthrough, though, please do not remove the `--with-alsa` flag. + +``` +$ git clone https://github.com/mikebrady/shairport-sync.git +$ cd shairport-sync +$ git checkout development +$ autoreconf -fi +$ ./configure --sysconfdir=/etc --with-alsa \ + --with-soxr --with-avahi --with-ssl=openssl --with-systemd --with-airplay-2 +$ make +# make install +``` +By the way, the `autoreconf` step may take quite a while – please be patient! + +## 4. Test +At this point, Shairport Sync should be built and installed but not running. If the user you are logged in as is a member of the unix `audio` group, Shairport Sync should run from the command line: +``` +$ shairport-sync +``` +* Add the `-v` command line option to get some diagnostics. +* Add the `--statistics` option to get some infomation about the audio received. + +The AirPlay service should appear on the network and the audio you play should come through to the default ALSA device. (Use `alsamixer` or similar to adjust levels.) + +If you have problems, please check the items in [Final Notes](final_notes) below, or in the [TROUBLESHOOTING.md](https://github.com/mikebrady/shairport-sync/blob/development/TROUBLESHOOTING.md) guide. + +Note: Shairport Sync will run indefinitely -- use Control-C it to stop it. + +## 5. Enable and Start Service +Once you are happy that Shairport Sync runs from the command line, you should Control-C out of it and enable and start the `shairport-sync` service. This will launch Shairport Sync automatically as a background "daemon" service when the system powers up: + +### Linux +``` +# systemctl enable shairport-sync +``` +### FreeBSD +To make the `shairport-sync` daemon load at startup, add the following line to `/etc/rc.conf`: +``` +shairport_sync_enable="YES" +``` +## 6. Check +Reboot the machine. The AirPlay service should once again be visible on the network and audio will be sent to the default ALSA device. + +## 7. Final Notes +A number of system settings can affect Shairport Sync. Please review them as follows: + +### Power Saving +If your computer has an `Automatic Suspend` Power Saving Option, you should experiment with disabling it, because your computer has to be available for AirPlay service at all times. +### WiFi Power Management – Linux +If you are using WiFi, you should turn off WiFi Power Management: +``` +# iwconfig wlan0 power off +``` +or +``` +# iw dev wlan0 set power_save off +``` +The motivation for this is that WiFi Power Management will put the WiFi system in low-power mode when the WiFi system is considered inactive. In this mode, the system may not respond to events initiated from the network, such as AirPlay requests. Hence, WiFi Power Management should be turned off. See [TROUBLESHOOTING.md](https://github.com/mikebrady/shairport-sync/blob/master/TROUBLESHOOTING.md#wifi-adapter-running-in-power-saving--low-power-mode) for more details. + +(You can find WiFi device names (e.g. `wlan0`) with `$ ifconfig`.) +### Firewall +If a firewall is running (some systems, e.g. Fedora, run a firewall by default), ensure it is not blocking ports needed by Shairport Sync and [NQPTP](https://github.com/mikebrady/nqptp/blob/main/README.md#firewall). + +## 8. Connect and enjoy... +### Add to Home +With AirPlay 2, you can follow the steps in [ADDINGTOHOME.md](https://github.com/mikebrady/shairport-sync/blob/development/ADDINGTOHOME.md) to add your device to the Apple Home system. +### Wait, there's more... +Shairport Sync has many extra [features](README.md#features) and [settings](https://github.com/mikebrady/shairport-sync/blob/development/scripts/shairport-sync.conf). For instance, you can [add an MQTT service](https://github.com/mikebrady/shairport-sync/blob/master/MQTT.md), change the AirPlay service name, adjust for delays in other equipment (many TVs and AVRs introduce slight delays in their audio processing chains) and more. Explore runtime settings in `/etc/shairport-sync.conf` or [here](https://github.com/mikebrady/shairport-sync/blob/development/scripts/shairport-sync.conf). Build configuration flags are [here](https://github.com/mikebrady/shairport-sync/blob/development/CONFIGURATION%20FLAGS.md). diff --git a/BUILDFORAP1.md b/BUILDFORAP1.md new file mode 100644 index 00000000..e173e594 --- /dev/null +++ b/BUILDFORAP1.md @@ -0,0 +1,3 @@ +# Build Instructions for AirPlay 1 + +This guide has been superseded by the general building guide at [BUILD.md](https://github.com/mikebrady/shairport-sync/blob/development/BUILD.md). diff --git a/BUILDFORAP2.md b/BUILDFORAP2.md new file mode 100644 index 00000000..cf856c48 --- /dev/null +++ b/BUILDFORAP2.md @@ -0,0 +1,3 @@ +# Building Shairport Sync for AirPlay 2 + +This guide has been superseded by the general building guide at [BUILD.md](https://github.com/mikebrady/shairport-sync/blob/development/BUILD.md). diff --git a/CAR INSTALL.md b/CAR INSTALL.md index d97d08e0..c101be89 100644 --- a/CAR INSTALL.md +++ b/CAR INSTALL.md @@ -1,66 +1,79 @@ # Shairport Sync for Cars -If your car audio has an AUX input, you can get AirPlay in your car using Shairport Sync. Together, Shairport Sync and an iPhone can give you access to internet radio, YouTube, Apple Music, Spotify, etc. on the move. While Shairport Sync is no substitute for CarPlay, the audio quality is often much better than Bluetooth. Your passengers can enjoy movies with the soundtrack on the car speakers. +If your car audio has an AUX input, you can get AirPlay in your car using Shairport Sync. Together, Shairport Sync and an iPhone or an iPad with cellular capability can give you access to internet radio, YouTube, Apple Music, Spotify, etc. on the move. While Shairport Sync is no substitute for CarPlay, the audio quality is often much better than Bluetooth. ## The Basic Idea -The basic idea is to use a small Linux computer to create an isolated WiFi network for the car and to run Shairport Sync on it to provide an AirPlay service. The audio goes via a DAC to the AUX input of your car audio system. - -The car WiFi network you create is isolated and local to your car, and since it isn't connected to the Internet, you don't really need to secure it with a password. Likewise, you don't really have to use a password to connect to the AirPlay service. - -When an iPhone or an iPad with cellular capability is connected to an isolated WiFi network like this, it can use its cellular connection to access the Internet. -This means it can connect to internet radio, YouTube, Apple Music, Spotify, etc. over the cellular network and play the audio through the car network to the AirPlay service provided by Shairport Sync. +The basic idea is to use a small Linux computer to create an isolated WiFi network (a "car network") and run Shairport Sync on it to provide an AirPlay service. An iPhone or an iPad with cellular capability can simultaneously connect to internet radio, YouTube, Apple Music, Spotify, etc. over the cellular network and send AirPlay audio through the car network to the AirPlay service provided by Shairport Sync. This sends the audio to the computer's DAC which is connected to the AUX input of your car audio. Note that Android devices can not, so far, do this trick of using the two networks simultaneously. ## Example -In this example, a Raspberry Pi Zero W and a Pimoroni PHAT DAC are used. This combination has been tested for over two years. Please note that some of the details of setting up networks are specific to the version of Linux used -- Raspbian Stretch or later. +In this example, a Raspberry Pi Zero 2 W and a Pimoroni PHAT DAC are used. Shairport Sync will be built for AirPlay 2 operation, but you can build it for "classic" AirPlay (aka AirPlay 1) operation if you prefer. A Pi Zero W is powerful enough for classic AirPlay. + +Please note that some of the details of setting up networks are specific to the version of Linux used -- Rasberry Pi OS (Bullseye) Lite or later. ### Prepare the initial SD Image -* Download the latest version of Raspbian Lite -- Stretch Lite of 2018-03-13 at the time of writing -- and install it onto an SD Card. -* Mount the card on a Linux machine. Two drives should appear -- a `boot` drive and a `rootfs` drive. Both of these need a little modification. -* Enable SSH service by creating a file called `ssh` on the `boot` drive. To do this, mount the drive and CD to its `boot` partition (since my username is `mike`, the drive is at `/media/mike/boot`): -``` -$ touch ssh -``` -* Also in the `boot` drive, edit the `config.txt` file to add the overlay needed for the sound card. This may not be necessary in your case, but in this example a Pimoroni PHAT is being used and it needs the following entry to be added: -``` -dtoverlay=hifiberry-dac -``` -* Next, some modifications need to be done to the `rootfs` drive to make the Pi connect to your main WiFi network. (This is a temporary measure to enable you to connect the Pi to your main network so that you can do all the software installation and updating of the software necessary. Later, the Pi will be configured to start its own isolated network.) On the `rootfs` drive, edit the file `etc/wpa_supplicant/wpa_supplicant.conf` (you'll need root privileges) and add the name and password of your main WiFi network (substitute your own network name and password in, but keep the quotation marks): -``` -network={ - ssid="Network Name" - psk="Password" -} +* Download the latest version of Raspberry Pi OS (Lite) -- Bullseye (Lite) of 2022-04-04 at the time of writing -- and install it onto an SD Card using `Raspberry Pi Imager`. The Lite version is preferable to the Desktop version as it doesn't include a sound server like PulseAudio or PipeWire that can prevent direct access to the audio output device. +* Before writing the image to the card, use the Settings control on `Raspberry Pi Imager` to set hostname, enable SSH and provide a username and password to use while building the system. Similarly, you can specify a wireless network the Pi will connect to while building the system. Later on the Pi will be configured to start its own isolated network. +* The next few steps are to add the overlay needed for the sound card. This may not be necessary in your case, but in this example a Pimoroni PHAT is being used. If you do not need to add an overlay, skip these steps. + * Mount the card on a Linux machine. Two drives should appear -- a `boot` drive and a `rootfs` drive. + * `cd` to the `boot` drive (since my username is `mike`, it will be `$ cd /media/mike/boot`). + * Edit the `config.txt` file to add the overlay needed for the sound card. This may not be necessary in your case, but in this example a Pimoroni PHAT is being used and it needs the following entry to be added: + ``` + dtoverlay=hifiberry-dac + ``` + * Close the file and carefully dismount and eject the two drives. *Be sure to dismount and eject the drives properly; otherwise they may be corrupted.* +* Remove the SD card from the Linux machine, insert it into the Pi and reboot. -``` -Close the file and carefully dismount and eject the two drives. Remove the SD card from the Linux machine, insert it into the Pi and reboot. After a short time, the Pi should appear on your network and you can SSH into it. To check that it has appeared on the network, try to ping it at `raspberrypi.local`. It may take a minute or so to appear. Once it has appeared on your network you can SSH into it and configure it. +After a short time, the Pi should appear on your network -- it may take a minute or so. To check, try to `ping` it at the `.local`, e.g. if the hostname is `bmw` then use `$ ping bmw.local`. Once it has appeared, you can SSH into it and configure it. ### Boot, Configure, Update -The first thing to do on a Pi would be to use the `raspi-config` tool to expand the file system to use the entire card. It might be useful to change the `hostname` too. Next, do the usual update and upgrade: +The first thing to do on a Pi would be to use the `raspi-config` tool to expand the file system to use the entire card. Next, do the usual update and upgrade: ``` # apt-get update # apt-get upgrade ``` -### Shairport Sync -First, install the packages needed by Shairport Sync: +### Build and Install +Let's get the tools and libraries for building and installing Shairport Sync (and NQPTP). + ``` -# apt-get install build-essential git xmltoman autoconf automake libtool libpopt-dev libconfig-dev libasound2-dev avahi-daemon libavahi-client-dev libssl-dev libsoxr-dev +# apt install --no-install-recommends build-essential git xmltoman autoconf automake libtool \ + libpopt-dev libconfig-dev libasound2-dev avahi-daemon libavahi-client-dev libssl-dev libsoxr-dev \ + libplist-dev libsodium-dev libavutil-dev libavcodec-dev libavformat-dev uuid-dev libgcrypt-dev xxd ``` -Next, download Shairport Sync, configure it, compile and install it: +If you are building classic Shairport Sync, the list of packages is shorter: +``` +# apt-get install --no-install-recommends build-essential git xmltoman autoconf automake libtool \ + libpopt-dev libconfig-dev libasound2-dev avahi-daemon libavahi-client-dev libssl-dev libsoxr-dev +``` + +#### NQPTP +Skip this section if you are building classic Shairport Sync – NQPTP is not needed for classic Shairport Sync. + +Download, install, enable and start NQPTP from [here](https://github.com/mikebrady/nqptp) following the guide for Linux. + +#### Shairport Sync +Download Shairport Sync, check out the `development` branch and configure, compile and install it. + +* Omit the `--with-airplay-2` from the `./configure` options if you are building classic Shairport Sync. + ``` $ git clone https://github.com/mikebrady/shairport-sync.git $ cd shairport-sync +$ git checkout development $ autoreconf -fi -$ ./configure --sysconfdir=/etc --with-alsa --with-avahi --with-ssl=openssl --with-soxr --with-systemd +$ ./configure --sysconfdir=/etc --with-alsa \ + --with-soxr --with-avahi --with-ssl=openssl --with-systemd --with-airplay-2 $ make -$ sudo make install +# make install ``` -*Do not* enable Shairport Sync to automatically start at boot time -- startup is organised differently. +The `autoreconf` step may take quite a while – please be patient! -Third, finish by configuring Shairport Sync. +**Note:** *Do not* enable Shairport Sync to start automatically at boot time -- later on in this installation, we will arrange for it to start after the network has been set up. + +### Configure Shairport Sync Here are the important options for the Shairport Sync configuration file at `/etc/shairport-sync.conf`: ``` // Sample Configuration File for Shairport Sync for Car Audio with a Pimoroni PHAT @@ -98,51 +111,35 @@ Disable both of these services from starting at boot time (this is because we wi #### Configure HostAPD Configure `hostapd` by creating `/etc/hostapd/hostapd.conf` with the following contents which will set up an open network with the name BMW. You might wish to change the name: ``` -# This is the name of the WiFi interface we configured above +# Thanks to https://wiki.gentoo.org/wiki/Hostapd#802.11b.2Fg.2Fn_triple_AP + +# The interface used by the AP interface=wlan0 -# Use the nl80211 driver with the brcmfmac driver -driver=nl80211 - -# This is the name of the network -- yours might be different +# This is the name of the network -- yours may be different ssid=BMW -# Use the 2.4GHz band +# "g" simply means 2.4GHz band hw_mode=g -# Use channel 6 -channel=9 +# Channel to use +channel=11 -# Enable 802.11n +# Limit the frequencies used to those allowed in the country +ieee80211d=1 + +# The country code +country_code=IE + +# Enable 802.11n support ieee80211n=1 -# Enable WMM +# QoS support, also required for full speed on 802.11n/ac/ax wmm_enabled=1 -# Enable 40MHz channels with 20ns guard interval -#ht_capab=[HT40][SHORT-GI-20][DSSS_CCK-40] - -# Accept all MAC addresses -macaddr_acl=0 - -# Use WPA authentication -#auth_algs=1 - -# Require clients to know the network name -ignore_broadcast_ssid=0 - -# Use WPA2 -#wpa=2 - -# Use a pre-shared key -#wpa_key_mgmt=WPA-PSK - -# The network passphrase -#wpa_passphrase=none - -# Use AES, instead of TKIP -#rsn_pairwise=CCMP ``` +Note that, since car network is isolated from the Internet, you don't really need to secure it with a password. + #### Configure DHCP server First, replace the contents of `/etc/dhcp/dhcpd.conf` with this: @@ -183,6 +180,7 @@ Configure the startup sequence by adding commands to `/etc/rc.local` to start `h /bin/systemctl start shairport-sync exit 0 + ``` As you can see, the effect of these commands is to start the WiFi transmitter, give the base station the IP address `10.0.10.1`, start a DHCP server and finally start the Shairport Sync service. @@ -195,7 +193,7 @@ From this point on, at least on the Raspberry Pi, if you reboot the machine, it ### Optimise startup time -- Raspberry Pi Specific -This is applicable to a Raspberry Pi only. Some of it may be applicable to other systems, but it has not been tested on them. There are quite a few services that are not necessary for this setup. Disabling them can shorten startup time. Running these commands disables them: +This is applicable to a Raspberry Pi only. Some of it may be applicable to other systems, but it has not been tested on them. There are quite a few services that are not necessary for this setup. Disabling them can improve startup time. Running these commands disables them: ```` sudo systemctl disable systemd-timesyncd.service diff --git a/CONFIGURATION FLAGS.md b/CONFIGURATION FLAGS.md new file mode 100644 index 00000000..85e654e9 --- /dev/null +++ b/CONFIGURATION FLAGS.md @@ -0,0 +1,178 @@ +# Configuration Flags +When the application is being built, these flags determine what capabilities are included in Shairport Sync. +For example, to include DSP capabilities – needed for a loudness filter – you would include the `--with-convolution` flag in the list of +options at the `./configure ...` stage when building the application. + +In the following sections, Shairport Sync's compilation configuration options are detailed by catgegory. + +## AirPlay 2 or AirPlay + +| Flag | +| ---- | +| `--with-airplay-2` | + +AirPlay 2 is the current version of the AirPlay protocol. It offers multi-room operation and integration with the Home application. However, the Shairport Sync implementation is doesn't support iTunes on Windows, and its integration with the Home app and support for remote control is incomplete. Additionally, it requires a somewhat more powerful computer system (Raspberry Pi 2 equivalent or better) and a recent (2018 or later) version of a Debian-like Linux, Alpine Linux or FreeBSD. It has not been tested on other Linux distributions such as OpenWrt. Finally, AirPlay 2 can be lossy – in one mode of operation, audio is encoded in 256kbps AAC. + +AirPlay (aka AirPlay 1) is an older version of the AirPlay protocol. If offers multi-room operation to iTunes on macOS or Windows, the Music app on macOS and some third-party computer applications such as [OwnTone](https://owntone.github.io/owntone-server/). It will run on lower powered machines, e.g. the original Raspberry Pi and many embedded devices. This version of AirPlay is lossless – audio is received in 44,100 frames per second 16-bit interleaved stereo ALAC format. It is compatible with a wider range of Linux distributions, back to around 2012. However, support for this version of AirPlay seems to be gradually waning. It does not offer multi-room operation to iOS, iPadOS or AppleTV and is incompatible with HomePod. It is not integrated with the Home app. + +To build Shairport Sync for AirPlay 2, include the `--with-airplay-2` option in the `./configure ...` options. You will also have to include extra libraries. Omitting this option will cause Shairport Sync to be built for the older AirPlay protocol. + +## Audio Output +| Flags | +| ----- | +| `--with-alsa` | +| `--with-sndio` | +| `--with-pa` | +| `--with-pw` | +| `--with-ao` | +| `--with-jack` | +| `--with-soundio` | +| `--with-stdout` | +| `--with-pipe` | + +Shairport Sync has a number of different "backends" that send audio to an onward destination, e.g. an audio subsystem for output to a Digital to Audio Converter and thence to loudspeakers, or to a pipe for further processing. You can use configuration options to include support for multiple backends at build time and select one of them at runtime. + +Here are the audio backend configuration options: + +- `--with-alsa` Output to the Advanced Linux Sound Architecture ([ALSA](https://www.alsa-project.org/wiki/Main_Page)) system. This is recommended for highest quality. +- `--with-sndio` Output to the FreeBSD-native [sndio](https://sndio.org) system. +- `--with-pa` Include the PulseAudio audio back end. +- `--with-pw` Output to the [PipeWire](https://pipewire.org) system. +- `--with-ao` Output to the [libao](https://xiph.org/ao/) system. No synchronisation. +- `--with-jack` Output to the [Jack Audio](https://jackaudio.org) system. +- `--with-soundio` Include an optional backend module for audio to be output through the [`soundio`](http://libsound.io) system. No synchronisation. +- `--with-stdout` Include an optional backend module to enable raw audio to be output through standard output (`STDOUT`). +- `--with-pipe` Include an optional backend module to enable raw audio to be output through a unix pipe. + +### PulseAudio and PipeWire +Many recent Linux distributions with a GUI -- "desktop" Linuxes -- use PulseAudio or PipeWire to handle sound. There are two things to consider with these sound servers: +1. They may not always be available: a sound server generally becomes available when a user logs in via the GUI and disappears when the user logs out; it is not available when the system starts up and it is not available to non-GUI users. This means that Shairport Sync can not run as a daemon (see "Daemonisation" below) using a sound server unless the sound server is configured as a system-wide service. +2. The fidelity of the audio is unknown: once audio is delivered to the sound server, it is unknown what happens to it as it is processed through PulseAudio to arrives eventually at the loudspeakers. + +It should be noted that both PulseAudio and PipeWire provide a default ALSA pseudo device that enables ALSA-compatible programs to send audio. Shairport Sync can therefore use the ALSA backend with PulseAudio- or PipeWire-based systems. + +## Audio Options +| Flags | +| ----- | +| `--with-soxr` | +| `--with-apple-alac` | +| `--with-convolution` | + +- `--with-soxr` Allows Shairport Sync to use [libsoxr](https://sourceforge.net/p/soxr/wiki/Home/)-based resampling for improved interpolation. Recommended. +- `--with-apple-alac` Allows Shairport Sync to use the Apple ALAC Decoder. Requires [`libalac`](https://github.com/mikebrady/alac). +- `--with-convolution` Includes a convolution filter that can be used to apply effects such as frequency and phase correction, and a loudness filter that compensates for the non-linearity of the human auditory system. Requires `libsndfile`. + +## Metadata +| Flags | +| ----- | +| `--with-metadata` | + +Metadata such as track name, artist name, album name, cover art and more can be requested from the player and passed to other applications. + +- `--with-metadata` Adds support for Shairport Sync to request metadata and to pipe it to a compatible application. See https://github.com/mikebrady/shairport-sync-metadata-reader for a sample metadata reader. + +## Inter Process Communication + +| Flags | +| ----- | +| `--with-mqtt-client` | +| `--with-dbus-interface` | +| `--with-dbus-test-client` | +| `--with-mpris-interface` | +| `--with-mpris-test-client` | + +Shairport Sync offers three Inter Process Communication (IPC) interfaces: an [MQTT](https://mqtt.org) interface, an [MPRIS](https://specifications.freedesktop.org/mpris-spec/latest/)-like interface and a Shairport Sync specific "native" D-Bus interface loosely based on MPRIS. +The options are as follows: + +- `--with-mqtt-client` Includes a client for [MQTT](https://mqtt.org), +- `--with-dbus-interface` Includes support for the native Shairport Sync D-Bus interface, + - `--with-dbus-test-client` Compiles a D-Bus test client application, +- `--with-mpris-interface` Includes support for a D-Bus interface conforming as far as possible with the MPRIS standard, + - `--with-mpris-test-client` Compiles an MPRIS test client application. + +D-Bus and MPRIS commands and properties can be viewed using utilities such as [D-Feet](https://wiki.gnome.org/Apps/DFeet). + +##### MPRIS +The MPRIS interface has to depart somewhat from full MPRIS compatibility due to logical differences between Shairport Sync and a full standalone audio player such as Rhythmbox. Basically there are some things that Shairport Sync itself can not control that a standalone player can control. +A good example is volume control. MPRIS has a read-write `Volume` property, so the volume can be read or set. However, all Shairport Sync can do is *request* the player to change the volume control. This request may or may not be carried out, and it may or may not be done accurately. So, in Shairport Sync's MPRIS interface, `Volume` is a read-only property, and an extra command called `SetVolume` is provided. + +## Other Configuration Options + +### Configuration Files +| Flags | +| ----- | +| `--sysconfdir=` | + +Shairport Sync will look for a configuration file – `shairport-sync.conf` by default – when it starts up. By default, it will look in the directory specified by the `sysconfdir` configuration variable, which defaults to `/usr/local/etc`. This is normal in BSD Unixes, but is unusual in Linux. Hence, for Linux installations, you need to set the `sysconfdir` variable to `/etc` using the configuration setting `--sysconfdir=/etc`. + +### Daemonisation +| Flags | +| ----- | +| `--with-libdaemon` | +| `--with-piddir=` | + +A [daemon](https://en.wikipedia.org/wiki/Daemon_(computing)) is a computer program that runs as a background process, rather than being under the direct control of an interactive user. Shairport Sync is designed to run as a daemon. +FreeBSD and most recent Linux distributions can run an application as a daemon without special modifications. However, in certain older distributions and in special cases it may be necessary to enable Shairport Sync to daemonise itself. Use the `--with-libdaemon` configuration option: + +- `--with-libdaemon` Includes a demonising library needed if you want Shairport Sync to demonise itself with the `-d` option. Not needed for `systemd`-based systems which demonise programs differently. +- `--with-piddir=` Specifies a pathname to a directory in which to write the PID file which is created when Shairport Sync daemonises itself and used to locate the deamon process to be killed with the `-k` command line option. + +### Automatic Start +| Flags | +| ----- | +| `--with-systemd` | +| `--with-systemdsystemunitdir=` | +| `--with-systemv` | +| `--with-freebsd-service` | +| `--with-sygwin-service` | + +Daemon programs such as Shairport Sync need to be started automatically, so that the service they provide becomes available without further intervention. Typically this is done using startup scripts. Four options are provided – two for Linux, one for FreeBSD and one for CYGWIN. In Linux, the choice depends on whether [systemd](https://en.wikipedia.org/wiki/Systemd) is used or not. If `systemd` is installed, then the `--with-systemd` option is suggested. If not, the `--with-systemv` option is suggested. + +- `--with-systemd` Includes a script to create a Shairport Sync service that can optionally launch automatically at startup on `systemd`-based Linuxes. Default is not to to install. Note: an associated special-purpose option allows you to specify where the `systemd` service file will be placed: + - `--with-systemdsystemunitdir=` Specifies the directory for `systemd` service files. +- `--with-systemv` Includes a script to create a Shairport Sync service that can optionally launch automatically at startup on System V based Linuxes. Default is not to to install. +- `--with-freebsd-service` Includes a script to create a Shairport Sync service that can optionally launch automatically at startup on FreeBSD. Default is not to to install. +- `--with-cygwin-service` Includes a script to create a Shairport Sync service that can optionally launch automatically at startup on CYGWIN. Default is not to to install. + +### Cryptography +| Flags | +| ----- | +| `--with-ssl=openssl` | +| `--with-ssl=mbedtls` | +| `--with-ssl=polarssl` | + +AirPlay 2 operation requires the OpenSSL libraries, so the option `--with-ssl=openssl` is mandatory. + +For classic Shairport Sync, the options are as follows: + +- `--with-ssl=openssl` Uses the [OpenSSL](https://www.openssl.org) cryptography toolkit. This is mandatory for AirPlay 2 operation. +- `--with-ssl=mbedtls` Uses the [Mbed TLS](https://github.com/Mbed-TLS/mbedtls) cryptography library. Only suitable for classic AirPlay operation – do not include it in an AirPlay 2 configuration. +- `--with-ssl=polarssl` Uses the PolarSSL cryptography library. This is deprecated – PolarSSL has been replaced by Mbed TLS. Only suitable for classic AirPlay operation – do not include it in an AirPlay 2 configuration. + +### Zeroconf/Bonjour +| Flags | +| ----- | +| `--with-avahi` | +| `--with-tinysvcmdns` | +| `--with-external-mdns` | +| `--with-dns_sd` | + +AirPlay devices advertise their existence and status using [Zeroconf](http://www.zeroconf.org) (aka [Bonjour](https://en.wikipedia.org/wiki/Bonjour_(software))). + +AirPlay 2 operation requires the [Avahi](https://www.avahi.org) libraries, so the option `--with-avahi` is mandatory. + +For classic Shairport Sync, the options are as follows: + +The Zeroconf-related options are as follows: +- `--with-avahi` Chooses [Avahi](https://www.avahi.org)-based Zeroconf support. This is mandatory for AirPlay 2 operation. +- `--with-tinysvcmdns` Chooses [tinysvcmdns](https://github.com/philippe44/TinySVCmDNS)-based Zeroconf support (deprecated). +- `--with-external-mdns` Supports the use of ['avahi-publish-service'](https://linux.die.net/man/1/avahi-publish-service) or 'mDNSPublish' to advertise the service on Bonjour/ZeroConf. +- `--with-dns_sd` Chooses `dns-sd` Zeroconf support. + +### Miscellaneous +| Flag | Significance | +| -------------------- | ---- | +| `--with-os=` | Specifies the Operating System to target: One of `linux` (default), `freebsd`, `openbsd` or `darwin`. | +| `--with-configfiles` | Installs configuration files (including a sample configuration file) during `make install`. | +| `--with-pkg-config` | Specifies the use of `pkg-config` to find libraries. (Obselete for AirPlay 2. Special purpose use only.) | + diff --git a/CYGWIN.md b/CYGWIN.md index 80cb3517..491ca7c1 100644 --- a/CYGWIN.md +++ b/CYGWIN.md @@ -1,4 +1,4 @@ -Installing Shairport Sync into Cygwin +Installing Shairport Sync into Cygwin [Airplay 2 Not Supported] ==== This guide is based on installing onto a fresh installation of Cygwin 2.895 (64-bit installation) running in Windows 10 diff --git a/FEDORA.md b/FEDORA.md index 7690dbd6..7a8fd57a 100644 --- a/FEDORA.md +++ b/FEDORA.md @@ -1,28 +1,3 @@ -Fedora Installation Guide ------ -Update everything... -``` -# yum update -``` -Install the toolchain and pre-requisites, if necessary: -``` -# yum install make automake gcc gcc-c++ kernel-devel -# yum install alsa-lib-devel autoconf automake avahi-devel libconfig-devel \ - libdaemon-devel openssl-devel popt-devel soxr-devel rpmbuild -``` -Download the tarball from the "releases" tab on github or use `wget` and then use `rpmbuild`. Alternatively, download a tarball of the `master` branch, as in this example: -``` -$ wget -O shairport-sync-master.tar.gz https://github.com/mikebrady/shairport-sync/archive/master.tar.gz -$ rpmbuild -ta shairport-sync-master.tar.gz -``` -The `-ta` means "build all from this tarball". +# Fedora Installation Guide -The RPM will be built in a directory and will have a pathname like, for example, `~/rpmbuild/RPMS/i686/shairport-sync-2.6-1.fc22.i686.rpm` You should then install it with (for this example): -``` -$ sudo rpm -i ~/rpmbuild/RPMS/i686/shairport-sync-2.6-1.fc22.i686.rpm -``` -You may have to manually create the directory `/var/shairport-sync` beforehand for the installation to succeed. Having edited the configuration file `/etc/shairport-sync.conf` as appropriate (see [Configuring Shairport Sync](https://github.com/mikebrady/shairport-sync/blob/master/README.md#configuring-shairport-sync)), enable and start the service with: -``` -# systemctl enable shairport-sync.service -# systemctl start shairport-sync.service -``` +For the present, this guide has been superseded by the general building guide at [BUILD.md](https://github.com/mikebrady/shairport-sync/blob/development/BUILD.md). diff --git a/FREEBSD.md b/FREEBSD.md index fe3a2a5e..8a95a4ab 100644 --- a/FREEBSD.md +++ b/FREEBSD.md @@ -1,99 +1,3 @@ -Shairport Sync on FreeBSD using `sndio` ----- -Shairport Sync runs natively on FreeBSD using the `sndio` back end, thanks to the work of [Tobias Kortkamp (t6)](https://github.com/t6). +# Shairport Sync on FreeBSD -[`sndio`](http://www.sndio.org) is *"a small audio and MIDI framework part of the OpenBSD project and ported to FreeBSD, Linux and NetBSD"* developed by Alexandre Ratchov (see also [this paper](http://www.openbsd.org/papers/asiabsdcon2010_sndio.pdf) for more details). - -This is an initial note about installing Shairport Sync on FreeBSD. - -The build instructions here install back ends both for `sndio` and ALSA. ALSA is, or course, the Advanced Linux Sound Architecture, so it is not "native" to FreeBSD, but has been ported to some architectures under FreeBSD. - -General ----- -This build was done on a default build of `FreeBSD 11.0-RELEASE-p9`. - -First, update everything: -``` -# freebsd-update fetch -# freebsd-update install -``` -Next, install the `pkg` package manager and update its lists: - -``` -# pkg -# pkg update -``` - -Subsystems ----- -Install the Avahi subsystem. FYI, `avahi-app` is chosen because it doesn’t require X11. `nss_mdns` is included to allow FreeBSD to resolve mDNS-originated addresses – it's not actually needed by Shairport Sync. Thanks to [reidransom](https://gist.github.com/reidransom/6033227) for this. - -``` -# pkg install avahi-app nss_mdns -``` -Add these lines to `/etc/rc.conf`: -``` -dbus_enable="YES" -avahi_daemon_enable="YES" -``` -Next, change the `hosts:` line in `/etc/nsswitch.conf` to -``` -hosts: files dns mdns -``` -Reboot for these changes to take effect. - -Building ----- - -Install the packages that are needed for Shairport Sync to be downloaded and built successfully: -``` -# pkg install git autotools pkgconf popt libconfig openssl sndio alsa-utils -``` -Add `alsa-utils` if you're wish to use ALSA. Omit `sndio` if you don't intend to use the `sndio` subsystem. - -Now, download Shairport Sync from GitHub: -``` -$ git clone https://github.com/mikebrady/shairport-sync.git -$ cd shairport-sync -``` -Next, configure the build and compile it: - -``` -$ autoreconf -i -f -$ ./configure --with-libdaemon --with-avahi --with-ssl=openssl --with-sndio --with-libdaemon --with-os=freebsd --with-freebsd-service -$ make -``` -Add `--with-alsa` if you wish to include the ALSA back end. Omit the `--with-sndio` if you don't want the `sndio` back end. Omit the `--with-freebsd-service` if you don't want to install a FreeBSD startup script, runtime folder and user and group -- see below for more details. - -Installation ----- - -Enter the superuser mode and do a `make install`: - -``` -$ su -# make install -``` - -With the `./configure` options shown above, this will install the `shairport-sync` program along with a sample configuration file at `/usr/local/etc/shairport-sync.conf`. A service startup script will also be installed to launch Shairport Sync as a daemon. In addition, a `shairport-sync` user and group will be added and a directory will be created at `/var/run/shairport-sync` owned by the user `shairport-sync`. This will be used to hold the daemon's PID file. - -Finally, edit `/usr/local/etc/shairport-sync.conf` to customise your installation, e.g. service name, etc. To make the `shairport-sync` daemon load at startup, add the following line to `/etc/rc.conf`: - -``` -shairport_sync_enable="YES" -``` -You can launch the service as superuser, or simply reboot the machine. - -Using the `sndio` backend ----- - -The `sndio` back end does not yet have a hardware volume control facility. You should set the volume to maximum before use, using, for example, the `mixer` command described below. - -Setting Overall Volume ----- -The `mixer` command can be used for setting the output device's volume settings. You may have to experiment to figure out which settings are appropriate. - -``` -$ mixer vol 100 # sets overall volume -``` -If you've installed `alsa-utils`, then `alsamixer` and friends will also be available. +This guide has been superseded by the general building guide at [BUILD.md](https://github.com/mikebrady/shairport-sync/blob/development/BUILD.md). diff --git a/INSTALL.md b/INSTALL.md deleted file mode 100644 index 9cdd622c..00000000 --- a/INSTALL.md +++ /dev/null @@ -1,116 +0,0 @@ -Simple Installation Instructions -== -Here are simple instructions for building and installing Shairport Sync on a Raspberry Pi B, 2B, 3B, 3B+ or 4B. It is assumed that the Pi is running Raspbian Buster Lite – a GUI isn't needed, since Shairport Sync runs as a daemon program. For a more thorough treatment, please go to the [README.md](https://github.com/mikebrady/shairport-sync/blob/master/README.md#building-and-installing) page. - -In the commands below, note the convention that a `#` prompt means you are in superuser mode and a `$` prompt means you are in a regular unprivileged user mode. You can use `sudo` *("SUperuser DO")* to temporarily promote yourself from user to superuser, if permitted. For example, if you want to execute `apt-get update` in superuser mode and you are in user mode, enter `sudo apt-get update`. - -### Configure and Update -Do the usual update and upgrade: -``` -# apt-get update -# apt-get upgrade -``` -(Separately, if you haven't done so already, consider using the `raspi-config` tool to expand the file system to use the entire card.) - -### Turn Off WiFi Power Management -If you are using WiFi, you should turn off WiFi Power Management: -``` -# iwconfig wlan0 power off -``` -WiFi Power Management will put the WiFi system in low-power mode when the WiFi system is considered inactive, and in this mode it may not respond to events initiated from the network, such as AirPlay requests. Hence, WiFi Power Management should be turned off. (See [TROUBLESHOOTING.md](https://github.com/mikebrady/shairport-sync/blob/master/TROUBLESHOOTING.md#wifi-adapter-running-in-power-saving--low-power-mode) for more details.) - -Reboot the Pi. - -### Remove Old Copies -Before you begin building Shairport Sync, it's best to search for and remove any existing copies of the application, called `shairport-sync`. Use the command `$ which shairport-sync` to find them. For example, if `shairport-sync` has been installed previously, this might happen: -``` -$ which shairport-sync -/usr/local/bin/shairport-sync -``` -Remove it as follows: -``` -# rm /usr/local/bin/shairport-sync -``` -Do this until no more copies of `shairport-sync` are found. - -### Remove Old Startup and Service Scripts -You should also remove the startup script and service definition files `/etc/systemd/system/shairport-sync.service`, `/lib/systemd/system/shairport-sync.service`, `/etc/init.d/shairport-sync`, `/etc/dbus-1/system.d/shairport-sync-dbus.conf` and `/etc/dbus-1/system.d/shairport-sync-mpris.conf` if they exist – new ones will be installed if necessary. - -### Reboot after Cleaning Up -If you removed any installations of Shairport Sync or any of its startup script files in the last two steps, you should reboot. - -### Build and Install -Okay, now let's get the tools and sources for building and installing Shairport Sync. - -First, install the packages needed by Shairport Sync: -``` -# apt install --no-install-recommends build-essential git xmltoman autoconf automake libtool \ - libpopt-dev libconfig-dev libasound2-dev avahi-daemon libavahi-client-dev libssl-dev libsoxr-dev -``` -Next, download Shairport Sync, configure it, compile and install it: -``` -$ git clone https://github.com/mikebrady/shairport-sync.git -$ cd shairport-sync -$ autoreconf -fi -$ ./configure --sysconfdir=/etc --with-alsa --with-soxr --with-avahi --with-ssl=openssl --with-systemd -$ make -$ sudo make install -``` -By the way, the `autoreconf` step may take quite a while on a Raspberry Pi -- be patient! - -### Configure -If you don't set any configuration parameters, Shairport Sync will use the default `alsa` output device. - -If you wish to configure Shairport Sync to use a specific output device (recommended), an experimental tool called [sps-alsa-explore](https://github.com/mikebrady/sps-alsa-explore) is available to search for all `alsa` hardware output devices that can be used by Shairport Sync. Here is the tool's output for a Raspberry Pi 4 running Buster: - -``` -> Device: "hw:Headphones" - Short Name: "hw:0" - This device seems suitable for use with Shairport Sync. - Possible mixers: "Headphone" - Suggested rate and format: - Rate Format - 44100 S16_LE - -> Device: "hw:vc4hdmi0" - Short Name: "hw:2" - This device can not be accessed and so can not be checked. - (Does it need to be configured or connected?) - -> Device: "hw:vc4hdmi1" - Short Name: "hw:3" - This device can not be accessed and so can not be checked. - (Does it need to be configured or connected?) - -``` - -To use the "Headphones" device, here are the options for the Shairport Sync configuration file at `/etc/shairport-sync.conf`: -``` -// Sample Configuration File for Shairport Sync on a Raspberry Pi using the built-in audio DAC -general = -{ - volume_range_db = 60; -}; - -alsa = -{ - output_device = "hw:Headphones"; - mixer_control_name = "Headphone"; -}; - -``` -The `volume_range_db = 60;` setting makes Shairport Sync use only the usable part of the built-in audio card mixer's attenuation range. - -(BTW, Shairport Sync will choose the suggested speed and format automatically.) - -The next step is to enable Shairport Sync to start automatically on boot up: -``` -# systemctl enable shairport-sync -``` -Finally, either reboot the Pi or start the `shairport-sync` service: -``` -# systemctl start shairport-sync -``` -The Shairport Sync AirPlay service should now appear on the network with a service name made from the Pi's hostname with the first letter capitalised, e.g. hostname `raspberrypi` gives a service name `Raspberrypi`. You can change the service name and set a password in the configuration file. - -Connect and enjoy... diff --git a/MOREINFO.md b/MOREINFO.md new file mode 100644 index 00000000..147d195d --- /dev/null +++ b/MOREINFO.md @@ -0,0 +1,3 @@ +# More Information + +Information in this document has been updated and moved to [ADVANCED TOPICS](https://github.com/mikebrady/shairport-sync/blob/development/ADVANCED%20TOPICS/README.md). diff --git a/MQTT.md b/MQTT.md index da21a3fc..95779c76 100644 --- a/MQTT.md +++ b/MQTT.md @@ -1,3 +1,21 @@ +MQTT in Shairport Sync +==== +To enable Shairport Sync to act as an MQTT publisher, you need to: +1. Install the mosquitto library: +``` +# apt install libmosquitto-dev +``` +2. Add the configuration flag `--with-mqtt-client` to the list of parameters to the `./configure...` command, for example: +``` +$ ./configure --with-mqtt-client --sysconfdir=/etc --with-alsa --with-avahi --with-ssl=openssl --with-systemd +``` + +If Shairport Sync has MQTT support, it will have the string `mqtt` in its configuration string. For example: +``` +$ shairport-sync -V +3.3.8-OpenSSL-Avahi-ALSA-metadata-mqtt-sysconfdir:/etc +``` + Setting Up MQTT Publishing ==== @@ -77,31 +95,38 @@ The first 4-character code, called the `type`, is either: * For `ssnc` metadata, the second 4-character code is used to distinguish the messages. Cover art, coming from the source, is not tagged in the same way as other metadata, it seems, so is sent as an `ssnc` type metadata message with the code `PICT`. Progress information, similarly, is not tagged like other source-originated metadata, so it is sent as an `ssnc` type with the code `prgr`. Here are some of the `core` codes commonly passed from the source: - * `asar` -- "artist" - * `asal` -- "album" - * `minm` -- "title" - * `asgn` -- "genre" - * `asfm` -- "format" - * `asal` -- "songalbum' - * `pvol` -- "volume" - * `clip` -- "client_ip" + * `asal` -- album + * `asar` -- artist + * `ascp` -- composer + * `asgn` -- genre + * `astm` -- song time + * `caps` -- play status (stopped, paused, playing) + * `minm` -- title + * `mper` -- track persistent id Here are the 'ssnc' codes defined so far: * `PICT` -- the payload is a picture, either a JPEG or a PNG. Check the first few bytes to see which. - * `clip` -- the payload is the IP number of the client, i.e. the sender of audio. Can be an IPv4 or an IPv6 number. + * `acre` -- Active Remote + * `cdid` -- Client advertised Device ID + * `clip` -- the payload is the IP address of the client, i.e. the sender of audio. Can be an IPv4 or an IPv6 address. + * `cmac` -- Client advertised MAC address + * `cmod` -- Client advertised model ("iPhone14,2") + * `daid` -- DACP ID + * `dapo` -- DACP Port + * `mden` -- a sequence of metadata has ended. The RTP timestamp associated with the metadata sequence is included as data, if available. + * `mdst` -- a sequence of metadata is about to start. The RTP timestamp associated with the metadata sequence is included as data, if available. * `pbeg` -- play stream begin. No arguments + * `pcen` -- a picture has been sent. The RTP timestamp associated with it is included as data, if available. + * `pcst` -- a picture is about to be sent. The RTP timestamp associated with it is included as data, if available. * `pend` -- play stream end. No arguments * `pfls` -- play stream flush. No arguments * `prsm` -- play stream resume. No arguments - * `pvol` -- play volume. The volume is sent as a string -- "airplay_volume,volume,lowest_volume,highest_volume", where "volume", "lowest_volume" and "highest_volume" are given in dB. The "airplay_volume" is what's sent by the source (e.g. iTunes) to the player, and is from 0.00 down to -30.00, with -144.00 meaning "mute". This is linear on the volume control slider of iTunes or iOS AirPlay. If the volume setting is being ignored by Shairport Sync itself, the volume, lowest_volume and highest_volume values are zero. * `prgr` -- progress -- this is metadata from AirPlay consisting of RTP timestamps for the start of the current play sequence, the current play point and the end of the play sequence. - * `mdst` -- a sequence of metadata is about to start. The RTP timestamp associated with the metadata sequence is included as data, if available. - * `mden` -- a sequence of metadata has ended. The RTP timestamp associated with the metadata sequence is included as data, if available. - * `pcst` -- a picture is about to be sent. The RTP timestamp associated with it is included as data, if available. - * `pcen` -- a picture has been sent. The RTP timestamp associated with it is included as data, if available. - * `snam` -- a device e.g. "Joe's iPhone" has started a play session. Specifically, it's the "X-Apple-Client-Name" string. + * `pvol` -- play volume. The volume is sent as a string -- "airplay_volume,volume,lowest_volume,highest_volume", where "volume", "lowest_volume" and "highest_volume" are given in dB. The "airplay_volume" is what's sent by the source (e.g. iTunes) to the player, and is from 0.00 down to -30.00, with -144.00 meaning "mute". This is linear on the volume control slider of iTunes or iOS AirPlay. If the volume setting is being ignored by Shairport Sync itself, the volume, lowest_volume and highest_volume values are zero. + * `snam` -- a device e.g. "Joe's iPhone" has started a play session. Specifically, it's the "X-Apple-Client-Name" string for AP1, or direct from the configuration Plist for AP2. * `snua` -- a "user agent" e.g. "iTunes/12..." has started a play session. Specifically, it's the "User-Agent" string. * `stal` -- this is an error message meaning that reception of a large piece of metadata, usually a large picture, has stalled; bad things may happen. + * `svip` -- the payload is the IP address of the server, i.e. shairport-sync. Can be an IPv4 or an IPv6 address. Parsed Messages @@ -109,14 +134,21 @@ Parsed Messages The MQTT service can parse the above raw messages into a subset of human-readable topics that include, +* `active_remote_id` -- Active Remote ID * `artist` -- text of artist name * `album` -- text of album name -* `title` -- text of song title -* `genre` -- text of genre -* `format` -- ?? -* `songalbum` -- -* `volume` -- The volume is sent as a string -- "airplay_volume,volume,lowest_volume,highest_volume", where "volume", "lowest_volume" and "highest_volume" are given in dB. (see above) * `client_ip` -- IP address of the connected client +* `client_device_id` -- Client advertised Device ID +* `client_mac_address` -- Client advertised MAC address +* `client_model` -- Client advertised model ("iPhone14,2") +* `client_name` -- Client advertised name ("Joe's iPhone") +* `dacp_id` -- DACP ID +* `format` -- ?? +* `genre` -- text of genre +* `server_ip` -- IP address of shairport-sync that the client is connected to +* `songalbum` -- +* `title` -- text of song title +* `volume` -- The volume is sent as a string -- "airplay_volume,volume,lowest_volume,highest_volume", where "volume", "lowest_volume" and "highest_volume" are given in dB. (see above) and empty messages at the following topics are published. @@ -156,7 +188,7 @@ binary_sensor: off_delay: 300 ``` -Below parsed data is saved into the Home Assistant database as sensor data. Please not the conversion of the volume from dB to percentage. +Below parsed data is saved into the Home Assistant database as sensor data. Please note the conversion of the volume from dB to percentage. ```yml sensor: diff --git a/Makefile.am b/Makefile.am index c9ccb75e..666047ea 100644 --- a/Makefile.am +++ b/Makefile.am @@ -1,15 +1,28 @@ SUBDIRS = man ARFLAGS = cr + +lib_pair_ap_a_CFLAGS = -Wall -g -DCONFIG_GCRYPT -pthread +lib_tinyhttp_a_CFLAGS = -pthread lib_dbus_interface_a_CFLAGS = -pthread lib_mpris_interface_a_CFLAGS = -pthread bin_PROGRAMS = shairport-sync +BUILT_SOURCES = +noinst_HEADERS = +CLEANFILES = +shairport_sync_LDADD = +noinst_LIBRARIES = + # See below for the flags for the test client program shairport_sync_SOURCES = shairport.c rtsp.c mdns.c common.c rtp.c player.c alac.c audio.c loudness.c activity_monitor.c +if BUILD_FOR_DARWIN + AM_CXXFLAGS = -I/usr/local/include -Wno-multichar -Wall -Wextra -Wno-deprecated-declarations -pthread -DSYSCONFDIR=\"$(sysconfdir)\" + AM_CFLAGS = -Wno-multichar -Wall -Wextra -Wno-deprecated-declarations -pthread -DSYSCONFDIR=\"$(sysconfdir)\" +else if BUILD_FOR_FREEBSD AM_CXXFLAGS = -I/usr/local/include -Wno-multichar -Wall -Wextra -pthread -DSYSCONFDIR=\"$(sysconfdir)\" AM_CFLAGS = -Wno-multichar -Wall -Wextra -pthread -DSYSCONFDIR=\"$(sysconfdir)\" @@ -22,6 +35,19 @@ else AM_CFLAGS = -fno-common -Wno-multichar -Wall -Wextra -Wno-clobbered -Wno-psabi -pthread -DSYSCONFDIR=\"$(sysconfdir)\" endif endif +endif + +# include information generated by 'git describe --dirty' if requested +if USE_GIT_VERSION +common.c: gitversion.h +gitversion.h: .git/index + printf "// Do not edit!\n" > gitversion.h + printf "// This file is automatically generated by 'git describe --dirty', if available.\n" >> gitversion.h + printf " char git_version_string[] = \"" >> gitversion.h + git describe --dirty | tr -d '[[:space:]]' >> gitversion.h + printf "\";\n" >> gitversion.h +CLEANFILES += gitversion.h +endif if USE_APPLE_ALAC shairport_sync_SOURCES += apple_alac.cpp @@ -80,6 +106,10 @@ if USE_PA shairport_sync_SOURCES += audio_pa.c endif +if USE_PW +shairport_sync_SOURCES += audio_pw.c +endif + if USE_CONVOLUTION shairport_sync_SOURCES += FFTConvolver/AudioFFT.cpp FFTConvolver/FFTConvolver.cpp FFTConvolver/Utilities.cpp FFTConvolver/convolver.cpp AM_CXXFLAGS += -std=c++11 @@ -90,36 +120,54 @@ shairport_sync_SOURCES += mdns_dns_sd.c endif if USE_METADATA_HUB -shairport_sync_SOURCES += metadata_hub.c +shairport_sync_SOURCES += metadata_hub.c endif if USE_MQTT -shairport_sync_SOURCES += mqtt.c +shairport_sync_SOURCES += mqtt.c endif if USE_DACP_CLIENT -shairport_sync_SOURCES += dacp.c tinyhttp/chunk.c tinyhttp/header.c tinyhttp/http.c +shairport_sync_SOURCES += dacp.c +shairport_sync_LDADD += lib_tinyhttp.a +noinst_LIBRARIES += lib_tinyhttp.a +lib_tinyhttp_a_SOURCES = tinyhttp/chunk.c tinyhttp/header.c tinyhttp/http.c endif -BUILT_SOURCES = -noinst_HEADERS = -CLEANFILES = -shairport_sync_LDADD = -noinst_LIBRARIES = +if USE_AIRPLAY_2 +shairport_sync_SOURCES += ptp-utilities.c plist_xml_strings.c +shairport_sync_LDADD += lib_pair_ap.a +lib_pair_ap_a_SOURCES = pair_ap/pair.c pair_ap/pair_fruit.c pair_ap/pair_homekit.c pair_ap/pair-tlv.c +noinst_LIBRARIES += lib_pair_ap.a +plist_xml_strings.h: plists/get_info_response.xml + printf "// Do not edit!\n" > plist_xml_strings.h + printf "// This file is automatically generated from files in the plists folder.\n\n" >> plist_xml_strings.h + xxd -i $(top_srcdir)/plists/get_info_response.xml - | sed -e 's/[^ ]*plists_get_info_response_xml/plists_get_info_response_xml/g' >> plist_xml_strings.h + printf "\n" >> plist_xml_strings.h +plist_xml_strings.c: plist_xml_strings.h + touch plist_xml_strings.c + +BUILT_SOURCES += plist_xml_strings.c plist_xml_strings.h +noinst_HEADERS += $(BUILT_SOURCES) +# Correctly clean the generated headers, but keep the xml description +CLEANFILES += $(BUILT_SOURCES) +endif if USE_DBUS shairport_sync_LDADD += lib_dbus_interface.a noinst_LIBRARIES += lib_dbus_interface.a lib_dbus_interface_a_SOURCES = dbus-interface.c shairport_sync_SOURCES += dbus-service.c -BUILT_SOURCES += dbus-interface.h dbus-interface.c +BUILT_SOURCES += dbus-interface.h dbus-interface.c # We don't want to install this header noinst_HEADERS += $(BUILT_SOURCES) # Correctly clean the generated headers, but keep the xml description CLEANFILES += $(BUILT_SOURCES) + + dbus-interface.c: org.gnome.ShairportSync.xml - gdbus-codegen --interface-prefix org.gnome --generate-c-code dbus-interface org.gnome.ShairportSync.xml + gdbus-codegen --interface-prefix org.gnome --generate-c-code dbus-interface $(top_srcdir)/org.gnome.ShairportSync.xml dbus-interface.h: dbus-interface.c touch dbus-interface.h endif @@ -136,7 +184,7 @@ noinst_HEADERS += $(BUILT_SOURCES) CLEANFILES += $(BUILT_SOURCES) mpris-interface.c: org.mpris.MediaPlayer2.xml - gdbus-codegen --interface-prefix org.mpris --generate-c-code mpris-interface org.mpris.MediaPlayer2.xml + gdbus-codegen --interface-prefix org.mpris --generate-c-code mpris-interface $(top_srcdir)/org.mpris.MediaPlayer2.xml mpris-interface.h: mpris-interface.c touch mpris-interface.h endif @@ -157,54 +205,120 @@ shairport_sync_mpris_test_client_SOURCES = shairport-sync-mpris-test-client.c shairport_sync_mpris_test_client_LDADD = lib_mpris_interface.a endif -install-exec-hook: -if BUILD_FOR_LINUX -DBUS_POLICY_DIR=$(DESTDIR)/etc/dbus-1/system.d -else -DBUS_POLICY_DIR=$(DESTDIR)$(sysconfdir)/dbus-1/system.d -endif if INSTALL_CONFIG_FILES - [ -e $(DESTDIR)$(sysconfdir) ] || mkdir $(DESTDIR)$(sysconfdir) - cp scripts/shairport-sync.conf $(DESTDIR)$(sysconfdir)/shairport-sync.conf.sample - [ -f $(DESTDIR)$(sysconfdir)/shairport-sync.conf ] || cp scripts/shairport-sync.conf $(DESTDIR)$(sysconfdir)/shairport-sync.conf + +CONFIG_FILE_INSTALL_TARGET = config-file-install-local +$(CONFIG_FILE_INSTALL_TARGET): scripts/shairport-sync.conf + install -d $(DESTDIR)$(sysconfdir) + install -m 0644 $(top_srcdir)/scripts/shairport-sync.conf $(DESTDIR)$(sysconfdir)/shairport-sync.conf.sample + [ -f $(DESTDIR)$(sysconfdir)/shairport-sync.conf ] || cp $(top_srcdir)/scripts/shairport-sync.conf $(DESTDIR)$(sysconfdir)/shairport-sync.conf + +if BUILD_FOR_LINUX +DBUS_POLICY_DIR = /etc/dbus-1/system.d +else +DBUS_POLICY_DIR = $(sysconfdir)/dbus-1/system.d +endif + if USE_DBUS - [ -e $(DBUS_POLICY_DIR) ] || mkdir -p $(DBUS_POLICY_DIR) + if INSTALL_CYGWIN_SERVICE - cp scripts/shairport-sync-dbus-policy-cygwin.conf $(DBUS_POLICY_DIR)/shairport-sync-dbus.conf +DBUS_POLICY_FILE = scripts/shairport-sync-dbus-policy-cygwin.conf else - cp scripts/shairport-sync-dbus-policy.conf $(DBUS_POLICY_DIR)/shairport-sync-dbus.conf -endif -endif +DBUS_POLICY_FILE = scripts/shairport-sync-dbus-policy.conf +endif # INSTALL_CYGWIN_SERVICE + +DBUS_POLICY_INSTALL_TARGET = dbus-policy-install-local + +$(DBUS_POLICY_INSTALL_TARGET): $(DBUS_POLICY_FILE) + install -d $(DESTDIR)$(DBUS_POLICY_DIR) + install -m 0644 $(top_srcdir)/$(DBUS_POLICY_FILE) $(DESTDIR)$(DBUS_POLICY_DIR)/shairport-sync-dbus.conf + +endif # USE_DBUS + if USE_MPRIS - [ -e $(DBUS_POLICY_DIR) ] || mkdir -p $(DBUS_POLICY_DIR) + if INSTALL_CYGWIN_SERVICE - cp scripts/shairport-sync-mpris-policy-cygwin.conf $(DBUS_POLICY_DIR)/shairport-sync-mpris.conf +MPRIS_POLICY_FILE = scripts/shairport-sync-mpris-policy-cygwin.conf else - cp scripts/shairport-sync-mpris-policy.conf $(DBUS_POLICY_DIR)/shairport-sync-mpris.conf -endif -endif -endif +MPRIS_POLICY_FILE = scripts/shairport-sync-mpris-policy.conf +endif # INSTALL_CYGWIN_SERVICE + +MPRIS_POLICY_INSTALL_TARGET = mpris-policy-install-local + +$(MPRIS_POLICY_INSTALL_TARGET): $(MPRIS_POLICY_FILE) + install -d $(DESTDIR)$(DBUS_POLICY_DIR) + install -m 0644 $(top_srcdir)/$(MPRIS_POLICY_FILE) $(DESTDIR)$(DBUS_POLICY_DIR)/shairport-sync-mpris.conf + +endif # USE_MPRIS + +endif # INSTALL_CONFIG_FILES + +INSTALL_GROUP_TARGET = install-group-local + +$(INSTALL_GROUP_TARGET): + getent group shairport-sync &>/dev/null || groupadd -r shairport-sync >/dev/null + +INSTALL_USER_TARGET = install-user-local + +$(INSTALL_USER_TARGET): $(INSTALL_GROUP_TARGET) + getent passwd shairport-sync &> /dev/null || useradd -r -M -g shairport-sync -s /usr/sbin/nologin -G audio shairport-sync >/dev/null + if INSTALL_SYSTEMV - getent group shairport-sync &>/dev/null || groupadd -r shairport-sync >/dev/null - getent passwd shairport-sync &> /dev/null || useradd -r -M -g shairport-sync -s /usr/bin/nologin -G audio shairport-sync >/dev/null - [ -e $(DESTDIR)$(sysconfdir)/init.d ] || mkdir -p $(DESTDIR)$(sysconfdir)/init.d - [ -f $(DESTDIR)$(sysconfdir)/init.d/shairport-sync ] || cp scripts/shairport-sync $(DESTDIR)$(sysconfdir)/init.d/ -endif + +INSTALL_SYSTEMV_TARGET = install-systemv-local + +$(INSTALL_SYSTEMV_TARGET): scripts/shairport-sync $(INSTALL_USER_TARGET) + install -d $(DESTDIR)$(sysconfdir)/init.d + [ -e $(DESTDIR)$(sysconfdir)/init.d/shairport-sync ] || install -m 0644 $(top_srcdir)/scripts/shairport-sync $(DESTDIR)$(sysconfdir)/init.d + +endif # INSTALL_SYSTEMV + if INSTALL_SYSTEMD - getent group shairport-sync &>/dev/null || groupadd -r shairport-sync >/dev/null - getent passwd shairport-sync &> /dev/null || useradd -r -M -g shairport-sync -s /usr/bin/nologin -G audio shairport-sync >/dev/null - [ -e $(DESTDIR)$(systemdsystemunitdir) ] || mkdir -p $(DESTDIR)$(systemdsystemunitdir) - [ -f $(DESTDIR)$(systemdsystemunitdir)/shairport-sync.service ] || cp scripts/shairport-sync.service $(DESTDIR)$(systemdsystemunitdir) -endif + +if USE_AVAHI +SYSTEMD_SERVICE = shairport-sync.service-avahi +else +SYSTEMD_SERVICE = shairport-sync.service +endif # USE_AVAHI + +INSTALL_SYSTEMD_TARGET = install-systemd-local + +$(INSTALL_SYSTEMD_TARGET): scripts/$(SYSTEMD_SERVICE) $(INSTALL_USER_TARGET) + install -d $(DESTDIR)$(systemdsystemunitdir) + [ -e $(DESTDIR)$(systemdsystemunitdir)/shairport-sync.service ] || install -m 0644 $(top_srcdir)/scripts/$(SYSTEMD_SERVICE) $(DESTDIR)$(systemdsystemunitdir)/shairport-sync.service + +endif # INSTALL_SYSTEMD + if INSTALL_FREEBSD_SERVICE - # Choose a uid and gid of 801 completely arbitrarity, except that it should be below 1000. FreeBSD doesn't seem to allow you to say "an ID in the range of..." + +# Choose a uid and gid of 801 completely arbitrarity, except that it should be below 1000. FreeBSD doesn't seem to allow you to say "an ID in the range of..." +install-freebsd-user-local: pw showgroup shairport-sync > /dev/null 2>&1 || pw addgroup -n shairport-sync -g 801 > /dev/null 2>&1 pw showuser shairport-sync > /dev/null 2>&1 || pw adduser -c "shairport-sync unprivileged user" -n shairport-sync -u 801 -s /usr/sbin/nologin -d /nonexistent > /dev/null 2>&1 - [ -e /var/run/shairport-sync ] || mkdir -p /var/run/shairport-sync - chown shairport-sync:shairport-sync /var/run/shairport-sync - [ -f /usr/local/etc/rc.d/shairport_sync ] || cp scripts/shairport-sync.freebsd /usr/local/etc/rc.d/shairport_sync - chmod 555 /usr/local/etc/rc.d/shairport_sync -endif + +INSTALL_FREEBSD_TARGET = install-freebsd-local + +$(INSTALL_FREEBSD_TARGET): scripts/shairport-sync.freebsd install-freebsd-user-local + install -d -o shairport-sync -g shairport-sync $(DESTDIR)/var/run/shairport-sync + install -d $(DESTDIR)/usr/local/etc/rc.d/ + install -m 0555 $(top_srcdir)/scripts/shairport-sync.freebsd $(DESTDIR)/usr/local/etc/rc.d/shairport_sync + +endif # INSTALL_FREEBSD_SERVICE + if INSTALL_CYGWIN_SERVICE - cp scripts/shairport-sync-config /usr/local/bin -endif + +INSTALL_CYGWIN_TARGET = install-cygwin-local + +$(INSTALL_CYGWIN_TARGET): scripts/shairport-sync-config + install -d $(DESTDIR)/usr/local/bin + [ -e $(DESTDIR)/usr/local/bin/shairport-sync-config ] || install -m 0755 $(top_srcdir)/scripts/shairport-sync-config $(DESTDIR)/usr/local/bin/ + +endif # INSTALL_CYGWIN_SERVICE + +install-exec-hook: $(CONFIG_FILE_INSTALL_TARGET) \ + $(DBUS_POLICY_INSTALL_TARGET) \ + $(MPRIS_POLICY_INSTALL_TARGET) \ + $(INSTALL_SYSTEMV_TARGET) \ + $(INSTALL_SYSTEMD_TARGET) \ + $(INSTALL_FREEBSD_TARGET) \ + $(INSTALL_CYGWIN_TARGET) diff --git a/OPENBSD.md b/OPENBSD.md index 16465e6b..c046390d 100644 --- a/OPENBSD.md +++ b/OPENBSD.md @@ -1,4 +1,4 @@ -Shairport Sync on OpenBSD +Shairport Sync on OpenBSD [AirPlay 2 Not Supported] ---- This is a note about installing Shairport Sync on OpenBSD. Shairport Sync compiles and runs natively on OpenBSD using the `sndio` back end. For general information on `sndio` please follow [this link](http://www.sndio.org). diff --git a/README.md b/README.md index e155eeb3..704c8f3e 100644 --- a/README.md +++ b/README.md @@ -1,657 +1,71 @@ +# Shairport Sync +Shairport Sync is an [AirPlay](https://www.pocket-lint.com/speakers/news/apple/144646-apple-airplay-2-vs-airplay-what-s-the-difference) audio player for Linux and FreeBSD. It plays audio streamed from Apple devices and from AirPlay sources such as [OwnTone](https://github.com/owntone/owntone-server) (formerly `forked-daapd`). -Shairport Sync -============= -Shairport Sync is an AirPlay 1 audio player. Switch to the `development` branch for a version with limited AirPlay 2 functionality. Shairport Sync plays audio streamed from iTunes, iOS, Apple TV and macOS devices and AirPlay sources such as Quicktime Player and [OwnTone](https://github.com/owntone/owntone-server#owntone-previously-forked-daapd), among others. +Shairport Sync can be built as an AirPlay 2 player (with [some limitations](https://github.com/mikebrady/shairport-sync/blob/development/AIRPLAY2.md#features-and-limitations)) or as "classic" Shairport Sync – a player for the older, but still supported, AirPlay (aka "AirPlay 1") protocol. -Audio played by a Shairport Sync-powered device stays synchronised with the source and hence with similar devices playing the same source. In this way, synchronised multi-room audio is possible for players that support it, such as iTunes and the macOS Music app. +Metadata such as artist information and cover art can be requested and provided to other applications. Shairport Sync can interface with other applications through MQTT, an MPRIS-like interface and D-Bus. -Shairport Sync runs on Linux, FreeBSD and OpenBSD. It does not support AirPlay video or photo streaming. +Shairport Sync does not support AirPlay video or photo streaming. -More Information ----------- -Shairport Sync offers *full audio synchronisation*, a feature of AirPlay that previous implementations do not provide. Full audio synchronisation means that audio is played on the output device at exactly the time specified by the audio source. To accomplish this, Shairport Sync needs access to audio systems – such as `alsa` on Linux and `sndio` on FreeBSD – that provide very accurate timing information about output devices. Shairport Sync must have direct access to the output device used, which must be a real sound card capable of working with 44,100, 88,200 or 176,400 samples per second, interleaved PCM stereo of 8, 16, 24 or 32 bits. The default is 44,100 samples per second / 16 bits (you'll get a message in the logfile if there's a problem). +# Quick Start +* A building guide is available [here](BUILD.md). +* A Docker image is available on the [Docker Hub](https://hub.docker.com/r/mikebrady/shairport-sync). +* Next Steps and Advanced Topics are [here](ADVANCED%20TOPICS/README.md). +* Runtime settings are documented [here](scripts/shairport-sync.conf). +* Build configuration options are detailed in [CONFIGURATION FLAGS.md](CONFIGURATION%20FLAGS.md). -Alternatively, Shairport Sync works well with PulseAudio, a widely used sound server found on many desktop Linuxes. While the timing information is not as accurate as that of `alsa` or `sndio`, it is often impractical to remove or disable PulseAudio. In that case, the `pa` backend can be used. An older backend for PulseAudio called `pulse` does not support synchronisation and is deprecated. +# Features +* Outputs AirPlay audio to [ALSA](https://www.alsa-project.org/wiki/Main_Page), [sndio](http://www.sndio.org), [PulseAudio](https://www.freedesktop.org/wiki/Software/PulseAudio/), [Jack Audio](http://jackaudio.org), to a unix pipe or to `STDOUT`. It also has experimental support for [PipeWire](https://pipewire.org) and limited support for [libao](https://xiph.org/ao/) and for [libsoundio](http://libsound.io). +* Metadata — Shairport Sync can deliver metadata supplied by the source, such as Album Name, Artist Name, Cover Art, etc. through a pipe or UDP socket to a recipient application program — see https://github.com/mikebrady/shairport-sync-metadata-reader for a sample recipient. Sources that supply metadata include iTunes and the Music app in macOS and iOS. +* An interface to [MQTT](https://en.wikipedia.org/wiki/MQTT), a popular protocol for Inter Process Communication, Machine-to-Machine, Internet of Things and Home Automation projects. The interface including access to metadata and artwork, and limited remote control. +* Digital Signal Processing facilities – please see the [DSP Wiki Page Guide](https://github.com/mikebrady/shairport-sync/wiki/Digital-Signal-Processing-with-Shairport-Sync). (Thanks to [Yann Pomarède](https://github.com/yannpom) for the code and to [Paul Wieland](https://github.com/PaulWieland) for the guide.) +* An [MPRIS](https://specifications.freedesktop.org/mpris-spec/2.2/)-like interface, partially complete and very functional, including access to metadata and artwork, and limited remote control. +* A native D-Bus interface, including access to metadata and artwork, limited remote control and system settings. +* Better Volume Control — Shairport Sync offers finer control at very top and very bottom of the volume range. See http://tangentsoft.net/audio/atten.html for a good discussion of audio "attenuators", upon which volume control in Shairport Sync is modelled. See also the diagram of the volume transfer function in the documents folder. In addition, Shairport Sync can offer an extended volume control range on devices with a restricted range. +* Support for the [Apple ALAC decoder](https://macosforge.github.io/alac/) (library available [here](https://github.com/mikebrady/alac)). +* Output bit depths of 8, 16, 24 and 32 bits, rather than the standard 16 bits. +* Output frame rates of 44,100, 88,200, 176,000 or 352,000 frames per second. -For other use cases, Shairport Sync can provide synchronised audio output to a unix pipe or to standard output, or to audio systems that do not provide timing information. This could perhaps be described as *partial audio synchronisation*, where synchronised audio is provided by Shairport Sync, but what happens to it in the subsequent processing chain, before it reaches the listener's ear, is outside the control of Shairport Sync. +Some features require configuration at build time – see [CONFIGURATION FLAGS.md](CONFIGURATION%20FLAGS.md). -For more about the motivation behind Shairport Sync, please see the wiki at https://github.com/mikebrady/shairport-sync/wiki. +# Status +Shairport Sync was designed to [run best](ADVANCED%20TOPICS/GetTheBest.md) on stable, dedicated, stand-alone low-power "headless" systems with ALSA as the audio system and with a decent CD-quality Digital to Analog Converter (DAC). -Synchronisation, Latency, "Stuffing" ---------- -The AirPlay protocol uses an agreed *latency* – the time difference, or delay, between the time represented by a sound sample's `timestamp` and the time it is actually played by the audio output device, typically a Digital to Audio Converter (DAC). The latency to be used is specified by the audio source when it negotiates with Shairport Sync. Most sources set a latency of two seconds. Recent versions of iTunes and forkedDaapd use a latency of just over 2.25 seconds. A latency of this length allows AirPlay players to correct for network delays, processing time variations and so on. +Shairport Sync runs on recent (2018 onwards) Linux systems and FreeBSD from 12.1 onwards. It requires a system with the power of a Raspberry Pi 2 or a Pi Zero 2 or better. -As mentioned previously, Shairport Sync implements full audio synchronisation when used with `alsa`, `sndio` or PulseAudio systems. This is done by monitoring the timestamps present in data coming from the audio source and the timing information from the audio system, e.g. `alsa`. To maintain the latency required for exact synchronisation, if the output device is running slow relative to the source, Shairport Sync will delete frames of audio to allow the device to keep up. If the output device is running fast, Shairport Sync will insert frames to keep time. The number of frames inserted or deleted is so small as to be almost inaudible on normal audio material. Frames are inserted or deleted as necessary at pseudorandom intervals. Alternatively, with `libsoxr` support, Shairport Sync can resample the audio feed to ensure the output device can keep up. This is less obtrusive than insertion and deletion but requires a good deal of processing power — most embedded devices probably can't support it. The process of insertion/deletion or resampling is rather inelegantly called “stuffing”. +Classic Shairport Sync runs on a wider variety of Linux sytems, including OpenWrt and Cygwin and it also runs on OpenBSD. Many embedded devices are powerful enough to power classic Shairport Sync. + +# Heritage and Acknowledgements +The functionality offered by Shairport Sync is the result of study and analysis of the AirPlay and AirPlay 2 protocols by many people over the years. These protocols have not been officially published, and there is no assurance that Shairport Sync will continue to work in future. + +Shairport Sync is a substantial rewrite of the fantastic work done in Shairport 1.0 by James Wah (aka [abrasive](https://github.com/abrasive)), James Laird and others — please see [this list](https://github.com/abrasive/shairport/blob/master/README.md#contributors-to-version-1x) of the contributors to Shairport 1.x and Shairport 0.x. From a "heritage" point of view, Shairport Sync is a fork of Shairport 1.0. + +For the development of AirPlay 2 support, special thanks are due to: +* [JD Smith](https://github.com/jdtsmith) for really thorough testing, support and encouragement. +* [ejurgensen](https://github.com/ejurgensen) for advice and [code to deal with pairing and encryption](https://github.com/ejurgensen/pair_ap). +* [ckdo](https://github.com/ckdo) for pointing the way, particularly with pairing and encryption protocols, with a [functional Python implementation](https://github.com/ckdo/airplay2-receiver) of AirPlay 2. +* [invano](https://github.com/invano) for showing what might be possible and for initial Python development. +* [Charles Omer](https://github.com/charlesomer) for Docker automation, repository management automation, testing, encouragement, enthusiasm. + +Much of Shairport Sync's AirPlay 2 functionality is based on ideas developed at the [openairplay airplay2-receiver]( https://github.com/openairplay/airplay2-receiver) repository. It is a pleasure to acknowledge the work of the contributors there. + +Thanks to everyone who has supported and improved Shairport Sync over the years. + +# More about Shairport Sync +The audio that Shairport Sync receives is sent to the computer's sound system, to a named unix pipe or to `STDOUT`. By far the best sound system to use is ALSA. This is because ALSA can give direct access to the Digital to Analog Converter (DAC) hardware of the machine. Audio samples can be sent through ALSA directly to the DAC, maximising fidelity, and accurate timing information can be obtained from the DAC, maximising synchronisation. Direct access to hardware is given through ALSA devices with names beginning with `hw:`. + +## Synchronised Audio +Shairport Sync offers *full audio synchronisation*. Full audio synchronisation means that audio is played on the output device at exactly the time specified by the audio source. To accomplish this, Shairport Sync needs access to audio systems – such as ALSA on Linux and `sndio` on FreeBSD – that provide very accurate timing information about audio being streamed to output devices. Ideally, Shairport Sync should have direct access to the output device used, which should be a real sound card capable of working with 44,100, 88,200 or 176,400 samples per second, interleaved PCM stereo of 8, 16, 24 or 32 bits. Using the ALSA sound system, Shairport Sync will choose the greatest bit depth available at 44,100 samples per second, resorting to multiples of 44,100 if it is not available. You'll get a message in the log if there's a problem. With all other sound systems, a sample rate of 44,100 is chosen with a bit depth of 16 bit. + +Shairport Sync works well with PulseAudio, a widely used sound server found on many desktop Linuxes. While the timing information is not as accurate as that of ALSA or `sndio`, it is often impractical to remove or disable PulseAudio. + +For other use cases, Shairport Sync can provide synchronised audio output to a unix pipe or to `STDOUT`, or to audio systems that do not provide timing information. This could perhaps be described as *partial audio synchronisation*, where synchronised audio is provided by Shairport Sync, but what happens to it in the subsequent processing chain, before it reaches the listener's ear, is outside the control of Shairport Sync. + +## Latency, "Stuffing", Timing +AirPlay protocols use an agreed *latency* – a time lag or delay – between the time represented by a sound sample's `timestamp` and the time it is actually played by the audio output device, typically a Digital to Audio Converter (DAC). Latency gives players time to compensate for network delays, processing time variations and so on. The latency is specified by the audio source when it negotiates with Shairport Sync. AirPlay sources set a latency of around 2.0 to 2.25 seconds. AirPlay 2 can use shorter latencies, around half a second. + +As mentioned previously, Shairport Sync implements full audio synchronisation when used with ALSA, `sndio` or PulseAudio audio systems. This is done by monitoring the timestamps present in data coming from the audio source and the timing information coming back from the audio system itself. To maintain the latency required for exact synchronisation, if the output device is running slow relative to the source, Shairport Sync will delete frames of audio to allow the device to keep up. If the output device is running fast, Shairport Sync will insert ("stuff") extra frames to keep time. The number of frames inserted or deleted is so small as to be almost inaudible on normal audio material. Frames are inserted or deleted as necessary at pseudorandom intervals. Alternatively, with `libsoxr` support, Shairport Sync can resample the audio feed to ensure the output device can keep up. This is less obtrusive than insertion and deletion but requires a good deal of processing power — most embedded devices probably can't support it. If your computer is fast enough, Shairport Sync will, by default, automatically choose this method. Stuffing is not done for partial audio synchronisation – the audio samples are simply presented at exactly the right time to the next stage in the processing chain. -Timestamps are referenced relative to the source computer's clock – the `source clock`, but timing must be done relative to the clock of the computer running Shairport Sync – the `local clock`. So, another thing Shairport Sync has to do is to synchronize the source clock and the local clock, and it does this usually to within a fraction of a millisecond, using a variant of NTP synchronisation protocols. - -What else? --------------- -* Better Volume Control — Shairport Sync offers finer control at very top and very bottom of the volume range. See http://tangentsoft.net/audio/atten.html for a good discussion of audio "attenuators", upon which volume control in Shairport Sync is modelled. See also the diagram of the volume transfer function in the documents folder. In addition, Shairport Sync can offer an extended volume control range on devices with a restricted range. -* Hardware Mute — Shairport Sync can mute properly if the hardware supports it. -* Support for the Apple ALAC decoder. -* Output bit depths of 8, 16, 24 and 32 bits, rather than the standard 16 bits. -* Output frame rates of 44,100, 88,200, 176,000 or 352,000 frames per second. -* Fast Response — With hardware volume control, response is instantaneous; otherwise the response time is 0.20 seconds with `alsa`, 0.35 seconds with `sndio`. -* Non-Interruptible — Shairport Sync sends back a "busy" signal if it's already playing audio from another source, so other sources can't disrupt an existing Shairport Sync session. (If a source disappears without warning, the session automatically terminates after two minutes and the device becomes available again.) -* Metadata — Shairport Sync can deliver metadata supplied by the source, such as Album Name, Artist Name, Cover Art, etc. through a pipe or UDP socket to a recipient application program — see https://github.com/mikebrady/shairport-sync-metadata-reader for a sample recipient. Sources that supply metadata include iTunes and the Music app in macOS and iOS. -* Compiles on Linux, Cygwin, FreeBSD, OpenBSD. -* Outputs to [`alsa`](https://www.alsa-project.org/wiki/Main_Page), [`sndio`](http://www.sndio.org), [PulseAudio](https://www.freedesktop.org/wiki/Software/PulseAudio/), [JACK](http://jackaudio.org), to a unix pipe or to `STDOUT`. It also has limited support for [libao](https://xiph.org/ao/) and for [`soundio`](http://libsound.io). -* An [MPRIS](https://specifications.freedesktop.org/mpris-spec/2.2/) interface, partially complete and very functional, including access to metadata and artwork, and some limited remote control. -* An interface to [MQTT](https://en.wikipedia.org/wiki/MQTT), an often-used protocol in home automation projects. -* A native D-Bus interface, including access to metadata and artwork, some limited remote control and some system settings. -* Digital Signal Processing facilities -- please see the [DSP Wiki Page Guide](https://github.com/mikebrady/shairport-sync/wiki/Digital-Signal-Processing-with-Shairport-Sync). (Thanks to [Yann Pomarède](https://github.com/yannpom) for the code and to [Paul Wieland](https://github.com/PaulWieland) for the guide.) - -Heritage -------- -Shairport Sync is a substantial rewrite of the fantastic work done in Shairport 1.0 by James Laird and others — please see https://github.com/abrasive/shairport/blob/master/README.md#contributors-to-version-1x for a list of the contributors to Shairport 1.x and Shairport 0.x. From a "heritage" point of view, Shairport Sync is a fork of Shairport 1.0. - -Status ------- -Shairport Sync works on a wide variety of Linux devices, FreeBSD and OpenBSD. It works with built-in audio and with a variety of USB-connected audio amplifiers and DACs. Shairport Sync runs well on the Raspberry Pi. It can drive the built-in sound card – see the note below on configuring the Raspberry Pi to make best use of it. It runs well on the Raspberry Pi Zero W with a suitable USB or I2S card. - -Shairport Sync will work with PulseAudio, which is installed in many desktop Linuxes. PulseAudio normally runs in the *user mode* but can be configured to run in *system mode*, though this is not recommended. Shairport Sync can work with it in either mode. - -Shairport Sync runs natively on FreeBSD and OpenBSD using the `sndio` sound system. - -Shairport Sync runs on Ubuntu, OpenWrt, Debian, Arch Linux, Fedora, FreeBSD and OpenBSD inside VMWare Fusion on a Mac, but synchronisation is inaccurate — possibly because the sound card is being emulated. - -For information about changes and updates, please refer to the RELEASENOTES.md file in the distribution. - -Building And Installing ---------------------- -See [here](https://github.com/mikebrady/shairport-sync/blob/master/INSTALL.md) for simple installation instructions for modern Linux systems like Rapsberry Pis. - -**Docker:** Shairport Sync is available as a prebuilt Docker image at https://hub.docker.com/r/mikebrady/shairport-sync. Alternatively, you can roll your own using the Dockerfile provided. Note that, at present, the Shairport Sync Docker image does not work on a Mac, due to limitations in the Docker system. - -Shairport Sync may already be available as a package in your Linux distribution (search for `shairport-sync` – the package named `shairport` is a different program). Packages are available on recent versions of Debian, Ubuntu, Arch, OpenWrt and possibly more: - -**Ubuntu:** A `shairport-sync` installer package is available for Ubuntu. Additionally, a Personal Package Archives for Shairport Sync master and development branches are available at https://launchpad.net/~dantheperson. - -**Debian:** shairport-sync is in the Debian archive. - -**Ansible Playbooks for CentOS 8 Stream on Raspberry Pi:** A suite of Ansible playbooks and scripts to make deploying Shairport Sync easy on CentOS 8 Stream specifically on Raspberry Pi is available at https://github.com/p3ck/ansible-shairport. - -**OpenWrt:** There is a Shairport Sync package in OpenWrt trunk. Also, there's an OpenWrt package at https://github.com/mikebrady/shairport-sync-for-openwrt, including one that builds back to Barrier Breaker. - -**Arch Linux:** Shairport Sync is available for x86_64 and i686 platforms in the Arch Linux Community Repository -- search for `shairport-sync`. See also https://www.archlinux.org/packages/. - -To build and install the latest version of Shairport Sync, an [Arch Linux build and installation guide](https://github.com/mikebrady/shairport-sync-for-arch-linux) is available, based on original work by [Elia Cereda](https://github.com/EliaCereda). - -**Mac OS X:** A HomeBrew package exists for Shairport Sync. With HomeBrew installed, Shairport Sync can be installed using the command: -``` -$brew install shairport-sync -``` -Note that the installation uses the libao library and so synchronisation is not available — playback glitches will occur occasionally, when the ao system's buffers overflow or underflow. - -**Fedora:** Please see the guide at [FEDORA.md](https://github.com/mikebrady/shairport-sync/blob/master/FEDORA.md). - -**Gentoo:** Shairport Sync is available in griffon_overlay, please see the guide at [https://github.com/windfail/griffon_overlay/wiki/shairport-sync](https://github.com/windfail/griffon_overlay/wiki/shairport-sync). - -**Cygwin:** Please see the guide at [CYGWIN.md](https://github.com/mikebrady/shairport-sync/blob/master/CYGWIN.md). - -**OpenBSD:** A port exists for Shairport Sync. Packages are available for users of -current OpenBSD, the first release to include this port will be OpenBSD 7.2. To install, simply run - -``` -pkg_add shairport_sync -``` -Configure your system to start the service at boot time with -``` -rcctl enable messagebus avahi_daemon shairport_sync -``` - -Note that the README for this port includes instructions on how to share access to the audio device between Shairport Sync and another user. - -Sincere thanks to all package contributors! - -If you wish to build and install the latest version of Shairport Sync on Debian, Ubuntu, Fedora or Arch platforms, please continue to follow these instructions. When the program has been compiled and installed, refer to the section on Configuring Shairport Sync that follows. To build Shairport Sync from sources on FreeBSD please refer to [FREEBSD.md](https://github.com/mikebrady/shairport-sync/blob/master/FREEBSD.md). - -**Remove Old Versions of Shairport Sync and its Startup Scripts** - -You should check to see if `shairport-sync` is already installed – you can use the command `$ which shairport-sync` to find where it is located, if installed. If it is installed you should delete it – you may need superuser privileges. After deleting, check again in case further copies are installed elsewhere. - -You should also remove the startup script and service definition files `/etc/systemd/system/shairport-sync.service`, `/lib/systemd/system/shairport-sync.service`, `/etc/init.d/shairport-sync`, `/etc/dbus-1/system.d/shairport-sync-dbus.conf` and `/etc/dbus-1/system.d/shairport-sync-mpris.conf` if they exist – new ones will be installed if necessary. - -If you removed any installations of Shairport Sync or any of its startup script files, you should reboot. - -**Determine The Configuration Needed** - -Shairport Sync has a number of different "backends" that connect it to the system's audio handling infrastructure. Most recent Linux distributions that have a GUI – including Ubuntu, Debian and others – use PulseAudio to handle sound. In such cases, it is inadvisable to attempt to disable or remove PulseAudio. Thus, if your system uses PulseAudio, you should build Shairport Sync with the PulseAudio backend. You can check to see if PulseAudio is running by opening a Terminal window and entering the command `$ pactl info`. Here is an example of what you'll get if PulseAudio is installed, though the exact details may vary: -``` -$ pactl info -Server String: unix:/run/user/1000/pulse/native -Library Protocol Version: 30 -Server Protocol Version: 30 -Is Local: yes -Client Index: 9 -Tile Size: 65472 -User Name: mike -Host Name: ubuntu -Server Name: pulseaudio -Server Version: 8.0 -Default Sample Specification: s16le 2ch 44100Hz -Default Channel Map: front-left,front-right -Default Sink: alsa_output.pci-0000_02_02.0.analog-stereo -Default Source: alsa_input.pci-0000_02_02.0.analog-stereo -Cookie: 96f9:3e8d -$ -``` -If PulseAudio in not installed, you'll get something like this: -``` -$ pactl info --bash: pactl: command not found -$ -``` -If your system does not use PulseAudio, then it is likely that it uses the Advanced Linux Sound Architecture (ALSA), so you should build Shairport Sync with the ALSA backend. By the way, many systems with PulseAudio also have ALSA (in fact, PulseAudio is effectively a client of ALSA); in those cases you should choose the PulseAudio backend. - -If PulseAudio is not installed, there is no necessity to install it for Shairport Sync. In fact, Shairport Sync works better without it. - -**Building** - -To build Shairport Sync from sources on Debian, Ubuntu, Raspbian, etc. follow these instructions. - -The following libraries are required: -* OpenSSL or mbed TLS (PolarSSL is supported but deprecated) -* Avahi -* ALSA and/or PulseAudio -* libdaemon -* autoconf -* automake -* libtool -* libpopt -* libconfig - -Optional: -* libsoxr -* libalac (This is a library containing the Apple ALAC decoder.) - -Many Linux distributions have Avahi and OpenSSL already in place, so normally it probably makes sense to choose those options rather than tinysvcmdns or mbed TLS. The `libsoxr` library is available in recent Linux distributions, but it requires lots of processor power. - -Debian, Ubuntu and Raspbian users can get the basics with: - -- `# apt install build-essential git xmltoman` – these may already be installed. -- `# apt install autoconf automake libtool libdaemon-dev libpopt-dev libconfig-dev` -- `# apt install libasound2-dev` for the ALSA libraries -- `# apt install libpulse-dev` for the PulseAudio libraries -- `# apt install avahi-daemon libavahi-client-dev` if you want to use Avahi (recommended). -- `# apt install libssl-dev` if you want to use OpenSSL and libcrypto, or use mbed TLS otherwise. -- `# apt install libmbedtls-dev` if you want to use mbed TLS, or use OpenSSL/libcrypto otherwise. You can still use PolarSSL with `apt install libpolarssl-dev` if you want to use PolarSSL, but it is deprecated as it's not longer being supported. -- `# apt install libsoxr-dev` if you want support for libsoxr-based resampling. This library is in recent distributions; if not, instructions for how to build it from source on Linux are available at [LIBSOXR.md](https://github.com/mikebrady/shairport-sync/blob/master/LIBSOXR.md). -- `# apt install libsndfile1-dev` if you want to use the convolution filter. - -If you wish to include the Apple ALAC decoder, you need install it first – please refer to the [ALAC](https://github.com/mikebrady/alac) repository for more information. - -**Download Shairport Sync:** -``` -$ git clone https://github.com/mikebrady/shairport-sync.git -``` - -Next, `cd` into the shairport-sync directory and execute the following commands: -``` -$ autoreconf -i -f -``` -(Note that the `autoreconf...` step may take some time on less powerful machines.) - -**Choose the appropriate `--with-*` options:** - -(Don't worry -- there's a recommended set of configuration options further down.) - -- `--with-alsa` include the ALSA backend module to audio to be output through the Advanced Linux Sound Architecture (ALSA) system directly. This is recommended for highest quality. -- `--with-pa` include the PulseAudio audio back end. This is recommended if your Linux installation already has PulseAudio installed. Although ALSA would be better, it requires direct and exclusive access to to a real (hardware) soundcard, and this is often impractical if PulseAudio is installed. -- `--with-stdout` include an optional backend module to enable raw audio to be output through standard output (stdout). -- `--with-pipe` include an optional backend module to enable raw audio to be output through a unix pipe. -- `--with-soundio` include an optional backend module to enable raw audio to be output through the soundio system. -- `--with-avahi` or `--with-tinysvcmdns` for mdns support. Avahi is a widely-used system-wide zero-configuration networking (zeroconf) service — it may already be in your system. If you don't have Avahi, or similar, then consider including tinysvcmdns, which is a tiny zeroconf service embedded inside the shairport-sync application itself. To enable multicast for `tinysvcmdns`, you may have to add a default route with the following command: `route add -net 224.0.0.0 netmask 224.0.0.0 eth0` (substitute the correct network port for `eth0`). You should not have more than one zeroconf service on the same system — bad things may happen, according to RFC 6762, §15. If you need to use an external zeroconf service (`--with-external-mdns`) to avoid this problem, you may need to install avahi-utils or avahi-tools to get the `avahi-publish-service` tool for your system. -- `--with-ssl=openssl`, `--with-ssl=mbedtls` or `--with-ssl=polarssl` (deprecated) for encryption and related utilities using either OpenSSL, mbed TLS or PolarSSL. -- `--with-libdaemon` include a demonising library needed if you want to be able to demonise Shairport Sync with the `-d` option. Not needed for `systemd`-based systems which demonise programs differently. -- `--with-soxr` for libsoxr-based resampling. -- `--with-piddir` for specifying where the PID file should be stored. This directory is normally chosen automatically. The directory must be writable. If you use this option, you may have to edit the init script to search for the PID file in your new location. -- `--with-metadata` to add support for Shairport Sync to pipe metadata to a compatible application of your choice. See https://github.com/mikebrady/shairport-sync-metadata-reader for a sample metadata reader. -- `--with-configfiles` to install a configuration file and a separate sample file at the `make install` stage. Default is to install. An existing `/etc/shairport-sync.conf` will not be overwritten. -- `--with-pkg-config` to use pkg-config to find libraries. Default is to use pkg-config — this option is for special purpose use. -- `--with-apple-alac` to include the Apple ALAC Decoder. -- `--with-convolution` to include a convolution filter that can be used to apply effects such as frequency and phase correction, and a loudness filter that compensates for human ear non-linearity. Requires `libsndfile`. -- `--with-systemd` to include a script to create a Shairport Sync service that can optionally launch automatically at startup on `systemd`-based Linuxes. Default is not to to install. -- `--with-systemv` to include a script to create a Shairport Sync service that can optionally launch automatically at startup on System V based Linuxes. Default is not to to install. - -**Determine if it's a `systemd` or a "System V" installation:** - -If you wish to have Shairport Sync start automatically when your system boots, you need to figure out what so-called "init system" your system is using. (If you are using Shairport Sync with PulseAudio, as installed in many desktop systems, this section doesn't apply.) - -There are a number of init systems in use: `systemd`, `upstart` and "System V" among others, and it's actually difficult to be certain which one your system is using. Fortunately, for Shairport Sync, all you have to do is figure out if it's a `systemd` init system or not. If it is not a `systemd` init system, you can assume that it is either a System V init system or else it is compatible with a System V init system. Recent systems tend to use `systemd`, whereas older systems use `upstart` or the earlier System V init system. - -The easiest way is to look at the first few lines of the `init` manual. Enter the command: - -``` -$ man init -``` -In a `systemd` system, the top lines of the `man` page make it clear that it's a `systemd` system, as follows (from Ubuntu 16.04): -``` -SYSTEMD(1) systemd SYSTEMD(1) - -NAME - systemd, init - systemd system and service manager -... -``` -Other init systems will look considerably different. For instance, in an `upstart` system, the top lines of the `man` page indicate it's using `upstart` system, as follows (from Ubuntu 14.04): - -``` -init(8) System Manager's Manual init(8) - -NAME - init - Upstart process management daemon - -SYNOPSIS - init [OPTION]... -... -``` -In a System V system, the top lines of the `man` page are as follows (from Debian 7.11): -``` -INIT(8) Linux System Administrator's Manual INIT(8) - -NAME - init, telinit - process control initialization - -SYNOPSIS - /sbin/init [ -a ] [ -s ] [ -b ] [ -z xxx ] [ 0123456Ss ] - /sbin/telinit [ -t SECONDS ] [ 0123456sSQqabcUu ] - /sbin/telinit [ -e VAR[=VAL] ] - -... -``` -If your system is definitely a `systemd` system, choose `--with-systemd` below. Otherwise, choose `--with-libdaemon --with-systemv`. - -**Choose the location of the configuration file** - -A final consideration is the location of the configuration file `shairport-sync.conf`. This will be placed in the directory specified by the `sysconfdir` configuration variable, which defaults to `/usr/local/etc`. This is normal in BSD Unixes, but is unusual in Linux. Hence, for Linux installations, you need to set the `sysconfdir` variable to `/etc` using the configuration setting `--sysconfdir=/etc`. - -**Sample `./configure` command with parameters for a typical Linux `systemd` installation:** - -Here is a recommended set of configuration options suitable for Linux installations that use `systemd`, such as Ubuntu 15.10 and later, and Raspbian Buster, Stretch and Jessie. It specifies both the ALSA and PulseAudio backends and includes a sample configuration file and an script for automatic startup on system boot: - -`$ ./configure --sysconfdir=/etc --with-alsa --with-pa --with-avahi --with-ssl=openssl --with-metadata --with-soxr --with-systemd` - -* Omit the `--with-soxr` if the libsoxr library is not available. -* For installation into a System V system, replace the `--with-systemd` with `--with-libdaemon --with-systemv`. -* If you intend to use Shairport Sync with PulseAudio in the standard user mode, it can not be a system service, so you should omit both `--with-systemd` and `--with-systemv`. - -**Build and Install the Application:** - -Enter: - -``` -$ make -``` - -to build the application. - -Assuming you have used the `./configure` settings suggested above, you can now install the application: - -``` -$ sudo make install -``` -The user and group `shairport-sync` will be created if necessary, and a runtime folder will be created at `/var/run/shairport-sync` if you have chosen `--with-systemv`. In addition, a `man` page, a default configuration file and automatic power-on startup script will be installed. - - -**Complete installation into to a `systemd` system** - -If you have chosen the `--with-systemd` configuration option, then, to enable Shairport Sync to start automatically at system startup, enter: - -``` -$ sudo systemctl enable shairport-sync -``` -You should then reboot the system. - -**Complete installation into a System V system** - -If you have chosen the `--with-systemv` configuration option, then, to enable Shairport Sync to start automatically at system startup, enter: -``` -$ sudo update-rc.d shairport-sync defaults 90 10 -$ sudo update-rc.d shairport-sync enable -``` -You should then reboot the system. - -**Man Page** - -You can view the man page here: http://htmlpreview.github.io/?https://github.com/mikebrady/shairport-sync/blob/master/man/shairport-sync.html - -Configuring Shairport Sync --------- -There are two logically distinct parts to getting Shairport Sync to run properly on your machine: (1) starting and stopping it and (2) ensuring it has the right settings. - -**(1) Starting and Stopping:** -Starting and stopping Shairport Sync automatically is taken care of differently in different versions of Linux – see the previous section for an example of installing into a `systemd` or a System V based system. - -If you are using PulseAudio in the standard "user" mode, you can not start Shairport Sync automatically at boot time – it must be started when the user logs in to a GUI session. Various GUI tools exist to enable you to build a Startup Application. However, there does not appear to be a similar tool for terminating the program when you log out. Also, if the GUI switches to another user, the user's PulseAudio session is disconnected from the output device. - -**(2) Settings:** -To get the best from Shairport Sync, you’ll need to (a) give Shairport Sync a service name by which it will be seen in iTunes etc. and (b) specify the backend you wish to use - `alsa` for the ALSA backend, or `pa` for the PulseAudio back end. If only one backend is included at compilation, or if the backend is ALSA, there is no need to explicitly specify the backend. - -For the ALSA backend you may need to (c) specify the output device to use and (d) specify the name of the mixer volume control to use to control the output level. To get values for (c) and (d) you might need to explore the ALSA output devices with a program like `alsamixer` or similar. - -Shairport Sync reads settings from a configuration file at `/etc/shairport-sync.conf` (note that in FreeBSD it will be at `/usr/local/etc/shairport-sync.conf`). When you run `$sudo make install`, a sample configuration file is installed or updated at `/etc/shairport-sync.conf.sample` (`/usr/local/etc/shairport-sync.conf.sample` in FreeBSD). This contains all the setting groups and all the settings available, but they all are commented out (comments begin with `//`) so that default values are used. The file contains explanations of the settings, useful hints and suggestions. In addition, if the file doesn't already exist, a default configuration is installed, which should work in almost any system with a sound card. - -Settings in the configuration file are grouped. For instance, there is a `general` group within which you can use the `name` tag to set the service name. Suppose you wanted to set the name of the service to `Front Room` and give the service the password `secret`, then you should do the following: - -``` -general = -{ - name = "Front Room"; - password = "secret"; - // ... other general settings -}; -``` -(Remember, anything preceded by `//` is a comment and will have no effect on the setting of Shairport Sync.) - -**Important:** You should *never* use an important password as the AirPlay password for a Shairport Sync player -- the password is stored in Shairport Sync's configuration file in plain text and is thus completely vulnerable. - -No backend is specified here, so it will default to the `alsa` backend if more than one back end has been compiled. To route the output to PulseAudio, add: - -``` - output_backend = "pa"; -``` -to the `general` group. - -The `alsa` group is used to specify properties of the output device. The most obvious setting is the name of the output device which you can set using the `output_device` tag. - -The following `alsa` group settings are very important for maximum performance. If your audio device has a mixer that can be use to control the volume, then Shairport Sync can use it to give instant response to volume and mute commands and it can offload some work from the processor. -* The `mixer_control_name` tag allows you to specify the name of the mixer volume control. -* The `mixer_device` tag allows you specify where the mixer is. By default, the mixer is on the `output_device`, so you only need to use the `mixer_device` tag if the mixer is elsewhere. This can happen if you specify a *device* rather than a *card* with the `output_device` tag, because normally a mixer is associated with a *card* rather than a device. Suppose you wish to use the output device `5` of card `hw:0` and the mixer volume-control named `PCM`: - -``` -alsa = -{ - output_device = "hw:0,5"; - mixer_device = "hw:0"; - mixer_control_name = "PCM"; - // ... other alsa settings -}; -``` - -The `pa` group is used to specify settings relevant to the PulseAudio backend. You can set the "Application Name" that will appear in the "Sound" control panel. - -Shairport Sync can run programs just before it starts to play an audio stream and just after it finishes. You specify them using the `sessioncontrol` group settings `run_this_before_play_begins` and `run_this_after_play_ends`. This is to facilitate situations where something has to be done before and after playing, e.g. switching on an amplifier beforehand and switching it off afterwards. Set the `wait_for_completion` value to `"yes"` for Shairport Sync to wait until the respective commands have been completed before continuing. - -Note that the full path to the programs must be specified, and script files will not be executed unless they are marked as executable and have the appropriate shebang `#!/bin/...` as the first line. (This behaviour may be different from other Shairports.) - -Shairport Sync can run a program whenever the volume is set or changed. You specify it using the `general` group setting `run_this_when_volume_changes`. This is to facilitate situations where something has to be done when the volume changes, e.g. adjust an external mixer value. Set the `wait_for_completion` value to `"yes"` for Shairport Sync to wait until the command has been completed before continuing. Again, please note that the full path to the program must be specified, and script files will not be executed unless they are marked as executable and have the appropriate shebang `#!/bin/...` as the first line. - -Note: Shairport Sync can take configuration settings from command line options. This is mainly for backward compatibility, but sometimes still useful. For normal use, it is strongly recommended that you use the configuration file method. - -**Raspberry Pi** - -The Raspberry Pi Models A and B have a built-in audio DAC that is connected to the device's headphone jack. Apart from a loud click when used for the first time after power-up, it is now quite adequate for casual listening. - -To get the benefits of improvements in the Pi's software and firmware, you should update to the Raspian release of October 2018 or later, as a number of improvements have been made to the built-in DAC. - -Do the usual update and upgrade: -``` -# apt update -# apt upgrade -``` -To make Shairport Sync output to the built-in audio DAC and use its hardware mixer, in the `alsa` section of the configuration file, set the output device and mixer as follows: -``` -alsa = -{ - output_device = "hw:0"; // the name of the alsa output device. Use "alsamixer" or "aplay" to find out the names of devices, mixers, etc. - mixer_control_name = "PCM"; // the name of the mixer to use to adjust output volume. If not specified, volume in adjusted in software. - // ... other alsa settings -``` -(Remember to uncomment the lines by removing the `//` at the start of each.) When these changes have been made, reboot the machine. - -A problem with the built-in DAC that it declares itself to have a very large mixer volume control range – all the way from -102.38dB up to +4dB, a range of 106.38 dB. In reality, only the top 60 dB of it is in any way usable. To help get the most from it, consider using the `volume_range_db` setting in the `general` group to instruct Shairport Sync to use the top of the DAC mixer's declared range. For example, if you set the `volume_range_db` figure to 60, the top 60 dB of the range will the used. With this setting on the Raspberry Pi, maximum volume will be +4dB and minimum volume will be -56dB, below which muting will occur. - -From a user's point of view, the effect of using this setting is to move the minimum usable volume all the way down to the bottom of the user's volume control, rather than have the minimum usable volume concentrated very close to the maximum volume. - -*Command Line Arguments* - -As previously mentioned, you can use command line arguments to provide settings to Shairport Sync as before, though newer settings will only be available via the configuration file. For full information, please read the Shairport Sync `man` page, also available at http://htmlpreview.github.io/?https://github.com/mikebrady/shairport-sync/blob/master/man/shairport-sync.html. - -Apart from the following options, all command line options can be replaced by settings in the configuration file. Here is a brief description of command line options that are not replicated by settings in the settings file. - -* The `-c` option allows you to specify the location of the configuration file. -* The `-V` option gives you version information about Shairport Sync and then quits. -* The `-d` option causes Shairport Sync to properly daemonise itself, that is, to run in the background. You may need sudo privileges for this. -* The `-k` option causes Shairport Sync to kill an existing Shairport Sync daemon. You may need to have sudo privileges for this. - -The System V init script at `/etc/init.d/shairport-sync` has a bare minimum : -`-d`. Basically all it does is put the program in daemon mode. The program will read its settings from the configuration file. - -Examples --------- - -Here are some examples of complete configuration files. - -``` -general = { - name = "Joe's Stereo"; -}; - -alsa = { - output_device = "hw:0"; -}; -``` - -This gives the service a particular name — "Joe's Stereo" and specifies that audio device hw:0 be used. - -For best results with the `alsa` backend — including getting true mute and instant response to volume control and pause commands — you should access the hardware volume controls. Use `amixer` or `alsamixer` or similar to discover the name of the mixer control to be used as the `mixer_control_name`. - -Here is an example for for a Raspberry Pi using its internal soundcard — device hw:0 — that drives the headphone jack: -``` -general = { - name = "Mike's Boombox"; -}; - -alsa = { - output_device = "hw:0"; - mixer_control_name = "PCM"; -}; -``` - -Here is an example of driving a Topping TP30 Digital Amplifier, which has an integrated USB DAC and which is connected as audio device `hw:1`: -``` -general = { - name = "Kitchen"; -}; - -alsa = { - output_device = "hw:1"; - mixer_control_name = "PCM"; -}; -``` - -For a cheapo "3D Sound" USB card (Stereo output and input only) on a Raspberry Pi: -``` -general = { - name = "Front Room"; -}; - -alsa = { - output_device = "hw:1"; - mixer_control_name = "Speaker"; -}; -``` - -For a first generation Griffin iMic on a Raspberry Pi: -``` -general = { - name = "Attic"; -}; - -alsa = { - output_device = "hw:1"; - mixer_control_name = "PCM"; -}; -``` - -For an NSLU2, which has no internal sound card, there appears to be a bug in ALSA — you can not specify a device other than "default". Thus: - -On an NSLU2, to drive a first generation Griffin iMic: -``` -general = { - name = "Den"; -}; - -alsa = { - mixer_control_name = "PCM"; -}; -``` - -On an NSLU2, to drive the "3D Sound" USB card: -``` -general = { - name = "TV Room"; -}; - -alsa = { - mixer_control_name = "Speaker"; -}; -``` - -Finally, here is an example of using the PulseAudio backend: -``` -general = { - name = "Zoe's Computer"; - output_backend = "pa"; -}; - -``` - - -Metadata --------- - -Shairport Sync can deliver metadata supplied by the source, such as Album Name, Artist Name, Cover Art, etc. through a pipe or UDP socket to a recipient application program — see https://github.com/mikebrady/shairport-sync-metadata-reader for a sample recipient. Sources that supply metadata include iTunes and the Music app in macOS and iOS. - -**Metadata broadcasting over UDP** - -As an alternative to sending metadata to a pipe, the `socket_address` and `socket_port` tags may be set in the metadata group to cause Shairport Sync to broadcast UDP packets containing the track metadata. - -The advantage of UDP is that packets can be sent to a single listener or, if a multicast address is used, to multiple listeners. It also allows metadata to be routed to a different host. However UDP has a maximum packet size of about 65000 bytes; while large enough for most data, Cover Art will often exceed this value. Any metadata exceeding this limit will not be sent over the socket interface. The maximum packet size may be set with the `socket_msglength` tag to any value between 500 and 65000 to control this - lower values may be used to ensure that each UDP packet is sent in a single network frame. The default is 500. Other than this restriction, metadata sent over the socket interface is identical to metadata sent over the pipe interface. - -The UDP metadata format is very simple - the first four bytes are the metadata *type*, and the next four bytes are the metadata *code* (both are sent in network byte order - see https://github.com/mikebrady/shairport-sync-metadata-reader for a definition of those terms). The remaining bytes of the packet, if any, make up the raw value of the metadata. - -Latency -------- -Latency is the exact time from a sound signal's original timestamp until that signal actually "appears" on the output of the audio output device, usually a Digital to Audio Converter (DAC), irrespective of any internal delays, processing times, etc. in the computer. - -Shairport Sync uses latencies supplied by the source, typically either 2 seconds or just over 2.25 seconds. You shouldn't need to change them. - -Problems can arise when you are trying to synchronise with speaker systems — typically surround-sound home theatre systems — that have their own inherent delays. You can compensate for an inherent delay using the appropriate backend (typically `alsa`) `audio_backend_latency_offset_in_seconds`. Set this offset (in frames) to compensate for a fixed delay in the audio back end; for example, if the output device delays by 100 ms, set this to -0.1. - -Resynchronisation -------------- -Shairport Sync actively maintains synchronisation with the source. -If synchronisation is lost — say due to a busy source or a congested network — Shairport Sync will mute its output and resynchronise. The loss-of-sync threshold is a very conservative 0.050 seconds — i.e. the actual time and the expected time must differ by more than 50 ms to trigger a resynchronisation. Smaller disparities are corrected by insertions or deletions, as described above. -* You can vary the resync threshold, or turn resync off completely, with the `general` `resync_threshold_in_seconds` setting. - -Tolerance ---------- -Playback synchronisation is allowed to wander — to "drift" — a small amount before attempting to correct it. The default is 0.002 seconds, i.e. 2 ms. The smaller the tolerance, the more likely it is that overcorrection will occur. Overcorrection is when more corrections (insertions and deletions) are made than are strictly necessary to keep the stream in sync. Use the `statistics` setting to monitor correction levels. Corrections should not greatly exceed net corrections. -* You can vary the tolerance with the `general` `drift_tolerance_in_seconds` setting. - -Some Statistics ---------------- -If you turn on the `general` `statistics` setting, a heading like this will be output to the log file (or to `STDERR` if the `-u` command line option is chosen): -``` -sync error in milliseconds, net correction in ppm, corrections in ppm, total packets, missing packets, late packets, too late packets, resend requests, min DAC queue size, min buffer occupancy, max buffer occupancy, source nominal frames per second, source actual frames per second, output frames per second, source clock drift in ppm, source clock drift sample count, rough calculated correction in ppm -``` -This will be followed by the statistics themselves at regular intervals, for example: -``` - 0.15, 0.0, 0.0, 1003, 0, 0, 0, 0, 8539, 208, 225, 44099.95, 44274.21, 44099.68, 0.00, 0, -6.12 - 0.34, 0.0, 0.0, 2006, 0, 0, 0, 0, 8591, 206, 225, 44099.99, 44169.96, 44099.76, 0.00, 0, -5.27 - 0.89, 0.0, 0.0, 3009, 0, 0, 0, 0, 8571, 218, 225, 44100.01, 44152.81, 44099.85, 0.00, 0, -3.66 - 0.85, 0.0, 0.0, 4012, 0, 0, 0, 0, 8619, 218, 225, 44100.00, 44142.80, 44099.80, 0.00, 0, -4.62 - 1.29, 0.0, 0.0, 5015, 0, 0, 0, 0, 8623, 218, 225, 44100.00, 44129.39, 44099.83, 0.00, 0, -3.85 - 1.41, 0.0, 0.0, 6018, 0, 0, 0, 0, 8619, 216, 225, 44099.99, 44127.74, 44099.86, 0.00, 0, -2.76 - 1.53, 0.0, 0.0, 7021, 0, 0, 0, 0, 8603, 218, 225, 44100.00, 44109.60, 44099.81, 0.00, 0, -4.21 - 1.81, 0.0, 0.0, 8024, 0, 0, 0, 0, 8655, 215, 225, 44100.00, 44110.01, 44099.82, 0.00, 0, -4.16 - 2.00, -82.1, 82.1, 9027, 0, 0, 0, 0, 8481, 208, 225, 44100.00, 44110.69, 44099.83, 0.00, 0, -3.97 - 1.96, -8.5, 8.5, 10030, 0, 0, 0, 0, 8599, 209, 225, 44099.99, 44108.84, 44099.86, 0.00, 0, -3.02 - 1.94, 0.0, 0.0, 11033, 0, 0, 0, 0, 8583, 217, 225, 44100.00, 44109.33, 44099.87, 0.00, 0, -2.93 - 1.90, -5.7, 5.7, 12036, 0, 0, 0, 0, 8601, 219, 225, 44100.00, 44110.01, 44099.85, 20.47, 10, -23.88 - 2.02, -36.8, 36.8, 13039, 0, 0, 0, 0, 8488, 216, 225, 44100.00, 44107.18, 44099.85, 20.39, 12, -23.83 - 1.96, -17.0, 17.0, 14042, 0, 0, 0, 0, 8554, 218, 226, 44100.00, 44108.80, 44099.84, 20.63, 15, -24.13 - 1.99, -31.2, 31.2, 15045, 0, 0, 0, 0, 8592, 216, 225, 44100.00, 44106.85, 44099.85, 20.95, 18, -24.39 - 1.98, -28.3, 28.3, 16048, 0, 0, 0, 0, 8627, 219, 225, 44099.99, 44109.01, 44099.88, 21.23, 20, -23.90 - 2.01, -31.2, 31.2, 17051, 0, 0, 0, 0, 8582, 217, 225, 44100.00, 44108.86, 44099.84, 21.57, 22, -25.10 - 1.96, -19.8, 19.8, 18054, 0, 0, 0, 0, 8556, 215, 226, 44100.00, 44103.79, 44099.86, 21.59, 24, -24.85 - 1.98, -25.5, 25.5, 19057, 0, 0, 0, 0, 8563, 219, 225, 44100.00, 44102.62, 44099.86, 22.26, 25, -25.47 - 2.00, -28.3, 28.3, 20060, 0, 0, 0, 0, 8569, 214, 225, 44100.00, 44103.22, 44099.88, 22.57, 27, -25.41 - 1.98, -42.5, 42.5, 21063, 0, 0, 0, 0, 8570, 216, 225, 44100.00, 44104.14, 44099.85, 22.74, 28, -26.08 - 1.89, -31.2, 31.2, 22066, 0, 0, 0, 0, 8524, 218, 225, 44100.00, 44104.66, 44099.87, 22.89, 30, -25.89 - 1.96, 0.0, 0.0, 23069, 0, 0, 0, 0, 8650, 218, 225, 44100.00, 44105.36, 44099.88, 22.92, 32, -25.73 - 1.98, -34.0, 34.0, 24072, 0, 0, 0, 0, 8475, 219, 225, 44100.00, 44106.04, 44099.88, 22.90, 34, -25.70 - 2.07, -138.8, 138.8, 25075, 0, 0, 0, 0, 8490, 218, 226, 44100.00, 44104.93, 44099.87, 23.87, 35, -26.92 - 1.33, 0.0, 0.0, 26078, 0, 0, 0, 0, 8617, 216, 225, 44100.00, 44104.66, 44099.88, 23.68, 38, -26.43 - 1.67, -22.7, 22.7, 27081, 0, 0, 0, 0, 8562, 217, 225, 44100.00, 44106.16, 44099.87, 25.06, 40, -27.93 - 1.98, -28.3, 28.3, 28084, 0, 0, 0, 0, 8544, 218, 225, 44100.00, 44105.21, 44099.87, 25.91, 41, -28.84 - 1.99, -22.7, 22.7, 29087, 0, 0, 0, 0, 8569, 219, 225, 44100.00, 44102.30, 44099.87, 25.91, 41, -28.74 - 1.66, -56.6, 56.6, 30090, 0, 0, 0, 0, 8554, 218, 225, 44100.00, 44103.07, 44099.86, 26.38, 44, -29.46 - 1.44, 0.0, 0.0, 31093, 0, 0, 0, 0, 8642, 218, 225, 44100.00, 44102.18, 44099.87, 26.08, 46, -28.98 - 1.56, 0.0, 0.0, 32096, 0, 0, 0, 0, 8647, 218, 225, 44100.00, 44102.76, 44099.87, 25.79, 48, -28.64 - 1.68, 0.0, 0.0, 33099, 0, 0, 0, 0, 8647, 217, 225, 44100.00, 44103.41, 44099.88, 25.66, 49, -28.51 - 1.92, -14.2, 14.2, 34102, 0, 0, 0, 0, 8639, 217, 225, 44100.00, 44102.38, 44099.87, 25.45, 51, -28.40 - 2.00, -45.3, 45.3, 35105, 0, 0, 0, 0, 8593, 216, 225, 44100.00, 44103.23, 44099.86, 25.35, 53, -28.61 - 1.98, -17.0, 17.0, 36108, 0, 0, 0, 0, 8609, 218, 225, 44100.00, 44102.54, 44099.87, 25.21, 55, -28.12 - 1.99, -31.2, 31.2, 37111, 0, 0, 0, 0, 8575, 217, 225, 44100.00, 44101.98, 44099.88, 25.11, 57, -27.88 - 1.99, -14.2, 14.2, 38114, 0, 0, 0, 0, 8624, 218, 225, 44100.00, 44104.44, 44099.87, 24.95, 60, -27.97 - 1.99, -28.3, 28.3, 39117, 0, 0, 0, 0, 8582, 209, 225, 44100.00, 44104.91, 44099.86, 24.88, 62, -27.98 - 1.86, -17.0, 17.0, 40120, 0, 0, 0, 0, 8504, 207, 225, 44100.00, 44104.52, 44099.88, 24.66, 63, -27.39 - 1.96, -56.6, 56.6, 41123, 0, 0, 0, 0, 8517, 212, 226, 44100.00, 44102.29, 44099.88, 24.54, 66, -27.34 - 1.90, -36.8, 36.8, 42126, 0, 0, 0, 0, 8363, 218, 240, 44100.00, 44116.79, 44099.87, 24.55, 68, -27.48 - 1.89, 0.0, 0.0, 43129, 0, 0, 0, 0, 8487, 227, 241, 44100.00, 44117.57, 44099.88, 24.56, 69, -27.32 - 1.99, -22.7, 22.7, 44132, 0, 0, 0, 0, 8576, 227, 240, 44100.00, 44118.53, 44099.87, 24.57, 70, -27.44 - 1.98, -39.7, 39.7, 45135, 0, 0, 0, 0, 8593, 228, 240, 44100.00, 44113.88, 44099.87, 24.60, 73, -27.43 - 2.00, -34.0, 34.0, 46138, 0, 0, 0, 0, 8577, 227, 240, 44100.00, 44117.10, 44099.88, 24.65, 75, -27.46 - 1.98, -22.7, 22.7, 47141, 0, 0, 0, 0, 8591, 204, 240, 44100.00, 44102.78, 44099.87, 24.67, 77, -27.59 - 1.98, -17.0, 17.0, 48144, 0, 0, 0, 0, 8587, 216, 225, 44100.00, 44102.38, 44099.88, 24.67, 79, -27.42 - 1.99, -28.3, 28.3, 49147, 0, 0, 0, 0, 8590, 214, 225, 44100.00, 44102.70, 44099.87, 24.66, 80, -27.57 - 1.85, -62.3, 62.3, 50150, 0, 0, 0, 0, 8518, 217, 226, 44100.00, 44103.16, 44099.87, 24.70, 83, -27.55 - 1.90, -28.3, 28.3, 51153, 0, 0, 0, 0, 8617, 216, 225, 44100.00, 44102.60, 44099.88, 24.66, 85, -27.42 - 1.89, -5.7, 5.7, 52156, 0, 0, 0, 0, 8615, 218, 225, 44100.00, 44103.37, 44099.88, 24.65, 86, -27.39 - 1.96, -19.8, 19.8, 53159, 0, 0, 0, 0, 8600, 219, 225, 44100.00, 44103.77, 44099.87, 24.62, 89, -27.53 - 1.99, -22.7, 22.7, 54162, 0, 0, 0, 0, 8567, 216, 225, 44100.00, 44103.12, 44099.87, 24.57, 92, -27.45 -``` - -"Sync error in milliseconds" is the average deviation from exact synchronisation. The first line of the example above indicates that the output is on average 0.15 milliseconds behind exact synchronisation. Sync is allowed to drift by the `general` `drift_tolerance_in_seconds` setting — (± 0.002 seconds) by default — before a correction will be made. - -"Net correction in ppm" is actually the net sum of corrections — the number of frame insertions less the number of frame deletions — given as a moving average in parts per million. After an initial settling period, it represents the drift — the divergence between the rate at which frames are generated at the source and the rate at which the output device consumes them. In this case, the drift is negligible, but it can routinely be up to 150 ppm, especially with older machines. - -"Corrections in ppm" is the number of frame insertions plus the number of frame deletions (i.e. the total number of corrections), given as a moving average in parts per million. The closer this is to the net corrections, the fewer "unnecessary" corrections are being made. Third party programs tend to have much larger levels of corrections. - -"Min DAC queue size" is the minimum size the queue of samples in the output device's hardware buffer was measured at. It is meant to stand at 0.2 seconds = 8,820 frames at 44,100 frames per second, and will go low if the processor is very busy. If it goes below about 2,000 then it's an indication that the processor can't really keep up. - -"Source nominal frames per second" is the rate at which audio is being sent to Shairport Sync according to information supplied by the source itself. - -"Source actual frames per second" is the rate at which frames of audio are actually received by Shairport Sync. This can vary a great deal due to network conditions, but over a long time (more than 30 minutes) it should settle down to an accurate value. It does not account for retransmitted packets. - -"Output frames per second" is the actual rate at which frames of audio are taken by the output device. On a system with a well-conditioned `ntp`-based clock (and without output underruns) this figure should be very accurate after playing material continuously for a period. - -"Source clock drift in ppm" is an estimate of the difference in timekeeping between the audio source and the Shairport Sync device. It is calculated from a linear regression of drift sample data. The number of samples the estimate is based on is given in the next column, "Source clock drift sample count". - -"Rough calculated correction in ppm" is a very crude estimate of the amount of interpolation that needs to applied, on average, to keep sync. It is not really to be relied on at this time. - -For reference, a drift of one second per day is approximately 11.57 ppm. Left uncorrected, even a drift this small between two audio outputs will be audible after a short time. The above sample is from an iPhone XS Max to Shairport Sync running on a WiFi-connected Raspberry Pi 3 using an [IQaudIO Pi-DigiAMP+](http://iqaudio.co.uk/hats/9-pi-digiamp.html). - -It's not unusual to have resend requests, late packets and even missing packets if some part of the connection to the Shairport Sync device is over WiFi. Late packets can sometimes be asked for and received multiple times. Sometimes late packets are sent and arrive too late, but have already been sent and received in time, so weren't needed anyway... - - -WiFi Issues ---------- -If you are using WiFi, you should ensure that WiFi power management is off. See [TROUBLESHOOTING](https://github.com/mikebrady/shairport-sync/blob/master/TROUBLESHOOTING.md) for more details. - -Troubleshooting ---------------- -Please refer to [TROUBLESHOOTING](https://github.com/mikebrady/shairport-sync/blob/master/TROUBLESHOOTING.md) for a few hints, contributed by users. - -MQTT ---------------- -Please refer to the [MQTT INFO](https://github.com/mikebrady/shairport-sync/blob/master/MQTT.md) page for additional info on building, configuring and using MQTT to interface shairport-sync with common home automation systems (contributed by users). - -Packaging status ----------------- - -[![Packaging status](https://repology.org/badge/vertical-allrepos/shairport-sync.svg)](https://repology.org/project/shairport-sync/versions) +Timestamps are referenced relative to the source computer's clock – the "source clock", but timing must be done relative to the clock of the computer running Shairport Sync – the "local clock". So, Shairport Sync synchronises the source clock and the local clock, usually to within a fraction of a millisecond. In AirPlay 2, this is done with the assistance of a companion application called [NQPTP](https://github.com/mikebrady/nqptp) using a [PTP](https://en.wikipedia.org/wiki/Precision_Time_Protocol)-based timing protocol. In classic AirPlay, a variant of [NTP](https://en.wikipedia.org/wiki/Network_Time_Protocol) synchronisation protocols is used. diff --git a/RELEASENOTES-DEVELOPMENT.md b/RELEASENOTES-DEVELOPMENT.md new file mode 100644 index 00000000..e0ac0d8f --- /dev/null +++ b/RELEASENOTES-DEVELOPMENT.md @@ -0,0 +1,2373 @@ +Version 4.1-dev-532-g8dfebea2 +==== +**Enhancements** +* Improve the response of Shairport Sync when a Mac is woken up from sleep and continues playing e.g. a YouTube video. Shairport Sync should resume play in most circumstances. (BTW, the HomePod mini does not resume in these circumstances.) + +**Bug Fix** +* Make the RTSP idle checker a bit more resilient -- wait for the full timeout even if interrupted by e.g. `SIGINT`. Also signal to NQPTP when to stop listening when a session goes idle or stops. + +Version 4.1-dev-526-gfd880056 +==== +***Pesky Changes You Can't Ignore*** + +* **Important**. Please update and re-enable NQPTP. The Shared Memory Interface protocol that Shairport Sync and NQPTP use to communicate with one another has been updated to reflect changes in NQPTP's operation. + +Apart from moving to the new SMI interface for NQPTP, this update consists of many small enhancements and bug fixes. (Yeah, and the build number really did go backwards...) + +Version 4.1-dev-535-gdafd1726 +==== +**Bug Fix** +* Fix yet another bug in the Makefile.am. Thanks to [Isioma Nnodum](https://github.com/mikebrady/shairport-sync/issues?q=is%3Apr+author%3Aicompuiz) for finding and [fixing](https://github.com/mikebrady/shairport-sync/pull/1536) it. + +Version 4.1-dev-520-g1092a8c1 +==== +**Enhancements** +* It is now possible to build Shairport Sync in a separate directory, thanks mainly to the work [#1493](https://github.com/mikebrady/shairport-sync/pull/1493) and [#1500](https://github.com/mikebrady/shairport-sync/pull/1500) of [Lukas Rusak](https://github.com/lrusak). A number of subsequent changes were necessary to make it work for FreeBSD. +* Shairport Sync should build on piCore. Thanks to [jackaroo](https://github.com/94jackaroo) for [reporting](https://github.com/mikebrady/shairport-sync/pull/1528) and checking. + +Version 4.1-dev-516-ga617e607 +==== +**Updates and Enhancements** +* The Docker image has been enhanced. Thanks, as always, to [Charles Omer](https://github.com/charlesomer). More changes are on the way here. + +**Bug Fixes** +* With Realtime Streams, if even one timing control packet was missing, Shairport Sync would work as if the sender had disappeared and cause a playback interruption. This has been modified so that it takes at least three missing control packets in a row to conclude that the sender was gone. Thanks to [Devid Leibovic](https://github.com/dasl-) for a [very thorough investigation](https://github.com/mikebrady/shairport-sync/issues/1515) of this issue. + +Version 4.1-dev-494-gd34db2a4 +==== +* The [CAR INSTALL.md](https://github.com/mikebrady/shairport-sync/blob/development/CAR%20INSTALL.md) guide has been updated for AirPlay 2 and for Raspberry Pi OS (Bullseye). +* A few noisy debug messages have been removed or quietened. Thanks to [David Leibovic](https://github.com/dasl-) for [the report](https://github.com/mikebrady/shairport-sync/issues/1513). + +Version 4.1-dev-468-gcb03d5c6 +==== +**Updates and Enhancements** +* The `development` branch now builds again on macOS with [brew](https://brew.sh). (Remember, though, that Shairport Sync [will not function in AirPlay 2 mode on a Mac](https://github.com/mikebrady/shairport-sync/blob/development/AIRPLAY2.md)). +* The `libao` backend has been updated to address an issue with the system becoming unavailable. The biggest change was to close the driver as soon as playing stops, reopening it when playing restarts. +* The `libao` drivers are now listed in the help text. If available, it is suggested that the `alsa` driver be used in preference to the `pulseaudio` driver. + +**Bug Fixes** +* The classic AirPlay build now works properly again with `tinysvcmdns` and `dns_sd`. + +Version 4.1-dev-466-g05dfcdfd +==== +**Enhancements** + +These are for advanced users. +* Add a new `Protocol` property to the D-Bus interface. Values: `AirPlay` if built for AirPlay and `AirPlay 2` if build for AirPlay 2. +* Add a new `Volume` property to the D-Bus interface. This enables you to get and set the volume _locally_. Use this carefully: it means that you can set the volume of the player without changing it at the source (e.g. iTunes / Music). The source will not be informed of the change, so the volume it sets and and the actual volume may become different. It is preferable to use remote control (if available) to "ask" the player to change the volume. +* Add a new `DropSession` method. This will immediately and forcibly terminate a playing session without informing the source. Use it carefully. It is preferable to use remote control (if available) to "ask" the player to stop playing. + +Version 4.1-dev-454-ga774a6fc +==== +**Enhancement** +* Strip the trailing dot and everything after it in the hostname when using it as the basis for a service name. E.g. `freebsd.local` becomes `freebsd`. + +**Bug Fixes** +* Fix a few compilation bugs and portability issues, and turn off deprecation warnings when compiling for Mac OS. + +**Note:** After this update, you'll need to run `autoreconf -fi` and the `./configure...` steps again. + +Version 4.1-dev-439-gb7a11cae +==== +Documentation update. Comments, corrections and suggestions welcome. + +Version 4.1-dev-429-g449e024c +==== +**Enhancement** +* With the ALSA backend, if the `default` device isn't available, Shairport Sync will now try to use `"hw:0"` instead. Background: the default ALSA device is sometimes a pseudo device provided by a sound server such as PipeWire or PulseAudio to play audio from ALSA-compatible programs. But it's not always available to all users, especially daemons like Shairport Sync. This simple change will try to use the first ALSA hardware device -- card 0 -- if the default output device is inaccessible with error code `EHOSTDOWN`. It allows Shairport Sync to work on default settings with Fedora 36. + +Version 4.1-dev-424-g4729e325 +==== +**Enhancements** +* Shairport Sync should no longer terminate if its ALSA output device is busy. This is useful when using ALSA devices in systems with sound servers such as PulseAudio or PipeWire. Shairport Sync now simply waits until the device becomes available. Shairport Sync retains exclusive access to the device (and so the sound server can not use it) until it is finished playing. + +* Wait up to ten seconds (was two seconds) for NQPTP to come online when starting up -- AirPlay 2 only. + +Version 4.1-dev-420-g23d0502f +==== +**Bug Fix** +* This commit reverses the enhancement in Version 4.1-dev-418-g5011dc09 because it doesn't work properly. Specifically, some service files are not being renamed and installed correctly. Apologies for the inconvenience. +**Note** After pulling this update, you should rerun the `$ autotools -fi` and `$ ./configure...` steps. + +Version 4.1-dev-418-g5011dc09 +==== +**Enhancement** +* The `Makefile.am` file has been updated to allow allow building and installing from a separate build directory. Thanks to [Lukas Rusak](https://github.com/lrusak) for the [contribution](https://github.com/mikebrady/shairport-sync/pull/1493). +**Note** After pulling this update, you should rerun the `$ autotools -fi` and `$ ./configure...` steps. + +Version 4.1-dev-412-gf218a4d4 +==== + +**Note** -- A bug has been fixed in NQPTP -- please update it. + +**Reversion** +* The change to the allowed settling time mentioned below has been reverted back to 5.0 seconds – the issue this was meant to address turned out to be a bug in NQPTP. + +Version 4.1-dev-409-g6bfeb49f +==== +**Bug Fix** +* Shorten the settling time (from 5.0 seconds to 0.75 seconds) allowed when a new AirPlay 2 player, with its own clock, is added or removed from the devices currently playing. The problem was that if something else happens during the settling time, the changeover to the new clock may fail. This doesn't eliminate the issue, but hopefully it stops it being a problem for the user. + +Version 4.1-dev-376-gca6e768f +==== +**Bug Fix** +* Fix a bug that permitted clipping to occur when the `playback_mode` as set to `mono`. Thanks to [xStatts](https://github.com/xStatts) for the [report](https://github.com/mikebrady/shairport-sync/issues/1491) and for checking the fix. + +Version 4.1-dev-357-gf551274a +==== +Explore remote control a bit more. No progress to report... + +Version 4.1-dev-352-g4d608216 +==== +**Bug Fix** +* Fix a bug in the activity monitor that could potentially allow the `run_this_before_entering_active_state` hook to be called more than once when the player was going active. It could also potentially allow the `run_this_after_exiting_active_state` hook to be called more than once when the player was leaving the idle state, but only if the `active_state_timeout` was set to 0. Thanks to [Ben Willmore](https://github.com/ben-willmore) for the [report](https://github.com/mikebrady/shairport-sync/issues/1440). + +**Enhancement** +* Allow procedures hooked to `run_this_before_entering_active_state` and `run_this_after_exiting_active_state` to run without the `activity_monitor_mutex` in the locked state. + +Version 4.1-dev-350-g82849e0d +==== +**Change** +* Return 501 instead of 404 for unimplemented GETs in AirPlay 2 mode. + +Version 4.1-dev-347-g6556a79d +==== +**Bug Fix** +* If a speaker with its own master clock (e.g. a HomePod mini) was added and then removed from the group of output speakers in AirPlay 2 mode, Shairport Sync would stop working. + +**Note** -- there is an important update to NQPTP out as well. + +Version 4.1-dev-340-g4705be9b +==== +**Enhancement** +* Improve the AAC decoder check by iterating through all formats the AAC decoder supports. + +Version 4.1-dev-332-g38c43f07 +==== +**Bug Fixes** +* Fixed a bug where the AAC decoder check would not recognise the AAC decoder in `ffmpeg` version 3. Thanks to [GXJ0102](https://github.com/GXJ0102) for help with this. +* Fixed a bug where, on a very fast CPU, `"basic"` interpolation would be chosen instead of `"soxr"` interpolation. + +**Enhancement** +* Relax the "fully-up-to-date" system requirement slighty -- Shairport Sync will build and run on Ubuntu 18.04 LTS. + +Version 4.1-dev-317-g0dc34a46 +==== +***Pesky Changes You Can't Ignore*** + +A change has been made the `shairport-sync`service/startup files, so before updating, please rerun the `./configure...` step and (Linux only) remove the existing service file as follows: +``` +$ ./configure ... # whatever your preferred options are... +# rm /lib/systemd/system/shairport-sync.service # Linux only -- no need for this in FreeBSD +``` +**Enhancements** +* The AAC decoder check for AirPlay 2 operation was temporarily removed but has now been reinstated and is working again. If it is causing problems, please let us know. A section has been added to the [TROUBLESHOOTING.md](https://github.com/mikebrady/shairport-sync/blob/development/TROUBLESHOOTING.md#aac-decoder-issues-airplay-2-only) document. +* Debugging and statistical information now outputs to `STDERR` by default, so the rather confusing `-u` command line option is no longer needed. This has the following implications: + * If Shairport Sync is run from a terminal window, then messages, warnings, debug and statistical information will appear on the terminal window. + * If Shairport Sync is run as a daemon, then `STDERR` will be redirected to the system log. + * If you wish to use [syslog](https://en.wikipedia.org/wiki/Syslog) (e.g. you might wish to see the different levels of highlighting of different categories of information), +there is a new command line option `--log-to-syslog`. (This is used by the modified startup scripts.) +* The `-u` option is now redundant and is deprecated (see above). +* A new command line option `--log-to-syslog` allows you to direct messages, warnings, debug and statistical information to [syslog](https://en.wikipedia.org/wiki/Syslog). For full effect, it should be the first argument in your list of command line arguments. It is really intended for when Shairport Sync is run as a daemon. + +Version 4.1-dev-283-ga62e4b0b +==== +**Enhancements** +* FreeBSD compatibility. Shairport Sync (and NQPTP) can now work in AirPlay 2 mode on a FreeBSD system. Note that the build instructions and the configuration parameters have changed -- `libdaemon` is no longer needed and should not be included. +* Certain Linux distributions -- notably Fedora 36 -- do not include a suitable AAC decoder for decoding AirPlay 2 Buffered Audio streams. Shairport Sync now includes a check to ensure that the AAC decoder can decode the stream, which seems to be encoded in Floating Point Linear Planar AAC ("`fltp`") format. (The AAC decoder is provided by the [`libavcodec`](https://www.ffmpeg.org/libavcodec.html) library, part of the [`ffmpeg`](https://www.ffmpeg.org) multimedia framework. For troubleshooting, the [`ffmpeg`](https://www.ffmpeg.org/ffmpeg.html) command line tool is very useful.) + +Version-4.1-dev-266-g1d228870 +==== +**Minor Changes** +* Cosmetic changes -- some debug and informational messages altered. + +Version-4.1-dev-255-g8a2756b7 +==== +**Bug Fix** +* Fix an audible interruption that could happen in certain circumstances when an output device was added or removed to a group of output devices. The "certain circumstances" are when the following two conditions are true: + 1. An AirPlay 2 Realtime Stream is playing, + 2. The new output device's clock takes or relinquishes control of output timing. + +For example, (i) when playing Spotify on an iOS device (this currently uses an AirPlay 2 Realtime Stream) to a Shairport Sync device and (ii) adding or removing a HomePod mini as an output device (the HomePod mini's clock will take or relinquish control of output timing). + +**Enhancement** +* When a Shairport Sync device is added as an output device to a stream that is already playing, it now mutes for two seconds to improve synchronisation when it joins in and actually starts producing audio. The previous slight lack of synchronisation was inaudible, but would require some interpolation before settling down. + +Version-4.1-dev-249-g38bbad6f +==== +**Bug Fix** + +* Fix a bug in the `systemd` startup file. The bug was that even when Shairport Sync was built without Avahi support, Shairport Sync would not launch until the Avahi service was available. Thanks to [klslz](https://github.com/klslz) for reporting the problem in issue [#1454](https://github.com/mikebrady/shairport-sync/issues/1454). + + +Version-4.1-dev-247-ga295c2a2 +==== +**Bug Fix** + +* Fix a bug in the logic for suppressing clicks when the `alsa` `disable_standby_mode` is active. + +Version-4.1-dev-245-gf34a69fa +==== +**Enhancement** + +* AirPlay 2 only. Two new metadata messages have been added. They might be useful for amplifier switching, etc. +1. The `conn` message signifies "AirPlay 2 connect" and is sent when an AirPlay 2 device selects this player. It is sent _before_ killing any current play session. + + (Note: in AirPlay 2 operation, the existing `clip` message is identical, but it is sent _after_ any existing play session has been terminated.) + +2. The `disc` message signifies "AirPlay 2 disconnect". + + +Version-4.1-dev-242-g3877acc7 +==== +**Bug Fix** +* Fix a crash that would occur after days of continuous play. The issue was that each time a cover art file was created (and previous cover art deleted) the coverart directory was opened with `open()`, but was not closed with `close()`. + +Version-4.1-dev-238-g1dc481c3 +==== +**Enhancement** +* Add some extra diagnostic information when large sync errors occur: if available, add the total number of frames sent to the output device and also, if available, add the current delay, in frames, in the output device. + +Version-4.1-dev-234-ge8721889 +==== +**Bug Fix** +* Fixed a bug using HomePod Software 15.4. The bug was that when a Shairport Sync device was added as a HomePod output device, visually it didn't appear to join the group of output devices and additionally its volume control could not be accessed. The bug was fixed by increasing the maximum permissible length of ID strings in Shairport Sync. + +Version-4.1-dev-229-g08afa822 +==== +**Enhancement** +* Add _Minimum Buffer Size_ to statistcs information for a Buffered Audio stream (and remove the minimum and maximum number of decoded buffers -- they are not too interesting). The Minimum Buffer Size gives the smallest size, in bytes of kilibytes, of the buffer of audio that has yet to be decoded during the last statistics interval. The larger it is, the longer Shairport Sync can play while a network outage is occuring. It can legitimately be zero at the start of a track, and obviously it can reach zero at the end of a track, but if it is zero while a track is playing, it may indicate problems with the network. + +Version-4.1-dev-224-g29d2155e +==== +***Pesky Change You Can't Ignore*** + +A change has been made the `shairport-sync` `systemd` service file, so before updating, please remove the existing service file with the following command: +``` +# rm /lib/systemd/system/shairport-sync.service +``` +**Bug Fixes** +* Interpret `disable_standby_mode` to determine if a flush should also close an `alsa` device as follows: + 1. If `disable_standby_mode` is set to `"no"` (default) or `"never"`, then a flush will immediately close the `alsa` device. + 2. If `disable_standby_mode` is `"auto"`, a flush will not close the `alsa` device. The device will be closed at the end of the active timeout. + 3. If `disable_standby_mode` is `"yes"` or `"always"`, a flush will not close the `alsa` device. The device will never be closed. + +* Remove the invalid `Provides` entry from the `systemd` service file. Thanks to [David Crook](https://github.com/idcrook) for reporting Issue [#1448](https://github.com/mikebrady/shairport-sync/issues/1448). + +Version-4.1-dev-214-gadf0845e +==== +**Enhancement** +* Check to see if the alsa_handle is NULL in `precision_delay_and_status`. + +Version-4.1-dev-211-g9bac04e2 +==== +**Bug Fix** +* Check for `NULL` pointers before dereferencing delay and state variable pointers in `audio_alsa.c`'s `delay` and `*-delay_and_status` functions. Thanks to [leirace](https://github.com/leirace) for the report, Issue [#1441](https://github.com/mikebrady/shairport-sync/issues/1441). + +Version-4.1-dev-209-gb4cd4fbc +==== +***Pesky Change You Can't Ignore*** + +A change has been made the `shairport-sync` `systemd` service file, so before updating, please remove the existing service file with the following command: +``` +# rm /lib/systemd/system/shairport-sync.service +``` +**Enhancements** +* Improve the timing service interface: Instead of opening and closing a Shared Memory Interface (SMI) whenever timing information was needed from NQPTP, the SMI is now opened only once, at startup. Overall, this reduces overhead at critical times and seems to improve the initial accuracy of synchronisation. It also requires the NQPTP service to be available and accessible at startup. +* Improve `alsa` flush performance: Add new code to better handle a flush request in the `alsa` backend. This new code results in smoother operation and timing accuracy is improved when continuing after a flush. +* Define the Shairport Sync service in the `systemd` service file. + +**Bug Fix** +* Fix a bug that caused a crash if an incorrect `wait_for_completion` option was chosen. Fixed a few similar bugs too. Thanks to [HiFiBerry](https://github.com/hifiberry) for reporting the issue at [#1431](https://github.com/mikebrady/shairport-sync/issues/1431). + +Version-4.1-dev-193-g4848608d +==== +* Don't try to decode commands at debug level 2 -- leave it to level 3. + +Version-4.1-dev-191-ge07c202b +==== +#### Enhancement +* This enhancement relates to MQTT with empty payloads. Many MQTT brokers and clients treat messages with empty payloads in a special way. For instance, [MQTT Explorer](http://mqtt-explorer.com) hides messages with empty payloads and [Node-RED](https://nodered.org) seems to use them to release and garbage-collect data received previously. +Many Shairport Sync messages contain no extra data and so would naturally have empty payloads. This is causing problems -- see [#1425](https://github.com/mikebrady/shairport-sync/issues/1425) and [#1375](https://github.com/mikebrady/shairport-sync/issues/1375). To avoid these problems, a short "dummy" payload consisting of the character string "--" is now added to MQTT messages that contain no extra data. This can be changed with a new MQTT option in the configuration file: `empty_payload_substitute`. Thanks to [DOCaCola](https://github.com/DOCaCola) and [UMB8998](https://github.com/UMB8998) for reporting on this. + +Version-4.1-dev-188-gf135d857 +==== +#### Bugfixes +* Ensure that when `ignore_volume_control` is true, the volume metadata has the current, max and min values of the [now ignored] attenuator set to 0.0. Thanks to [Michael Daley](https://github.com/greend139) for reporting in Issue [#1417](https://github.com/mikebrady/shairport-sync/issues/1417). +* Add a fix for v3 of s6 overlay and other improvements to the Docker image. Thanks to [Charles Omer](https://github.com/charlesomer) for the fix and the improvements and thanks to [rdrdog](https://github.com/rdrdog) for reporting the issue. + +#### Other Changes +* Add code to check certain 32-bit and 64-bit conversions. + +Version-4.1-dev-173-gdeb11654 +==== +#### Enhancements +* Add some sanity checking of the latency offset and buffer size to check if they can be accommodated. +* Discard non-sentinel UDP timing packets that are received just when a timing thread starts -- they may relate to a prior session. + +Version-4.1-dev-171-g703717a5 +==== +#### Bugfix +* Clear PTP clock information when a Realtime stream stops playing. This _may_ address one of the issues reported in [#1404](https://github.com/mikebrady/shairport-sync/issues/1404). + +Version-4.1-dev-169-g6ced6bc6 +==== +#### Enhancement +* Add a new `mixer_control_index` setting to the `alsa` section of the configuration file. A mixer is fully identified by a name and index. The index defaults to zero, and, until now, it could only be set using the `alsa` command-line argument `-i`. Thanks to [flipoidix](https://github.com/flipoidix) for bringing this issue to notice. + +Version-4.1-dev-164-gf79222f7 +==== +#### Bugfix +* Fix a crashing bug in AirPlay 2 mode which occurs if no configuration file is found. This particularly affects the Docker image, as it contains no configuration file. Thanks to [Charles Omer](https://github.com/charlesomer) for reporting. + +Version-4.1-dev-160-g9c2f9f7a +==== +#### Bugfix +* Fix a crashing bug in AirPlay 1 ("Classic") mode, whereby if a session was abruptly interrupted, e.g. by the sudden loss of a network, Shairport Sync would crash. The problem was that the interrupted session was not correctly terminated. Thanks to [th0u](https://github.com/th0u) for reporting issue [#1398](https://github.com/mikebrady/shairport-sync/issues/1398). + +Version-4.1-dev-158-gb5860fc4 +==== +#### Enhancements +The following enhancements are mainly experimental, for advanced users only, and are intended to enable multiple instances of Shairport Sync (SPS) to run in one computer and provide multiple AirPlay 2 endpoints. At this point, multiple instances of SPS can indeed run on one machine and provide multiple AirPlay 2 endpoints, but unfortunately the presence of multiple services at the same address seems to confuse AirPlay 2 clients. So, it seems that while multiple instances of SPS can now run successfully on one device, they can't be used on the same network. +* Use a uniquely-named named SMI interface to get dedicated access to NQPTP. +* Simplify validation of the mDNS interface setting, if given. +* Exit with a warning if the player is using a name that already exists. +* Stop storing the timing peer list. +* Generate an initial timing list during setup — don’t wait for the first timing peer list message. May gain around 50 ms. +* Fix a bug and clean up generation of device's timing addresses. +* Add some control to the generation of the Device ID: +1. Revise how the Device ID is generated from the device’s MAC addresses +2. Add a setting to add a fixed offset to the automatically-generated Device ID. +3. Add a setting to specify a complete Device ID, replacing the automatically-generated Device ID. +* Be more careful to create default file names based on the name of the app. + +Version-4.1-dev-146-g42e508b4 +==== +#### Enhancements +* Extract several very useful extra pieces of client metadata for AP2. Many thanks to [Cody Cutrer](https://github.com/ccutrer). +* Enable a cleaner restart of the D-Bus daemon in a Docker image. Thanks again to [Charles Omer](https://github.com/charlesomer). + +Version-4.1-dev-138-g5617f40e +==== +#### Minor Internal Changes +* A small number of internal chages made. + +Version-4.1-dev-127-g4d0460b9 +==== +#### Enhancement +* Update the Docker workflow to automatically do Docker tagging and to use an s6-overlay implementation. Thanks to [Charles Omer](https://github.com/charlesomer) for all this work, and to [Robert Casties](https://github.com/robcast) for his s6-overlay Pull Request [#1349](https://github.com/mikebrady/shairport-sync/pull/1349) which formed the basis of the s6-overlay work. +* Slight documentation update, thanks to [michaeldeborst](https://github.com/michaeldeborst). + + +Version-4.1-dev-115-g8656149d +==== +* Simplify and improve timing when a play session from a new device is started. + +Version-4.1-dev-106-ge98111fb +==== +#### Enhancement +* Try to improve the reliability of restarting a "silent clock" device. + +Version-4.1-dev-104-g84dd2dc4 +==== +* Begin to explore some more connection types. + +Version-4.1-dev-102-g9bf45574 +==== +#### Enhancement +* Make debug messages in the system log easier to see on macOS Terminal (!) by outputting them at LOG_INFO level rather than LOG_DEBUG level. + +Version-4.1-dev-100-g8330f30b +==== +#### Enhancement +* Updated information on the statistics provided -- see [MOREINFO.md](https://github.com/mikebrady/shairport-sync/blob/development/MOREINFO.md#statistics). + +Version 4.1-dev-95-ga7a02083 +==== +#### Bug Fix +* Fixed a compilation bug that occurs if metadata support is not included in the build configuration. The fix was to add the appropriate conditional code statements. Thanks to [Daniel Gooß](https://github.com/Dangoo) and [winstonsetiawan](https://github.com/winstonsetiawan) for reporting. + +Version 4.1-dev-92-g3ab16b5d +==== +#### Enhancement +* Thanks to [Anton Lindqvist](https://github.com/mptre) for updates and bug fixes to building for OpenBSD. + +#### Other Updates +* Thanks to [tekdude](https://github.com/tecdude) for a documentation update. +* Various documentation updates. + +Version 4.1-dev-81-g24a5bbbe +==== +This is a pretty big under-the-hood update. + +#### Significant Changes +* Change clock base to improve stability. You need to use the updated `nqptp` that has also been changed. If you forget, Shairport Sync will not work properly and will leave a message in the log. +* Avoid skipping the first 100 milliseconds or so of a newly-selected track. +* Clean up the output of statistics — shorter when log verbosity is zero. +* Change behaviour after an unrecoverable error -- if not handled, exit Shairport Sync. +* Add client and server ip metadata for AP2 Buffered Audio Stream. + +#### Changes +* Add client and server ip metadata for AP2. Remove timing peer list and DACP code only for a full AP2 teardown. +* Fix a few memory leaks. Add bogus exits to allow SPS to quit at the end of a play session, to make it easier to use `valgrind`. +* Stop checking that the timing peers are within the same subnet. +* Look for at least 0.1 seconds of leadtime, ensure a master clock is at least 0.275 seconds old before use, quieten a few debug messages. +* Add txtAirPlay data to the get info response. +* Don't pause reception of long RTSP messages. +* Don't ask for cover art if not asking for metadata too, duh. +* Skip some types of invalid AAC packets. +* Don't decode outdated frames. +* Wait for timing information to be valid in AP2 Buffered Audio Streams processing. +* Set the timing peer list as soon as a SETPEERS message is received -- don't wait until play is about to begin. Not sure if it works universally yet. +* Tidy up the statistics printout table and stop outputting (non existent) nominal fps for AP2 Realtime Streams. +* Use PKG_CHECK_MODULES to find libavcodec, to make it work with Fedora 35 (?) +* Change behaviour after an unrecoverable error -- if not handled, exit Shairport Sync. +* log statistics headers whenever verbosity goes on or off or whenever statistics are requested +* Clean up statistics. +* Stop watchdog timing out AP2 sessions. +* Remove the commas in the statistics logs -- easier to get into a spreadsheet. +* Don't overwrite service files if they already exist. +* Try finding libplist as libplist-2.0 on Linux too. +* Move to using CLOCK_MONOLITHIC_RAW to avoid NTP effects. Bump interface version. +* Add code to check divisions and mods for a potential divide by zero problem. This may cause SPS to terminate but it will leave a log message. +* Add a 'stats' function to the audio back ends to replace the 'rate_info' function. Zero all except the alsa back end. +* Attempt to increase the precision of the FPS timing +* Update to the latest version of ejurgensen's pair_ap library. With thanks. + +#### Bug Fix +- This fixes [#1345](https://github.com/mikebrady/shairport-sync/issues/1345) by checking for the `libplist` library both under the name `libplist` and `libplist-2.0` using the fallback strategy [as described in the autotools docs](https://autotools.io/pkgconfig/pkg_check_modules.html). Since we now try both names, we no longer need the FreeBSD/Linux check. Many thanks to [FW](https://github.com/fwcd) for the bug report, the fix and this documentation! + +Version 4.1-dev-21-g1032cad6 +=== +#### Enhancement +- Update the `pair_ap` library to the [latest version](https://github.com/ejurgensen/pair_ap). Thanks again to [ejurgensen](https://github.com/ejurgensen). Addresses Issue [#1334](https://github.com/mikebrady/shairport-sync/issues/1334). Thanks to [iChUdY](https://github.com/iChUdY) for reporting the issue. + +Version 4.1-dev-19-g3f6f0932 +=== +#### Bug fix +- Fix a bug that would occasionally mute Shairport Sync when using it with AppleTV. Combined with the [recent update](https://github.com/mikebrady/nqptp/blob/development/RELEASE_NOTES.md) of `nqptp`, this makes using Shairport Sync much more useful with an AppleTV 4K. + +Version 4.1-dev-15-gf4115c45 +==== +#### Bug Fix +- Fix the following [buildroot](https://buildroot.org) build failure when the `--with convolution` flag is included. The issue is due to a change in the behaviour of automake 1.16.5 -- see [`https://git.savannah.gnu.org/cgit/automake.git/commit/?id=f4a3a70f69e1dbccb6578f39ef47835098a04624`](https://git.savannah.gnu.org/cgit/automake.git/commit/?id=f4a3a70f69e1dbccb6578f39ef47835098a04624): +``` +configure.ac:305: error: AM_INIT_AUTOMAKE expanded multiple times +/home/giuliobenetti/autobuild/run/instance-1/output-1/host/share/aclocal-1.16/init.m4:29: AM_INIT_AUTOMAKE is expanded from... +configure.ac:6: the top level +/home/giuliobenetti/autobuild/run/instance-1/output-1/host/share/aclocal-1.16/init.m4:29: AM_INIT_AUTOMAKE is expanded from... +configure.ac:305: the top level +``` +Fixes: +[`http://autobuild.buildroot.org/results/464148bdccb705d8992dc860262bfdeb01b7e2a1`](http://autobuild.buildroot.org/results/464148bdccb705d8992dc860262bfdeb01b7e2a1). + +Thanks to [Fabrice Fontaine](https://github.com/ffontaine) for [Pull Request #1314](https://github.com/mikebrady/shairport-sync/pull/1314). + + +Version 4.1-dev-9-gd2e35fc0 +==== +#### Bug Fix +- Fix an incompatibility with iOS 15.1 betas and release candidates. The problem was this: if an unknown RTSP command was received, Shairport Sync would return a HTTP error response code of 400 ("Bad Request") but the player would not continue. After some experimentation, it was discovered that a HTTP error response code of 501 ("Not Implemented") would allow the player to continue. Thanks to [corrpel](https://github.com/corrpel) and [bloomkd46](https://github.com/bloomkd46) for reporting the issue. + +Version 4.1-dev-4-g0fe21f3a +==== +#### Bug Fixes +- Fix a bug whereby the `volume_range_db` setting would be ignored if it was less than the range of the hardware mixer. +- Fix a bug that prevented an AirPlay 2 build if metadata was not enabled, either directly or indirectly, at the `./configure...` step. + +Version 4.1-dev +==== +#### Enhancement +- **Better Siri, HomePod mini and Home Integration** An AirPlay 2 build of Shairport Sync now provides a visible volume control when used by a HomePod mini. This should work for other devices too -- reports welcome. You can use the Home app and Siri to set and adjust the volume when used to play from the HomePod mini. + +Version 4.0-dev-308-g23da206 +==== +#### Bug Fixes +- Restore logging to `syslog`. + +Version 4.0-dev-303-g9074069 +==== +#### New Features +- An initial [PipeWire](https://pipewire.org) backend, with thanks to [Lukas Rusak](https://github.com/lrusak). Use the `--with-pw` configuration flag at the `./configure...` stage to include support. + +#### Bug Fixes +- Fix a bug when using the `tinysvcmdns` mDNS implementation, with thanks to [fesc2000](https://github.com/fesc2000). +- When an unrecognised SETUP message is received, just ignore it and put a warning in the log. Remove a redundant `client_setup_plist` data item from the `conn` data structure. + +#### Enhancements +- Shairport Sync no longer needs to be in the same directory as NQPTP during compilation. +- Add Docker automations -- thanks to [Charles Omer](https://github.com/charlesomer). +- Add Issue management automations -- thanks to [Charles Omer](https://github.com/charlesomer). +- Reconnect the DACP scanner for AirPlay 2. (It still isn't useful, unfortunately.) +- Add initial support to allow dynamic modification of Rendezvous advertisements. +- Simplify some UFW suggestions in the Troubleshooting Guide. +- Merge some documentation changes from the `master` branch. +- Add information to the Car Install Guide about improving boot times, thanks to [vasilisvg](https://github.com/vasilisvg) + +Version 4.0-dev-185-g0c02ee2 +==== + +#### New Features +- **Home App Integration** An AirPlay 2 build of Shairport Sync now offers limited integration with the Home app. Specifically, a Shairport Sync AirPlay 2 instance can now be added as a speaker to the Home app. Thanks to [ckdo](https://github.com/ckdo) and [ejurgensen](https://github.com/ejurgensen) for figuring this out and for coding it up. It means that some Siri interaction is possible. +- **Automated Docker Builds** Thanks to the work of [Charles Omer](https://github.com/charlesomer), Docker builds on the `development` branch should appear from time to time on the [Docker Hub](https://hub.docker.com/r/mikebrady/shairport-sync). + +#### Bug Fixes +- [Crashing bug fix](https://github.com/mikebrady/nqptp/blob/main/RELEASE_NOTES.md) in `nqptp` -- thanks to [ste94pz](https://github.com/ste94pz). +- Honour the `max_volume_db` setting even when `ignore_volume_control` is true. Note that dithering is enabled if software attenuation is needed. + +#### Other Changes +- Spell out `Shairport Sync` instead of `SPS` in a few places. +- Clang format some source files. + +Version 4.0-dev-153-g9ccde50 +==== + +Big Update +---- +Version 4 brings [limited AirPlay 2 functionality](https://github.com/mikebrady/shairport-sync/blob/development/AIRPLAY2.md) to Shairport Sync. + +For information about AirPlay 2, including acknowledgements, please visit [AIRPLAY2.md](https://github.com/mikebrady/shairport-sync/blob/development/AIRPLAY2.md). + +#### Known Issues +- In the AirPlay 2 build, a crash can occur occasionally when the player is being selected. If you can get this to happen reliably, please let us know. + +#### Warning + +1. Big changes have been made to the codebase to enable it to be used to build either as the "classic" AirPlay 1 player or as a new AirPlay 2 player. These changes have probably introduced bugs into the classic AirPlay 1 build. +2. There is lots we don't know about AirPlay 2. This can result in incorrect behaviour. Watch out for very high volume levels, especially if you have a powerful audio system. +3. This is a `development` branch and is probably more buggy than usual. Normal support will not be provided -- instead, we will be interested in bug reports that help improve the program. You need to be adept with Linux or FreeBSD to get involved. + +Version 3.3.8d7 +==== +**Bug Fix** +* Fix a bug in the `alsa` back end. In the interval between checking to see if the alsa device handle was NULL and actually using it, the handle could be set to NULL. The interval between check and usage is now protected. + +Version 3.3.8d6 +==== +**Bug Fix** +* Fix a bug in the `alsa` precision timing code. Thanks to [durwin99](https://github.com/durwin99), [Nicolas Da Mutten](https://github.com/cleverer), [mistakenideas](https://github.com/mistakenideas), [Ben Willmore](https://github.com/ben-willmore) and [giggywithit](https://github.com/giggywithit) for the [report](https://github.com/mikebrady/shairport-sync/issues/1158). + +Version 3.3.8d5 +==== +**Bug Fixes** +* Fix a fault in the configuration script `configure.ac` that caused the `libdaemon` library to be omitted even when requested. Thanks to [aleszczynskig](https://github.com/aleszczynskig) and [xska2](https://github.com/xska2) for the [report](https://github.com/mikebrady/shairport-sync/issues/1137). + +Version 3.3.8d4 +==== +**Bug Fixes** +* Fix a fault in the configuration script `configure.ac`. The fault was that a `--without-*` configuration argument was being misunderstood and interpreted partly as a `--with-*` argument. Thanks to [David Racine](https://github.com/bassdr) for the [report](https://github.com/mikebrady/shairport-sync/issues/1123). + +Version 3.3.8d3 +==== +**Enhancements** +* Documentation for the MQTT interface. Many thanks to [minix1234](https://github.com/minix1234)! + +**Bug Fixes** +* Fix a bug that caused Shairport Sync to hang, but not actually crash, if an on-play or any on-*** script failed. +* Fix a crash that occurred if metadata support is enabled during compilation but turned off in the configuration file. Thanks to [Tim Curtis](https://github.com/moodeaudio) for the report. +* Fix a crash that occurred playing from AirPower on Android. Thanks to [Ircama](https://github.com/Ircama) for the report. + +Version 3.3.8d2 -- 3.3.8d0 +==== +There are absent from the repository -- see `3.3.8rc0` and `rc1` in the `master` branch. + +Version 3.3.7d19 +==== +**Bug Fix** +* Ensure the metadata pipe is created, if necessary, when the `--with-metadata` configuration option is chosen without the `--with-dbus-interface`, `--with-mpris-interface` or the `--with-mqtt-client` options. Super thanks to [Philip Howard](https://github.com/Gadgetoid) for finding this and for developing a possible solution. + +**Enhancements** +* Add a default name for the `pipe` backend. If you don't specify a name for the `pipe` backend's named pipe, it will be `/tmp/shairport-sync-audio`. Note that Shairport Sync will need to have write permission to `/tmp` to create the pipe. + +Version 3.3.7d18 +==== +**Bug Fix** +* Make the first output backend in the list of backends the default, and make its name the default output_name. Clang-format everything. Thanks again to [kiwi-ed](https://github.com/kiwi-ed) for bringing this issue to light. + +Version 3.3.7d17 +==== +**Bug Fix** +* Include the word `jack` in the version string if support for [Jack Audio](https://jackaudio.org) is included. Thanks to [kiwi-ed](https://github.com/kiwi-ed) for bringing this issue to light. + +Version 3.3.7d16 +==== +**Bug Fix** +* Fix potential inability to restore synchronisation quickly in certain situations. + +Version 3.3.7d15 +==== +**Enhancements** +* Changed permissions when creating the metadata pipe (and the audio pipe in the `pipe` backend) to `rw-rw-rw-` for compatibility with `snapserver`. + +Version 3.3.7d14 +==== +**Enhancements** +* Fixed a situation where a misleading error message was given if a configuration file cound not be located and `get_coverart` was selected as a command line option. Apart from a misleading message, `get_coverart` and `enable_metadata` should have been enabled automatically where metadata support is included in the build configuration. Thanks to [Craig Fletcher](https://github.com/leakypixel) for the bug report. + +Version 3.3.7d13 +==== +This is 3.3.7rc1 + +**Enhancements** +* Fixed another bug, related to the bug fixed in 3.3.7d4, where leading zeros were not removed from the DACP ID. Thanks again to [julianc1969](https://github.com/juliandc1969). + +Version 3.3.7d12 +==== +This is 3.3.7rc0 + +**Enhancements** +* Added the the string `-alac` to the the version string in '-V' if Apple ALAC decoder support is included. + +Version 3.3.7d11 +==== +**Bug Fixes** +* Fixed a number of bugs that prevented Shairport Sync from terminating cleanly in response to the `MPRIS` interface's `Quit()` command. Thanks to [João Gabriel](https://github.com/jgabriel98) for reporting this issue. +* Related to the above, the code used to terminate the application after a fatal error has been cleaned up. It now uses the correct `exit()` call rather than the rather hacky `abort()` call, returning the value of the constant `EXIT_FAILURE` (typically `1`) to the caller . + +Version 3.3.7d10 +==== +**Bug Fix** +* Fixed a bug whereby the start and end of active mode tokens `abeg` and `aend` where not generated or published -- `pend` tokens were being generated instead. Thanks to [minix1234](https://github.com/minix1234) for the bug report and [fix](https://github.com/mikebrady/shairport-sync/pull/1023). + +**Enhancements** +* Cleaned up and simplified the code that handles `FLUSH` requests coming from the player. (Debug messages are still a little verbose.) + +Version 3.3.7d9 +==== +**Enhancements** +* Improved timing estimation. Shairport Sync has been using linear least-squares regression to estimate timing drift between the (remote) source clock and the local clock. This technique is now extended to provide an estimate of the remote-to-local clock difference itself. (The remote-to-local clock difference is used to remap the timing of audio frames from the remote device's clock to the local clock.) + + Timing drift estimates are now saved when a sessions ends, keyed to the client IP number. When a new session starts from that IP number, the stored estimate is used until a new estimate can be generated from the new session. + + In practice, the timing techniques in use up to now have been very accurate, but this should result in slightly smoother rates of correction. + +Version 3.3.7d8 +==== +**Enhancements** +* Tidied up the creation and initial opening of pipes. Suppress repeated pipe-opening error messages. +* Tidied up warnings and fatal error messages when log verbosity is zero. +* Cleaned up the code that provides a silent lead-in to play on a back end without synchronisation, e.g. a pipe or `stdout`. +* Added in commented-out code to check the timeliness of the release of audio to a back end without synchronisation, e.g. a pipe or `stdout`. TL;DR – so long as the back end does not block, frames will be released to it not more than one packet (352 frames) late. + +Version 3.3.7d7 +==== +**Enhancements** +* Logs and statistics can now be directed to the system log (default), `stdout`, `stderr` or to a file or pipe of your choice using a new setting, `log_output_to` in the `diagnostics` section of the configuration file. This is very useful when the system log is disabled or diverted. +* Audio data from the `pipe` back end and metadata from the metadata pipe are now written using standard blocking `write` commands rather than a slightly complex non-blocking write function. Pipes are now opened in non-blocking mode and changed to blocking mode when successfully opened. +* Separate threads are now used for each metadata subsystem. Until now, all metadata was processed on a single thread. This included writing to the metadata pipe and the multicast stream and supplying metadata for the `mqtt` interface and for the `dbus` and `MPRIS` interfaces. Unfortunately, that meant that a problem with any one of these subsystems could propagate into the others. Now they all run on separate threads. If one thread blocks, it will not interfere with the other subsystems. + +Version 3.3.7d6 +==== +**Bug Fixes and Enhancements** +* Fixed a bug calculating the instantaneous synchronisation error. This bug could occasionally cause Shairport Sync to lose synchronisation and maybe even to mute for a few seconds before resynchronising. It was caused doing modulo arithmetic incorrectly and it's been there for a while. +* Cleaned up and improved the code to synchronise the first frame of audio. This should result in more accurate and reliable initial synchronisation, usually to under a millisecond, and often to within 20 or 30 microseconds. Syncronisation should improve even when the silent lead-in time is as short as 0.3 seconds or when the `audio_backend_latency_offset_in_seconds` is as much as -1.7 seconds, i.e. when only 0.3 seconds of latency are left when the latency would normally be 2.0 seconds. +* Removed a bug which would affect initial synchronisation if a `FLUSH` command was received from the player at an inopportune time. +* Cleaned up some confused uses of modulo arithmetic. +* Cleaned up the allocation of memory for gathering running statistics – the heap is now used instead of the stack. +* Cleaned up the display of statistics for backends that do not implement active synchronisation, e.g. the `pipe` and `STDOUT` back ends. + +Version 3.3.7d5 +==== +**Bug Fixes and Enhancements** +* Added code to do calculations involving the `audio_backend_latency_offset_in_seconds` and `audio_backend_silent_lead_in_time` settings correctly. Many thanks to [Tucker Kern](https://github.com/mill1000) for discovering a number of bugs associated with this and for [proposing a solution](https://github.com/mikebrady/shairport-sync/pull/1001). This prompted a closer investigation and a number of further improvements were made, and a few "hostages to fortune" removed. +* Cleaned up the `audio_backend_silent_lead_in_time` setting by adding an `"auto"` setting. +* Improved synchronisation accuracy with short silence lead-ins. + +**New Feature** +* For the PulseAudio backend `pa`, added a new `server` entry to the `pa` section of the configuration file, allowing you to specify a connection to a remote or a local system PulseAudio instance instead of letting PulseAudio choose. Thanks to [Guillaume Revaillot](https://github.com/grevaillot) for this new feature. + +Version 3.3.7d4 +==== +**Bug Fix** +* The DACP ID looks like a 64-bit number expressed in hexadecimal. It is normally quoted with leading zeroes removed, but in the `_dacp._tcp` service string, leading zeros are not removed from the DACP ID. The bug fix removes those leading zeroes. Thanks to [julianc1969](https://github.com/juliandc1969) for tracking down this bug so tenaciously! + +Version 3.3.7d3 +==== +**Enhancement** +* While a player is active, the DACP port number to which to send remote commands should be broadcast over ZEROCONF/Bonjour. However, if that information is not available, Shairport Sync will now check for it every two seconds. + +Version 3.3.7d2 +==== +**Pesky Changes** +* The underlying timing system has been moved from 64-bit fixed-point time representation (like NTP) to a 64-bit unsigned nanoseconds representation. This should make precisely no difference to the functionality of Shairport Sync but the transition might inadvertently have introduced bugs. Problem reports gratefully received. + +**Enhancement** +* The timing software in the `sndio` backend does some extra sanity checking on certain time estimates, it may help a little when running on virtual machines. + +Version 3.3.7d1 +==== +This is 3.3.6 with some documentation updates. + +Version 3.3.6d11 = Version 3.3.6 +==== +**Bug Fix** +* Avoid using `strndup` as it seems older versions of OpenWrt do not recognise it. + +Version 3.3.6d10 +==== +**Bug Fix** +* Brown-bag fix -- do what 3.3.6d9 was supposed to do! + +Version 3.3.6d9 +==== +**Bug Fix** +* Fix a bug in the provision of metadata which would on occasion cause metadata from the previous track to be provided. Thanks to [Tuomas Hämäläinen](https://github.com/tuomashamalainen) and [HiFiBerry](https://github.com/hifiberry) for reporting. This bugfix addresses issue [#972](https://github.com/mikebrady/shairport-sync/issues/972). + +Version 3.3.6d8 +==== +**Bug Fixes** +* Tidy up compilation of the `audio-dummy` and `audio-soundio` back ends when the `-fno-common` flag is used. +* Remove a superflous extra definition of a variable which would cause it to be used uninitialised. + +Version 3.3.6d7 +==== +**Bug Fix** +* Treat the `mper` (Persistent ID of a track) metadata attribute as the 64-bit item that it really is rather than a 32-bit item as hithereto. Output it as a hexadecimal number on the MPRIS and D-Bus interfaces to correspond with the format of the persistent id obtained from AppleScript. E.g: + +``` +tell application "Music" + get the {persistent ID} of the current track +end tell +``` +resulting in: +``` +{"FD84B4B40FA33A85"} +``` +The MPRIS `trackid` corresponding to this would be `/org/gnome/ShairportSync/FD84B4B40FA33A85`. + +Thanks to to [Scott Simon](https://github.com/zutroy97) for finding a related bug in the [shairport-sync-metadata-reader](https://github.com/mikebrady/shairport-sync-metadata-reader). + +**Other Changes** +* Include the `-fno-common` flag in the compilation options to detect incorrect definitions of global variables and multiple definitions of `enum` data types. + +Version 3.3.6d7 +==== +**Bug Fix** +* Make Shairport Sync compile in the forthcoming Fedora 32. Fedora 32 uses GCC-10 which [defaults to `-fno-common`](https://gcc.gnu.org/gcc-10/porting_to.html) exposing a number of issues with Shairport Sync – multiple definitions of some `enum`s and failure to define certain variables as `extern`. + + Version 3.3.6d7 is an attempt to clear up all these errors. Many thanks to [Bill Peck](https://github.com/p3ck) for his ongoing support, for bringing this issue to notice and for developing a workaround. Address issue [#973](https://github.com/mikebrady/shairport-sync/issues/973). + +Version 3.3.6d6 +==== +**Bug Fix** +* Add a `SIGCHLD` handler to remove completed processes that were used to perform and program "hooks" without waiting for completion and thus prevent them from becoming zombie processes. Thanks to [patrickjane](https://github.com/patrickjane) for reporting the bug and for suggesting a solution. Addresses issue [#968](https://github.com/mikebrady/shairport-sync/issues/968). + +Version 3.3.6d5 +==== +**Bug Fix** +* Fix an incompatibilty with Forked Daapd that was causing Forked Daapd to lock up. Thanks to [@tomgadow](https://github.com/tomgadow) and [@ejurgensen](https://github.com/ejurgensen) for their help in finding and (hopefully) fixing this issue. Addresses issue [#953](https://github.com/mikebrady/shairport-sync/issues/953) and [Forked Daapd Issue #870](https://github.com/ejurgensen/forked-daapd/issues/870). + +**Enhancements** +* Add some extra examples of using the RemoteControl interface's SetAirplayVolume feature to the shairport-sync-dbus-test-client source. + +**Pesky Changes You May Not Be Able To Ignore** +* Renamed the `Server` property in the D-Bus interface to `Client`. The rather strange language in use has it that a player like iTunes is a "client" of the AirPlay device like Shairport Sync, which is therefore considered the "server". The newly-renamed "Client" property is the IP number of the player. + +Version 3.3.6d4 +==== +A fix for issue #953 that wouldn't work. + +Version 3.3.6d3 +==== +**New Features** +* Add `SetAirplayVolume` to the native D-Bus `RemoteControl` interface. +* Add `SetVolume` to the `MPRIS` interface. + +**Bug Fixes** +* Hook up the `Volume` property in the `MPRIS` interface. + +**Enhancements** +* Modify `RemoteCommand` in the D-Bus interface to return the HTTP status and response in hex. +* Add a few sample commands, including `MPRIS` commands, to the [Sample D-Bus Commands](https://github.com/mikebrady/shairport-sync/blob/development/documents/sample%20dbus%20commands) document. + +Version 3.3.6d2 +==== +**New Features** +* Resampling has been added for the [Jack Audio](http://jackaudio.org) backend. This can be used to up-sample to 192kHz. Thanks to [Pieter De Gendt](https://github.com/pdgendt) for this addition. + +Version 3.3.6d1 +==== +This is release version 3.3.5. + +Version 3.3.5d1 +==== +**Pesky Changes You May Not Be Able To Ignore** +* Renamed the `LoudnessFilterActive` property in the D-Bus interface to `Loudness`. Updated [shairport-sync-dbus-test-client.c](https://github.com/mikebrady/shairport-sync/blob/development/shairport-sync-dbus-test-client.c) accordingly. + +**New Features** +* Added to the D-Bus interface the ability to turn on and off convolution, to set the convolution gain and to change the convolution impulse response files. See examples in [sample dbus commands](https://github.com/mikebrady/shairport-sync/blob/development/documents/sample%20dbus%20commands). Note: for these commands to make sense, Shairport Sync must be built with support for convolution and the native D-Bus interface (`--with-convolution` and `--with-dbus-interface`) and fully installed. + +**Bug Fix** +* Fixed a bug whereby if you enabled the Loudness filter via the D-Bus interface, the output disappeared until you changed the volume. + + +Version 3.3.5d0 +==== +**Bug Fix** +* Fixed a crashing bug when output format `"S24"` was chosen. Fixes the issue reported by [artenverho](https://github.com/artenverho) in [#927](https://github.com/mikebrady/shairport-sync/issues/927). + +Version 3.3.4 +==== +This version did not appear on the `development` branch -- it fixed a small compilation error. + +Version 3.3.3d11 +==== +**Bug Fix** +* Fixed a crashing bug -- if a plain HTTP packet (in fact, any packet that didn't have an RTSP-style header) was sent to the TCP session port (usually port 5000), Shairport Sync would crash! Thanks to @[dubo-dubon-duponey](https://github.com/dubo-dubon-duponey) for reporting. Fixes [#921](https://github.com/mikebrady/shairport-sync/issues/921). + +**Pesky Change** +* The setting `retain_cover_art` is now part of the `diagnostics` group. Set it to `"yes"` to retain cover art cached by the D-Bus, MPRIS or `mqtt` interfaces. Your directory may fill up if you leave it set! + +Version 3.3.3d9 +==== + +**Enhancements** +* Expose a `metadata` setting related to handling cover art: + * The setting `cover_art_cache_directory` allows you to specify where cover art files will be cached if Shairport Sync has been built with native D-Bus, MPRIS or MQTT support. The default is `/tmp/shairport-sync/.cache/coverart`. If you set it to an empty list: `""`, caching is disabled. This might be useful in, say, an embedded device, or wherever you want to minimise file writing. + +Version 3.3.3d8 +==== + +**Bug Fix** +* Fix a bug in the resend request logic. + + +**Enhancement** +* Expose the settings controlling the resend request logic. The new settings are in the `general` section: + * `resend_control_first_check_time` is the time allowed to elapse before a packet is considered missing, defaulting to 0.1 sec. UDP packets don't always arrive in order and they don't need to be re-requested just because they arrive out of sequence. Essentially, therefore, this parameter is to prevent needless resend requests for packets that are already in transit. + * `resend_control_check_interval_time` is the interval between repeated requests for a missing packet, defaulting to 0.25 seconds. + * `resend_control_last_check_time` is the time by which the last check should be done before the estimated time of a missing packet's transfer to the output buffer, defaulting to 0.1 seconds. In other words, if a packet is still missing 0.1 seconds before it is due to be transferred to the DAC's output buffer, don't bother asking for a resend. + + +Version 3.3.3d7 +==== + +**Duh** +* Versions 3.3.2d3 to 3.3.2d6 should have been labelled 3.3.3d\. + +**Enhancement** +* Rewrite the logic for identifying missing packets of audio and for asking for resends. It seems more robust -- there was a suspicion of the previous logic that resend requests were not made for some missing packets. In addition, requests for resends of continuous sequences of packets are rolled into one. + +Version 3.3.2d6 +==== +**Enhancements** +* Normalise the `'pvol`' volume outputs so that when both the software and hardware attenuators are in use to extend the overall attenuation range, the maximum output level corresponds to the maximum output level of the hardware mixer. +* Add the option of including the file and line number of each log entry's source. The option is on by default and is settable in the configuration file and in the `dbus` interface. + +**Bug Fixes** +* Fixes an error whereby the `'pvol'`volume metadata was no longer sent if Shairport Sync was configured to ignore volume control information coming from the audio source. Addresses issue [#903](https://github.com/mikebrady/shairport-sync/issues/903). Thanks to [Jordan Bass](https://github.com/jorbas) for reporting the regression and for identifying the commit and code in which the regression occurred. +* Fixes a compilation error if including the MQTT client -- thanks to [exoqrtx](https://github.com/exoqrtx) for reporting. +* Fixes a compilation error if including the MPRIS interface. +* Ensure the hardware mixer of an `alsa` device is detected and initialised before responding to the first volume setting. + +Version 3.3.2d5 +==== +**Enhancement** +* Improves the detection of the remote services available when an audio source is playing. If the source is minimally compatible, e.g. iOS, Shairport Sync's `org.gnome.ShairportSync.RemoteControl` native `dbus` interface becomes "`available`". If the source is iTunes, then the `org.gnome.ShairportSync.AdvancedRemoteControl` interface also becomes `available`. Artwork, metadata, status and limited remote control facilities are accessible through these interfaces when they are in the `available` state. Follows on from issues raised in [#890](https://github.com/mikebrady/shairport-sync/issues/890). Thanks again to [exoqrtx](https://github.com/exoqrtx) for bringing these issues to light and for testing. + +**Bug Fix** +* Fixes an issue that occured in Ubuntu 14.04 – the `shairport-sync` daemon would silently die after a fairly long period. It typically happened just after a DHCP address was renewed. The problem seemed to be related to having more than one `avahi` threaded polling loop (though this isn't documented anywhere). The fix was to consolidate the `avahi` stuff down to one threaded polling loop. Addresses issue [#895](https://github.com/mikebrady/shairport-sync/issues/895). Thanks to [Hans (the) MCUdude](https://github.com/MCUdude) for reporting and for initial troubleshooting. + +Version 3.3.2d4 +==== +**Bug Fixes and Enhancements** +* Fixes and enhancements to the MPRIS and native D-Bus interfaces. In particular, situations where artwork is absent are better handled, and the remote interface and advanced remote interface `availability` properties should be more resilient in the face of network problems. Addresses issue [#890](https://github.com/mikebrady/shairport-sync/issues/890). Thanks to [exoqrtx](https://github.com/exoqrtx) for bringing these issues to light and for testing. + +Version 3.3.2d3 +==== +**Bug Fix** +* Fixes a potential crash when an incomplete `fmtp` parameter set is sent by the requesting client. Thanks to [Angus71](https://github.com/Angus71) for the fault report and for the repair. + +**Enhancement** +* Instead of returning `EXIT_FAILURE`, return `EXIT_WITH_SUCCESS` on early exit with either "version" (`–version` or `-V`) or "help" (`–help` or `-h`) arguments. Thanks to [Henrik Nilsson](https://github.com/henriknil) for the patch. + +Version 3.3.2d2 +==== +**Bug Fix** +* Fix a double-free memory bug. Thanks to [Chris Boot](https://github.com/bootc) for reporting this bug, which came through the Debian BTS: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=925577. The fix is different from the suggested patch. + +Version 3.3.2d1 +==== +**Enhancements** +* Allow `disable_standby_mode` to operate on any output device, not just real hardware devices. If there are too many underruns while outputting silence, the disable standby mode will be turned off. + +The Inevitable Version 3.3.1rc1 +==== +**Bug Fixes** +* Fix a bug in the MQTT documentation and add sanity checking for the port chosen -- thanks to [David Crook](https://github.com/idcrook). +* Fix a bug that caused manual format and rate setting to be ignored -- thanks to [Jörg Krause](https://github.com/joerg-krause). +* Add missing support for format settings S24_LE, S24_BE, S32_LE and S32_BE. +* Fix a bug that caused dither to be too loud. +* Fix error message for invalid `disable_standby_mode` choice -- thanks to [Tim Curtis](https://github.com/moodeaudio) at [Moode Audio](https://moodeaudio.org). + +Version 3.3rc8 +==== +**Enhancements** +* Add a list of alsa hardware devices found to the alsa backend help section in the `shairport-sync -h` text. (Doesn't work for alsa on FreeBSD/OpenBSD.) +* Always place D-Bus access policy documents in `/etc/dbus-1/system.d` in Linux, but adhere to the standard for FreeBSD/OpenBSD. + + +Version 3.3rc7 +==== +**Enhancements** +* Improvements to the `MQTT` client -- extra diagnostic messages at run time and at configuration time. + +Version 3.3rc6 +==== +**Pesky Change You Can't Ignore** +* The `while_active` setting in the new `disable_standby_mode` has been renamed to `auto`. + +**Enhancements** +* Automatic bit-depth and speed selection for `alsa` output devices has been added and is the default. The greatest bit depth available is selected, and the lowest multiple of 44,100 frames per second is chosen. +* Improve support for big-endian devices by adding support for `S16_LE`, `S16_BE`, `S24_LE`, `S24_BE`, `S32_LE` and `S32_BE` formats. + +Version 3.3rc5 +==== +* Had a bug, sorry -- please go to 3.3rc6 or later. + +Version 3.3rc4 +==== +**New Feature** +* Support is now included for the automatic selection of the interpolation method. If support for `soxr` interpolation is included at configuration time (using the `--with-soxr` at the `./configuration...` step), then `auto` interpolation is made the default interpolation mode. During startup, the time it takes to do two `soxr` interpolations is calculated -- this, in milliseconds, becomes the `soxr_delay_index`. If the `soxr_delay_index` is less than or equal to a new `general` group setting called `soxr_delay_threshold` (default 30), then `soxr` interpolation will be chosen in `auto` mode; otherwise, `basic` interpolation will be chosen. + +Version 3.3rc3 +==== +**Minor Enhancement** +* Calculate the length of the first sequence of frames of silence preceding the audio at the start of a play session a little more carefully to make it somewhat longer. This should make output devices that operate with a fairly large buffer a little less likely to underrun at the start of a session. + +Version 3.3rc2 +==== + +**New Feature** +* Shairport Sync can now accept AirPlay streams containing uncompressed PCM -- specifically, 16-bit network-endian interleaved stereo, 44,100 frames per second. There is a restricton -- the packets of audio must be 352 frames long. + +**Bug Fix** +* Compatibility has been restored with virtual ALSA devices. Sometimes, an ALSA output device isn't actually a real hardware device -- for example, if PulseAudio is installed in your system, the "default" ALSA output device may in fact a virtual device that provides a route into the PulseAudio sound server for audio from ALSA-compatible applications. Such virtual devices don't always provide the precise delay timing that Shairport Sync uses. The bug fix is to fall back to the standard calls when precise delay timing is not available. +* If precise delay timing data is not available, the `disable_standby_mode` is turned off, as it relies on high precision timing. + +Version 3.3rc1 +==== + +**New Feature** +* If support for `soxr` interpolation is included at configuration time, then `soxr` interpolation is made the default at run time. (This was later changed -- see 3.3rc4.) +* If support for the Apple ALAC decoder is included at configuration time, then the Apple ALAC decoder is made the default at run time. +* If support for metadata is included at configuration, then metadata and cover art are both enabled by default at run time. +(Metadata is enabled if you configure support for metadata, the dbus interface, the MPRIS interface or the MQTT client.) + +**Enhancements** +* MQTT publishes `active_start` and `active_end` events when the active state is entered and exited. +* Add correction to fix for tinysvcmdns CVE-2017-12130. +* Partly update man pages. + +Version 3.3rc0 +==== + +Version 3.3rc0 is 3.3d56 + +Version 3.3d56 to Version 3.3d40 +==== +**New Features** +* Two new external program/script hooks – `run_this_before_entering_active_state` and `run_this_after_exiting_active_state` are provided for when the system goes active or inactive. Background: Many users use the `run_this_before_play_begins` program hook to turn on an amplifier and the `run_this_after_play_ends` hook to turn it off. A big problem is when another play session starts immediately after a play session ends, causing the amplifier to be switched off and then on again very quickly. This happens, for example, when a YouTube clip ends and the next one begins. To get around this, the concept of an *active state* covering a sequence of play sessions is introduced. When a play session starts, the system goes active, i.e. it enters the active state. When the play session ends, the system remains active for a period determined by the `active_state_timeout` setting, 10 seconds by default. If another play session starts before the period elapses, the system stays active; otherwise the system goes inactive -- it leaves the active state. The two new hooks mentioned above can be used to execute programs/scripts when the system goes active or inactive. +* A new `alsa`-only `disable_standby_mode` setting, for controlling the Disable Standby feature, can be set to `always`, `while_active` or `never`. The `always` setting is recommended for systems where the output device is dedicated to Shairport Sync. The "Disable Standby" state iself can be set or cleared via the D-Bus interface `DisableStandby` property. +* A new command-line option, `-u`, directs logging to STDERR rather than the system log. Useful when you compile Shairport Sync without `libdaemon` using the `--without-libdaemon` configuration option. + +**Enhancements** +* Changes to the Jack Audio back end. The back end for Jack Audio, `audio_jack.c`, has been extensively rewritten by [Jörn Nettingsmeier](https://github.com/nettings) in a way that is more in keeping with the Jack Audio style. It uses native Jack Audio lockless buffers and offers autoconnect facilities that the previous version didn't have. Many thanks to him. +* The volume-control software has been completely rewritten. From a user's point of view, the result should be a much smoother response to volume control changes, free from artefacts. It is now also possible to combine the hardware mixer and the software attenuator in two ways -- giving priority to the software mixer or giving priority to the hardware mixer. see the new `volume_range_combined_hardware_priority` setting in the `general` section opf the configuration file. +* The muting/unmuting code has been rewritten to be simpler and more consistent. +* In the `alsa` backend, new `play()` and `delay()` functions minimise the use of `snd_pcm_recover()` to prevent unnecessary resets of the output DACs. +* In the `alsa` backend driver, hardware isn't accessed until the first time it is needed. That is, when Shairport Sync starts up, it no longer needs to access the device momentarily. Instead, it waits for the first use. +* The `libdaemon` library is now an optional build. It is not necessary for `systemd` systems and can be omitted. Use the `--without-libdaemon` configuration option to leave it out. + +**Bug Fixes** +* The `mdns-external` method used to advertise the Shairport Sync AirPlay service on ZeroConf is now an optional build and is omitted by default. Previously it was included with `--with-avahi` and could not be included on its own. +* A number of memory leaks associated with the use of OpenSSL have been fixed. +* Use CLOCK_RUNTIME in place of CLOCK_MONOTONIC when doing synchronisation timing using the alsa library prior to 1.0.28. Necessary for compabibility with OpenWRT Barrier Breaker. + +Version 3.3d39 to Version 3.3d38 +==== + +**New Feature** + +A new feature called *Disable Standby* keeps the output DAC in the play state all the time and helps to remove some annoying clicking / popping noises. It is really pretty impressive, especially combined with fixes to the dithering code described below. If you can enable 24- or 32-bit audio output to your output device, you can get even better results. + +This is an ALSA-specific attempt to remove the annoying low-level clicking sounds that some output devices make just when they start processing audio and sometimes when they stop. Typically a faint click might be heard just before a play session starts or just before audio resumes after a pause. Similarly, a faint click can sometimes be heard just after a play session ends. + +It is extremely difficult to remove these clicks completely from the hardware, so this new feature ensures that the output device avoids situations where these clicks might be generated by *always* playing audio. To accomplish this, if Shairport Sync isn't actually playing anything, audio frames consisting of silence are sent to the output device, keeping it playing. Apart from the initial startup transition, the output device never stops playing and thus never transitions to and from standby mode, avoiding the possibility of generating associated audio disturbances. + +To enable this feature, a new `alsa` group setting with the name `disable_standby_mode` is available. (If you do a full `$ sudo make install`, a new sample configuration file with this setting in it is installed at `/etc/shairport-sync.conf.sample` or `/usr/local/etc/shairport-sync.conf.sample`.) + +A downside to this feature is that the output device totally dedicated to Shairport Sync. For this reason, this new feature is disabled by default. + +Note -- this setting is likely to change. It will probably be necessary to modify it somehow to enable it to be used in integrated systems. Your feedback would be welcome. + +**Enhancements and Bug Fixes** + +* At present, Shairport Sync adds dither to the audio (a) if the built-in software-based volume control is used, (b) if the audio is mixed to mono or (3) if there is a reduction in sample size, say from 16- to 8-bit. The code for generating dither has been much improved. Due to a poor pseudo-random number arrangement, the dither noise didn't sound like white noise -- now it does. In addition, if dither is to be added, it is also added to the silence inserted just prior to the start of play, and is also added to the silent frames used to prevent the output device from going into standby mode, if selected. + +Version 3.3d37 to Version 3.3d22 +==== + +These updates are about stability. + +**Enhancements and Bug Fixes** + +With great help from [gibman](https://github.com/gibman) — see [#772](https://github.com/mikebrady/shairport-sync/issues/772) for the gory details — a myriad of issues have been identified and fixed. In particular, [gibman](https://github.com/gibman) shared an automated way of stress-testing Shairport Sync, and this has resulted in the detection of many bugs. + +And so, with apologies to Shakespeare, we have taken up arms against a sea of troubles, and by opposing we have ended them. It is hoped that the result is considerably more stable and can better withstand the, uh, slings and arrows of outrageous fortune. + +Here is a flavour of some of the issues addressed: +* Replace the existing watchdog, which only offered partial coverage, with a much more robust thread-based watchdog. +* Allow a reported remote processing time of zero. +* Fix a logical error that could cause an endless loop during a flush. +* Ensure a player thread is correctly initialised before allowing it to be cancelled cleanly. +* Ensure the player thread always has a cancellation point so that it should always be possible to ask it to terminate. +* If a play session is interrupted, wait for it to terminate for up to three seconds. +* If a play session is interrupted, ensure the new session uses a different set of UDP ports. This is to ensure that data from the interrupted session – which might be still in transit – doesn't enter the new session. +* Make all ALSA command sequences un-cancellable. This is to ensure that ALSA subsystem will not be left in a partially-initialised state if Shairport Sync terminates abruptly. +* When a connection is terminated abruptly, ensure that all the UDP ports is use are closed properly. +* Impose timeouts on both reading and writing to the supervisory RTSP connection governing a session. +* When closing the RTSP connection due to an error, close it immediately, without waiting for a full TCP handshake, because, if the other end has erred, the handshake may never come. +* Fix a parameter initialisation error in a situation where there is no hardware mixer. +* Fix an MQTT-related crash by ignoring unrecognised commands. +* Fix a compilation error and a warning when using the `--with-convolution` configuration option. + +**New Feature** +* A new `run_this_if_an_unfixable_error_is_detected` (in the `sessioncontrol` group of settings) program hook is provided. At the moment, two conditions can trigger this. The first is if the watchdog is unable to terminate a play session. The second is if the output device stalls for a long period. Both conditions can be caused by malfunctioning DACs. The external program could, for example, reboot the device. + +Version 3.3d21 +==== +**Enhancements** +* Use `/dev/urandom` rather than `/dev/random` as a source of some kind of randomness for the cryptographic "nonce" used in AirPlay password exchange, as `/dev/random` blocks occasionally. Please see [here](https://unix.stackexchange.com/questions/324209/when-to-use-dev-random-vs-dev-urandom) for a discussion of the merits of both. The effect of `/dev/random`'s blocking on Shairport Sync was to make the source of randomness somewhat less random. (By the way, you should never use an important password as an AirPlay password for Shairport Sync -- it is stored in Shairport Sync's configuration file in plain text.) + +Version 3.3d20 +==== +**Enhancements** +* The code that deals with packet loss resulting from network problems has been completely rewritten. The reason is that, while the old code worked quite well, it could be overwhelmed if the network problems were very serious. The new code is simpler and more robust in testing so far. This code interacts with the code for flushing audio before and after a play session, so it may have introduced regressions. +* The build instructions have been changed to avoid compiler warnings coming from automatically-generated code produced for the D-Bus-based interfaces. +* Warnings are now logged if the ALSA subsystem fails to recover properly after an error has been cleared. + +**Bug Fix** +* A compilation problem in OpenBSD has been fixed by changing the order of some include files. + +Version 3.3d16 +==== +**Enhancement** +* Extend the range of `audio_backend_latency_offset_in_seconds` to ± 1.75 seconds. Note that no sanity checking of any kind is done on this – if it is too large the program may simply crash. + +* Pay more attention to errors that may occur when asking for the DAC delay just before play starts. For diagnostic use. + +* Formatting of the settings file `shairport-sync.conf` has been fixed, thanks to the work of [roblan](https://github.com/roblan). + +Version 3.3d15 +==== +**Enhancement** +* Adjust the latency calculation to accommodate changes in iOS 12 and AirPlay connections from macOS Mojave. Thanks to [artenverho](https://github.com/artenverho) who first reported the issue. + +Version 3.3d14 +==== +**Bug Fix** +* Fix a problem when calling the program to be run when the volume control is changed. Thanks to [shaven](https://github.com/shaven) for the report. + +Version 3.3d13 +==== +Reverted to 3.3d11 -- the modification in 3.3d12 was not needed and has been removed. + +Version 3.3d11 +==== +**Enhancement** +* Add a configuration option to specify the PulseAudio output sink. An extra option for the `pa` backend to allow the specification of the audio sink. Thanks to [Maciej Wilczyński](https://github.com/mLupine) for his work on this. + +**Bug Fix** +* Remove unrecognised options from FreeBSD and OpenBSD compilation instructions. + +Version 3.3d10 +==== +Modify the `jack` interface to ignore the latencies of any ports connected to the `jack` end. This is because it does not seem appropriate to try to compensate for the delays in the `jack` system. Not sure if this is the correct approach... Maybe it's better to allow the user to select no compensation, compensate for the lowest latency or compensate for the highest latency; it seems unnecessarily complex, not really the business of Shairport Sync. + +Version 3.3d9 +==== +Many changes to compilation and linking flags. Stop using `HAVE_*` flags except where necessary, use `CONFIG_*` for optional stuff, use `HAS_*` for immediate definitions to be used during configuration, use `USE_*` for Automake definitions. Probably introduced bugs, sigh. + +Version 3.3d8 +==== +**Bug Fix** +* Ensure the compiler flag `HAVE_LIBSOXR` is defined if the `--with-soxr` configuration flag is used and `pkg-config` is in use. + +Version 3.3d7 +==== +* Remove the "rolling" requirement for Jack output to be sent. +* Set the default buffer size for Jack to 0.5 seconds. This may be temporary! + +Version 3.3d6 +==== +An improved [Jack Audio](http://jackaudio.org) backend. Testing notes: +* At the `./configure` step, include `--with-jack`. This should not require any extra packages or libraries when it is being compiled on an AVLinux machine. No need for any other backend to be included, so you can omit `--with-alsa`, etc. +* Tested on the latest AVLinux only. +* Jack Audio will not run correctly on a virtual machine; it will only work properly on a real device. +* A new set of configuration options is present in the configuration file. +* The Shairport Sync backend will attempt, every second, to open a client on the Jack server until it succeeds. This behaviour can be stopped or the interval extended with the `jack` `auto_client_open_interval` configuration option. +* Once a Jack client has been opened by the Shairport Sync backend, it will remain open. This behaviour can be changed with the `jack` `auto_client_disconnect` configuration option. +* Other Jack congfiguration options include the ability to change the name of the client – `client_name` – and the names of the channels – `left_channel_name` and `right_channel_name`. + +Testing needed -- these arrangements may not conform to the norms of the Jack community, so all feedback gratefully received. + +Some information, e.g. the true output rate, not implemented yet. + +Version 3.3d5 +==== +* Introducing a very rough implementation of a Jack Audio backend. The JACK Audio Connection Kit "provides a basic infrastructure for audio applications to communicate with each other and with audio hardware. Through JACK, users are enabled to build powerful systems for signal processing and music production." + +Version 3.3d4 +==== +* Sometimes `libsoxr` is built to rely on `libavutil`. With the present changes to `configure.ac`, if `libavutil` is present, link to it when linking to `libsoxr`, but if it's not present, don't link to it when linking to `libsoxr`. +* Add `pgk-config` support to `libsoxr` selection. + +Thanks to [Jörg Krause](https://github.com/joerg-krause) for identifying these issues and proposing fixes. + +Version 3.3d3 +==== +* Modify the code that synchronises the Shairport Sync system's clock with the source clock to try to take account of the sources's nominal rate, which (oddly, e.g. iTunes on a Mac) might not be exactly 44,100 fps. There may be a 32-bit unsigned overflow error here somewhere! + +* Try to interpolate for the measured drift between the standard three-second timing snapshots. These changes make a very slight difference from time to time, of the order of microseconds, and it's not clear yet how reliable the drift interpolation is. + +* Add some extra fields to the `statistics` output, including nominal source rate, actual input rate, actual output rate, source clock drift, calculated correction needed in ppm. All these numbers agree to a high degree, but the generation of them is fragile and susceptible to errors when there are problems like underrun, and they are not actually running averages, which would be genuinely useful. But they show promise! + +**Bug Fixes** +* Fix a bug in the `dbus` native interface which would silently switch `soxr` interpolation to `basic`. +* Fix a mutex lock bug in the metadata hub. No known effects. + +Version 3.3d1 +==== +Internal changes are being made for version 3.3 to avoid using `SIGUSR1` and `pthread_kill` to stop threads; the standard `pthread_cancel` and friends are being used instead. This should lead to more reliable and orderly cancellation of sessions and threads. However, it is quite a complex change, so bugs may have been introduced or reactivated. Lots of testing needed. + +**Bug Fix** +* Fix an arithmetic overflow in frame rate calculations that could occur after 2^32 frames – approximately 27 hours at 44,100 frames per second. + +Version 3.3d0 +==== + +**New Features** +* Frame rates! Exact input and output frame rates are now included in the `statistics` output. The figures generated are averaged over the entire play session since the last pause/resume, if any, so they should settle down and become more accurate over a long play session, say a couple of hours. Timing is relative to `CLOCK_MONOTONIC`. When your system is connected for an appreciable period to network time, e.g. using an NTP client, `CLOCK_MONOTONIC` is adjusted ("conditioned") to keep time extremely accurately. The calculated output frame rate should be very accurate. The calculated input frame rate will vary considerably over short intervals due to network conditions, but over a long play session it should also become very accurate. +Timing is done from the start of the play session, or from the resumption of play following a pause. Note that while some audio sources pause and resume between tracks, both iTunes on the Mac and the Music app on iOS play all the tracks on a playlist without pause (so long as the tracks are downloaded and present in the device in time). +* Add the command `quit` to the MPRIS and the D-Bus interfaces. The main motivation for this is that it makes it easier to search for memory leaks. + +**Bug Fixes** +* A number of memory leaks have been identified and removed. +* A bogus warning about using the deprecated `general` `statistics` options has been fixed. + +Version 3.2d67 +==== +This is equivalent to 3.2.1. + +**Bug Fix** +* Fix a bug causing a crash when `soxr` interpolation was enabled and a play session was stopped. This bug overwrote incorrect memory locations, so depending on what it overwrote, may have been responsible for other inexplicable crashes. Thanks are due to [hanaguro](https://github.com/hanaguro), [FnasBas](https://github.com/FnasBas), [priitohlo](https://github.com/priitohlo), [David Krmpotić](https://github.com/davidhq) and [artenverho](https://github.com/artenverho). + +Version 3.2.d66 +==== +This is equivalent to 3.2. + +Version 3.2.d65 +==== +**Modification** +* The algorithm for generating resend requests has been made somewhat more gentle -- a little less insistent. + + +**Bug Chasing** +* Some very elementary bounds checking on the ANNOUNCE packet is performed: that it is 1024 bytes or less in size and that line lengths remaining after parsing do not turn negative when they should remain positive or be exactly zero. + +Version 3.2.d64 +==== +**Enhancement** +* An extra property has been added to the RemoteControl section of the native Shairport Sync D-Bus interface. It is the "progress" metadata emitted from time to time by the AirPlay source and consisting of RTP timestamps for the start of the current play sequence, the current play point and the end of the play sequence. + +**Bug Fix** +* Code to monitor the amount of time a mutex lock request took is improved. + +Version 3.2.d63 +==== +**Enhancement** +* An [MQTT](https://en.wikipedia.org/wiki/MQTT) client interface is introduced, with support for metadata and for some remote control commands, thanks to the work of [Till Zimmermann](https://github.com/tillz). MQTT is a fairly often used protocol in FOSS home-automation projects (as well as in commercial ones), and as Shairport Sync is often used in these setups, this adds client support for this protocol. + +Version 3.2d62 +==== +**Bug Fix** +* Restore compatibility with Synology AudioStation/5.2. Thanks to [Jörg Krause](https://github.com/joerg-krause) for identifying both the issue itself and the likely location of the fix needed. It's not clear if the problem lies with Shairport Sync or Synology – the fix was to ensure that an RTSP reply was sent in one `SEND` call, which shouldn't be important. + +Version 3.2d61 +==== +**Bug Fix** +* Add a pthread_cancel cleanup routine to put_packet to unlock the player rw mutex when cancelled. Sincere thanks to [David Krmpotić](https://github.com/davidhq) for help investigating this. + +Version 3.2d57, 3.2d58, 3.2d59, 3.2d60 +==== +**Bug Chasing** +* Debug messaging has been enhanced when a `TEARDOWN` message is received. +* Check both timed and untimed mutex locks and give estimates of how long to wait. Generate debug messages when appropriate. +* Unlock the `ab_mutex` when sending a resend request. + +Version 3.2d56 +==== +**Enhancement** +* The `mute_using_playback_switch` setting in the `alsa` group has been replaced by a `use_hardware_mute_if_available`, which defaults to `"no"`. This new setting controls both the playback switch method and the magic volume level method for doing hardware-supported muting. +If hardware muting is used, the output device will be muted when Shairport Sync releases it, potentially causing problems for other audio programs using the device. To avoid this, `use_hardware_mute_if_available` is disabled by default. + +**Bug Chasing** +* A debug message has been enhanced when a `TEARDOWN` message is received. + +Version 3.2d55 +==== +**Bug Fix** +* Flush requests that are received while the player is being initialised or deleted are now ignored. This should prevents two potential (but never seen) lock possibilities. + +Version 3.2d54 +==== +**Bug Fix** +* Prevent packets of audio being added when the play session has ended and the player is being deleted. They are now simply dropped. + +Version 3.2d53 +==== +**Bug Fix** +* Fix an incompatibility with Cygwin 64. It seems that the handling of signals in Cygwin is different to regular "native" Unix/Linux platforms. So, this is an attempt to use `pthread_cancel` calls where possible. In principle it should simplify thread management considerably, so let's see how it goes. +* Fix an off-by-one error that was generating excessive resend requests. + +Version 3.2d51 +==== +* Fix a small bug locking and unlocking the read-write mutex. It might (and in principle, it could) cause a crash. + +Version 3.2d50 +==== +* Add a read-write mutex lock to the player thread so that it can't be accessed while it's being created and initialised or while it's being torn down and destroyed. Make external accessor functions acquire a read lock for access. It's "A Good Thing" and it might help the seg fault problem, which I'm afraid still can't reproduce... + +Version 3.2d49 +==== +* A few extra debugging messages to try to locate where a segfault is occurring. + +Version 3.2d48 +==== +**Bug Fix** +* A seg fault possibly caused by a dangling pointer has been addressed by making the UDP sockets blocking rather than non-blocking. A two millisecond limit has been put on the sendto calls. + +Version 3.2d47 +==== +**Bug Fix** +* A very subtle bug that would occasionally cause a loud 80 millisecond buzz when a new track was selected has been located and fixed. Thanks to [mistipen](https://github.com/mistepien) and [artenverho](https://github.com/artenverho) for help with this. + +Version 3.2d46 +==== + +Update [TROUBLESHOOTING.md](https://github.com/mikebrady/shairport-sync/blob/development/TROUBLESHOOTING.md) to correspond to 3.2RC6. + +Version 3.2d45 +==== +**Enhancement** +* Restore the old method for calculating latency for older AirPlay sources: an AirPlay source displaying an AirPlay User Agent string version of 353 or older -- corresponding to iOS 11.1.2 or older -- will add an extra 0.25 seconds to the latency requested. This seems to be right. + +Version 3.2d44 +==== +**Bug Fixes** +* When errors occur sending resend requests, back off for 0.5 seconds, rather than 10 seconds, and make the code actually work. +* Make the configuration options for including the dbus interface and the mpris interface be `--with-dbus-interface` and `--with-mpris-interface` as expected, not `--with-dbus` and `--with-mpris` as they actually were. + +Version 3.2d42 +==== +This version just brings some small changes made to the Release Candidates back into the `development` branch. + +Version 3.2d41 +==== +**Bug Fixes** +* Fixed a hitherto-silent bug that prevented Shairport Sync working properly with AirAudio. According to the [unofficial standard](https://nto.github.io/AirPlay.html), requests for resending missing packets come from the control port; however, up until now, Shairport Sync sent them on the audio port. All AirPlay sources responded to these improperly-delivered requests except AirAudio, which discards requests that do not come from the correct source. Fixed now, with many thanks to [funtax](https://github.com/funtax) and to [Janusz Kowalczyk](https://github.com/kowalcj0) for bringing the issue to the fore. + +Version 3.2d40 +==== +**Bug Fixes** +* A number of serious and long-standing bugs have been identified and fixed in the threads that handle audio, control and timing packets. Specifically, if UDP reception or transmission errors occurred (a rare occurrence on a good network, but possible on noisy or congested networks), the threads would quit. In this way, an error on the reception of the first control packet could mute an entire play session. + +**Enhancements** +* The code used to request the retransmission of missing audio packets has been significantly improved. + +Version 3.2d39 +==== +**Enhancements** +* An extra diagnostic to artificially drop UDP packets to simulate a noisy network has been added. Set the proportion of packets to be dropped in the `diagnostics` section of the configuration file using the tag `drop_this_fraction_of_audio_packets`. The value should be between 0.0 and 1.0. E.g. a value of 0.001 would mean one packet in a thousand would be dropped, on average. Look in the sample configuration file `/etc/shairport-sync.conf.sample` for the added entry. +* Minimal compatibility with AirAudio has been added / restored. There remains a question about error correction for handling UDP packet loss. Thanks to [Janusz Kowalczyk](https://github.com/kowalcj0) for reporting the issues. + +Version 3.2d35 +==== +**Enhancements** +* More cleaning up of the D-Bus and MPRIS interface messages -- they are quieter now. + +**Bug Fix** +* Thanks are due to [yejun](https://github.com/yejun) for noticing and proposing a fix for the bug that dithering is left on when the volume control is ignored. Audio samples should pass through without alteration. (The fix was already in the `development` branch though.) + +Version 3.2d34 +==== +**Enhancements** +* Better compatibility with TuneBlade -- Shairport Sync honours the latency settings properly now. +* Big cleanup of D-Bus and MPRIS interface messages -- it's a lot less noisy. More to be done here. +* The brokey YouTube iOS app, which generates a great deal of invalid metadata (do they even know?), is handled a bit better. If valid metadata is there, Shairport Sync can process it. +* `clip` and `svip` messages are now only emitted for a play connection, not for all connections (e.g. connections that just enquire if the service is present). +* `pfls` and `prsm` messages are less frequent, especially when a play session starts. + +**Other Developments** +* Shairport Sync now uses about an extra half megabyte of RAM for compatibility with TuneBlade's option to have a very long latency -- up to five seconds. + +Version 3.2d33 +==== +A new metadata token -- `'pffr'` -- is emitted when the First Frame of a play session has been Received. Not sure we'll keep it... + +Version 3.2d30 +==== +**Enhancements** +* A "native" D-Bus Remote Control permits remote control of the current AirPlay or iTunes client. It includes status information about whether the remote control connection is viable or not, i.e. whether it can still be used to control the client. +A remote control connection to the audio client becomes valid when the client starts AirPlaying to Shairport Sync. The connections remains valid until the audio source deselects Shairport Sync for AirPlay, or until the client disappears, or until another client starts AirPlaying to Shairport Sync. It is likely that a time limit will be put on this, so that after, say, 30 minutes of inactivity, the remote control connection will be dropped. + +Version 3.2d29 +==== +**Enhancements** +* CAR INSTALL and OPENBSD notes added. +* A barebones "native" D-Bus interface for Shairport Sync permitting control of some diagnostic settings. To be expanded... +* A partly implemented MPRIS control interface including play/pause/next/previous/volume and some metadata. +* Remote control of an iTunes source including play/pause/next/previous/volume. +* Remote control of an AirPlay source including play/pause/next/previous. + +Version 3.2d28 +==== +Continuing the experiments with D-Bus and related DACP support. In this revision, an attempt is made to control the amount of scanning the system does to maintain up-to-date information about a DACP source. As before, please note that the implementation is likely to change greatly or be removed at any time. + +**Enhancements** +* Barebones support added for OpenBSD compilation. +* Only ask for missing packets to be resent once, and if any error occurs making the request, stop for 10 seconds. +* Include the `-pthread` flag -- including the pthread library with `-lpthread` isn't always enough. + +Version 3.2d26 +==== + +**Enhancements** +* Improvements in the documentation relating to scripts -- thanks to [Niklas Janz](https://github.com/Alphakilo). +* Add optional timing annotations to debug messages -- see the new settings in the diagnostic stanza of the configuration file. + +**Bug Fixes** +* Ensure the TEARDOWN of a play session is not delayed by a long sleep timer. +* Allow more than one ANNOUNCE packet for the same play session. Honour the settings in the most recent one. +* Move the creation and calling of a player thread from the SETUP handler to the RECORD handler. +* When closing an ALSA sound device, don't wait for any remaining audio to be output with `snd_pcm_drain`; instead, just drop all remaining frame using `snd_pcm_drop`. +* TEARDOWN should complete in less than 50 ms. + +Version 3.2d25 +==== +**Enhancement** +* Better handling of missing timing packets. +* Improved resnchronisation logic should improve performance with slow-to-download YouTube videos. +* Shairport Sync will now log an unexpectedy dropped or faulty RTSP connection. This might be useful on noisy networks. + +Version 3.2d24 +==== +**New Feature** +* A new `general` option `volume_control_profile`, for advanced use only, with two options: `"standard"` which uses the standard volume control profile -- this has a higher transfer profile at low volumes and a lower transfer profile at high volumes -- or `"flat"` which uses a uniform transfer profile to linearly scale the output mixer's dB according to the AirPlay volume. + +Version 3.2d23 +==== +Continuing the experiments with D-Bus and related DACP support. + +**Enhancement** +* Some DACs have a feature that the lowest permissible "attenuation" value that the built-in hardware mixer can be set to is not an attenuation value at all – it is in fact a command to mute the output completely. Shairport Sync has always checked for this feature, basically in order to ignore it when getting the true range of attenuation values offered by the mixer. +However, with this enhancement, Shairport Sync can actually use this feature to mute the output where appropriate. + +Version 3.2d22 +==== +Continuing the experiments with D-Bus and related DACP support. + +**Bug Fix** +* Fix timing error when using Airfoil as a source. + +Version 3.2d21 +==== +Continuing the experiments with D-Bus and related DACP support. In this revision, [tinyhttp](https://github.com/mendsley/tinyhttp) is now used for sending and retrieving DACP information. Many thanks to [Matthew Endsley](https://github.com/mendsley) for this work on tinyhttp. +As before, please note that the implementation is likely to change greatly or be removed at any time. + +Version 3.2d20 +==== +**Bug Fix** +* Fix silly seg-fault bug in 3.2d19, activated when a DACP record was withdrawn. + +Version 3.2d19 +==== +**Enhancement** +* Add compatibility with [Swinsian](https://swinsian.com), a Mac music player. + +Version 3.2d18 +==== +**Bug Fix** +* In recent versions of iOS (11.2) and mac OS (10.13.2), when play is resumed after a pause, the volume level is not always restored, and, if software volume control is being used, Shairport Sync plays at full volume. This issue has been addressed by storing the last airplay volume setting when a play session ends and using it as a default when a new play session begins. (This is a more generalised solution than in 3.2d16.) +* Better AirPlay synchronisation. Older versions of Shairport Sync added an 11,025 frame (0.25 seconds) offset to all the latencies agreed with the sender. This seems now only to be correct for iTunes and ForkedDaapd sources, but incorrect for AirPlay sources. Accordingly, the offset is only added for iTunes and ForkedDaapd. The result is better sync with videos, e.g, YouTube, etc. while iTunes and ForkedDaapd synchronisation is unaffected. + +Version 3.2d16 +==== +**Bug Fix** +* In recent versions of iOS (11.2) and mac OS (10.13.2), when play is resumed after a pause, the volume level is not always restored, and, if software volume control is being used, Shairport Sync plays at full volume. This issue has been addressed by storing the last software volume setting when a play session ends and using it as a default when a new play session begins. + +Version 3.2d15 +==== +**Bug Fix, kind of...** +* Shairport Sync crashes on Arch Linux with with pulseaudio backend enabled. The cause appears to be a pulseaudio configuration issue, but of course, Shairport Sync shouldn't crash. For the present, the bug fix merely adds an error message before terminating Shairport Sync. + +**Enhancements** +* Still lots of changes and experiments with D-Bus and DACP. As before, please note that the implementation is likely to change greatly or to be removed at any time. + +Version 3.2d13 +==== +**Security Update** + +The version of `tinysvcmdns` bundled in Shairport Sync has a buffer overflow bug: *"An exploitable heap overflow vulnerability exists in the tinysvcmdns library version 2016-07-18. A specially crafted packet can make the library overwrite an arbitrary amount of data on the heap with attacker controlled values. An attacker needs send a dns packet to trigger this vulnerability."* The vulnerability is addressed by additional checking on packet sizes. See also [CVE-2017-12087](https://bugs.launchpad.net/bugs/cve/2017-12087) and [Vulnerability in tinysvcmdns](https://bugs.launchpad.net/ubuntu/+source/shairport-sync/+bug/1729668). +Thanks and [Chris Boot](https://github.com/bootc) for fixing this bug. + +Version 3.2d12 +==== +Experimenting with an [MPRIS](https://specifications.freedesktop.org/mpris-spec/latest/)-compatible D-Bus interface. A very small number of features have a tentative implementation. As with the Shairport Sync D-Bus interface, please note that the implementation is likely to change greatly or be removed at any time. + +Continuing the experiments with D-Bus support, Shairport Sync can now be compiled to have a D-Bus presence on the D-Bus system bus. It presents a small number of properties and can execute a method call which sends a command string to the audio source's DACP port. As before, please note that the implementation is likely to change greatly or be removed at any time. + +**Enhancement** +* The metadata output stream can include a `dapo` message carrying the DACP port number to be used when communicating with the DACP remote control. This might be useful because the port number is actually pretty hard to find and requires the use of asynchronous mdns operations. You must be using the Avahi mdns back end. + +**Bug Fix** +* A bug in the hardware volume control affects output devices that have hardware mixers but that do not allow the volume to be set in dB. One example is the Softvol plugin in ALSA. Shairport Sync fails silently when presented with such a device when hardware volume control is enabled: the volume events have no effect. The bug has been fixed by adding two missing lines of code to the `init()` function in `audio_alsa.c`. Thanks to [Jakub Nabaglo](https://github.com/nbgl) for finding and fixing the bug. +* A number of bug fixes due to [belboj](https://github.com/belboj). Many thanks for these! +* Enhancements to the handling of quit requests by threads, thanks(again) to [belboj](https://github.com/belboj)! + +**Other Stuff** +* The directory structure has been rearranged somewhat. Probably will change again... +* Typo fix! Thanks to [corbinsantin](https://github.com/corbinsantin). + +Version 3.2d8 +==== + +**Bug Fix** +* Fixed a bug that prevented Shairport Sync from starting automatically on systems using the System V startup system (e.g. Ubuntu 14.04). The problem was that the directory to be used – `/var/run/shairport-sync/` – was deleted on power down and needed to be recreated on startup. In it's absence, Shairport Sync would not start and would report a mysterious daemon error \#2. + +Version 3.2d7 +==== +This introduces a very experimental [D-Bus](https://en.wikipedia.org/wiki/D-Bus) interface to Shairport Sync. At present, in a very ad-hoc trial arrangement, Shairport Sync provides a system bus D-Bus service enabling a program to get and set Volume, to enable and disable the Loundness Filter and to get and set the Loundness Filter threshold (remember, BTW, the Loudness filter only works with software-based volume control). The implementation is likely to change greatly or be removed at any time. Tested on Ubuntu 16.04 and on Raspbian Stretch. +Two extra configuration options are provided: `--with-dbus` and `--with-dbus-test-client`. (BTW, the test client is never installed, merely compiled.) + +Version 3.1.2 +==== + +Shairport Sync is more stable playing audio from YouTube and SoundCloud on the Mac. + +**Pesky Changes You Should Not Ignore** +* When you update from a previous version of Shairport Sync, your output device may have been left in a muted state. You should use a command line tool like `alsamixer` or `amixer` to unmute the output device before further use. + +**Change of Default** +* The default value for the `alsa` setting `mute_using_playback_switch` has been changed to `"no"` for compatibility with other audio players on the same machine. The reason is that when this setting is set to `"yes"`, the output device will be muted when Shairport Sync releases it. Unfortunately, other audio players using the output device expect it to be unmuted, causing problems. Thanks to [Tim Curtis](https://github.com/moodeaudio) at [Moode Audio](http://moodeaudio.org) and [Peter Pablo](https://github.com/PeterPablo) for clarifying the issue. + +**Bug Fixes** +* Fixed bugs that made Shairport Sync drop out or become unavailable when playing YouTube videos, SoundCloud streams etc. from the Mac. Background: there has been a persistent problem with Shairport Sync becoming unavailable after playing, say, a YouTube clip in a browser on the Mac. Shairport Sync 3.1.2 incorporates a change to how certain AirPlay messages are handled. Introduced in nascent form in 3.1.1, further follow-on changes have improved the handling of player lock and have simplified and improved the handling of unexpected loss of connection. Shairport Sync also now works properly with SoundCloud clips played in a browser on the Mac. +* Using [infer](https://github.com/facebook/infer/blob/master/README.md), a number of silent issues have been detected, such as not checking some calls to `malloc` to ensure the response is not NULL. Most of these have been addressed by additional checks. + +Version 3.1.1 +==== + +**Bug Fixes** +* A bug in the `sndio` backend has been fixed that caused problems on some versions of Linux. +* A change has been made to how Shairport Sync responds to a `TEARDOWN` request, which should make it respond better to sequences of rapid termination and restarting of play sessions. This can happen, for example, playing YouTube videos in Safari or Chrome on a Mac. +* Choosing `soxr` interpolation in the configuration file will now cause Shairport Sync to terminate with a message if Shairport Sync has not been compiled with SoX support. +* Other small changes. + +Version 3.1 +==== +Version 3.1 brings two new backends, optional loudness and convolution filters, improvements in non-synchronised backends, enhancements, stability improvements and bug fixes. + +**New Features** +* A `sndio` backend gives Shairport Sync native fully synchronised output on OpenBSD and FreeBSD, thanks to the work of [Tobias Kortkamp (t6)](https://github.com/t6). +* A `pa` backend now allows Shairport Sync to provide synchronised output on PulseAudio-equipped systems -- many desktop Linuxes use PulseAudio as their sound manager. +* Optional loudness and convolution filters can be incorporated in the audio processing chain, thanks to the fantastic work of [yannpom](https://github.com/yannpom). +* A volume-change program hook `run_this_when_volume_is_set` has been added to the `general` settings stanza to execute an application whenever the volume is changed. + +**Pesky Changes You Should Know About** +* The `audio_backend_buffer_desired_length_in_seconds` and `audio_backend_latency_offset_in_seconds` settings have been moved from individual backend stanzas to the `general` stanza. They now have an effect on every type of backend. +* If you are using a System V (aka `systemv`) installation, please note that the default location for PID file has moved -- it is now stored at `/var/run/shairport-sync/shairport-sync.pid`. This change is needed to improve security a little and to improve compatibility across platforms. If you're not doing anything strange, this should make no difference. + +**Enhancements** +* Resynchronisation, which happens when the synchronisation is incorrect by more than 50 ms by default, should be a lot less intrusive when it occurs – it should now either insert silence or skip frames, as appropriate. +* The Linux installer has been improved and simplified and a FreeBSD installer introduced. +* A new setting, `audio_backend_silent_lead_in_time`, allows you to set the duration of the period of silence played (the "silent lead-in") before a play session starts. +* A new command-line option, `--logOutputLevel`, allows you to output the volume levels to the log whenever they are changed. This may be useful during setup. +* Improvements have been made to the handling of large items of metadata over UDP. +* A new command line option, `-j`, demonizes Shairport Sync without creating a PID file. +* A new `alsa`-only setting, `mute_using_playback_switch`, is available for advanced use. +* Other minor enhancements. + +**Bug Fixes** +* Stability improvements. More care has been taken (!) to make code thread-safe, resulting in improved stability. +* Conversion from stereo to mono has been fixed to avoid clipping while preserving full resolution. Thanks to [Robert Jones (RobDeBagel)](https://github.com/RobDeBagel) for bringing this to notice. +* Short intrusions of audio at the start of a new session from the end of the previous session have been eliminated. +* Many (many!) miscellaneous bugs fixed. + +Version 3.0.2 +==== +**Bug Fixes** +* Fixed bugs in the `ao`, `pulseaudio` and `sndio` back ends. Basically they were expecting default sample rate and depth information, and were terminating when they saw explicit rate and depth data. + +Version 3.0.1 +==== +This update fixes one alarming and potentially very noisy bug and restores the identification of Shairport Sync as "ShairportSync" so that TuneBlade recognises it as an open source application. + +**Bug Fixes** +* Fixed a bug that was causing Shairport Sync to possibly make a very loud and alarming noise whenever an audio frame was missing. +* In 2.8.6, a change was made to the way Shairport Sync identified itself, so that it could be recognised by TuneBlade as an open source application and treated preferentially. That change was inadventently lost in the transition from 2.8.6 to 3.0. Now it's restored. + +Version 3.0 +==== + +Big Update +---- +Version 3 brings in support for 24-bit and 32-bit (and 8 bit!) DACs and for DACs running at multiples of 44,100 samples per second. + +The most obvious audible change is if you are using software volume control and can take advantage of 32- or 24-bit DACs. Dithering can now occur on a 32-bit or 24-bit sample rather than on a 16-bit sample, making the noise floor very much lower. This is the case, for example, with a Pimoroni PHAT DAC. + +Here is the list of new features: + +**New Features** +* 8-bit, 16-bit, 24-bit, 24-bit three-byte (S24_3LE and S24_3BE) and 32-bit output to ALSA devices. +* 44,100, 88,200, 176,400 and 352,800 sample per second output. This is done using simple upsampling. It's only worth doing if 44,100 samples per second output is not available. +* Internal processing including software volume control and interpolation is done after sample size and rate conversion. +* Apple ALAC decoder support. This needs the `libalac` library, available at [ALAC](https://github.com/mikebrady/alac), to be installed. Add the flag `--with-apple-alac` to the `./configure` arguments. Then you can choose the Apple ALAC decoder in the configuration file. +* Support for `mbed TLS` has been added and the use of `PolarSSL` is deprecated, as `mbed TLS` is a development of `PolarSSL` and `PolarSSL` itself is not being developed further. +* Choose Network Interface. Add a new setting, for advanced users only, in the `general` section. Use the `interface` setting to allow you to specify the interface on which to provide the AirPlay service. Omit the setting to get the default, which is to choose the interfaces automatically. +* Set Max Volume. Add a new setting, for advanced users only, in the `general` section. Use the `volume_max_db` setting to allow you to specify the maximum level to set on the hardware mixer (if chosen) or the built-in software mixer otherwise. The software mixer's range is 0.0 dB to -96.1 dB. The setting must be a number with a decimal point, e.g. 21.3. +* An experimental new back end for `libsoundio`, a C library for cross-platform real-time audio input and output. Many thanks to [Serg Podtynnyi](https://github.com/shtirlic). Please see https://github.com/mikebrady/shairport-sync/pull/433 for more details. + + +Pesky Changes You Cannot Ignore +---- +* Processor load is up by about 11%. +* Settings have changed -- basically, any timings that were denominated in frames are now in seconds. Please refer to the shairport-sync.conf.sample file for details. +* Sox-based interpolation at higher sample rates may overload your CPU -- you might have to choose between higher sample rates and sox-based interpolation. + + +Version 3.0rc0 – Release Candidate 0 +---- +Note: all Version 3 changes are summarized above. + +**New Feature** +* An experimental new back end for `libsoundio`, a C library for cross-platform real-time audio input and output. Many thanks to [Serg Podtynnyi](https://github.com/shtirlic). Please see https://github.com/mikebrady/shairport-sync/pull/433 for more details. + +**Other changes** +* Updates to `man` page and [README](https://github.com/mikebrady/shairport-sync/blob/development/README.md). Reports of typos or suggestions for improvement are welcome! + +Version 3.0d24 – Development Version +---- +Note: all Version 3 changes are summarized above. + +**New Feature** +* Set Max Volume. Add a new setting, for advanced users only, in the `general` section. Use the `volume_max_db` setting to allow you to specify the maximum level to set on the hardware mixer (if chosen) or the built-in software mixer otherwise. The software mixer's range is 0.0 dB to -96.1 dB. The setting must be a number with a decimal point, e.g. 21.3. + +Version 3.0d23 – Development Version +---- +Note: all Version 3 changes are summarized above. + +**New Feature** +* Choose Interface. Add a new setting, for advanced users only, in the `general` section. Use the `interface` setting to allow you to specify the interface on which to provide the AirPlay service. Omit the setting to get the default, which is to choose the interfaces automatically. + +Version 3.0d22 – Development Version +---- +Note: all Version 3 changes are summarized above. + +**Bug Fix** +* Fixed a bug which prevented successful building in the OpenWrt build system. The problem was caused by an `#include apple_alac.h` in `player.c` which was actioned even if the apple alac decoder was not selected. This caused the OpenWrt build system to expect the standard C++ library – required by the apple alac code – to be referenced, but it was not specified on the build manifest and therefore stopped the build. The solution was to make the `#include` conditional on selecting the apple alac decoder. + +Version 3.0d21 – Development Version +---- +Note: all Version 3 changes are summarized above. + +**Bug Fix** +* Fixed a bug which turned off resync by default. Duh. + +Version 3.0d20 – Development Version +---- +Note: all Version 3 changes are summarized above. + +**Bug Fix** +* Fix a small and generally silent error in configure.ac so that it only looks for the systemd directory if systemd has been chosen. It caused a warning when cross-compiling. + +Version 3.0d19 – Development Version +---- +Note: all Version 3 changes are summarized above. + +**New Feature** +* Reduces processor load back to V2.X levels by using a precalculated array of pseudorandom numbers to do dithering. Doesn't seem to make any audible difference. + +Version 3.0d18 – Development Version +---- +Note: all Version 3 changes are summarized above. + +**New Features** +* 8-bit, 16-bit, 24-bit, 24-bit three-byte (S24_3LE and S24_3BE) and 32-bit output to ALSA devices. (Other back ends are not updated yet.) +* 44,100, 88,200, 176,400 and 352,800 sample per second output. This is done using simple upsampling. +* Internal processing including software volume control and interpolation is done after sample size and rate conversion. +* Apple ALAC decoder support. This needs the `libalac` library, available at [ALAC](https://github.com/mikebrady/alac). Add the flag `--with-apple-alac` to the `./configure` arguments. Then you can choose the Apple ALAC decoder in the configuration file. +* Support for `mbed TLS` has been added and the use of `PolarSSL` is deprecated, as `mbed TLS` is a development of `PolarSSL` and `PolarSSL` itself is not being developed further. +* Settings that were denominated in frames are now deprecated but still honoured. Deprecation warnings are issued. + +Pesky Changes You Cannot Ignore +==== +* Settings have changed -- basically, any timings that were denominated in frames are now in seconds. Please refer to the shairport-sync.conf.sample file for details. +* Sox-based interpolation at higher sample rates may overload your CPU -- yopu might have to choose between higher sample rates and sox-based interpolation. + +**Bugs** +* Documentation is not updated. + +Version 2.8.6 – Stable Candidate +---- + +**Enhancements** +* This release contains a small change – it identifies itself as a ShairportSync device rather than an AirPort device. This should make it possible for Tuneblade, and possibly other players, to recognise it correctly. + +Version 2.8.5 – Stable Version +---- +This release includes bug fixes and minor enhancements and is recommended for all users. + +Note: if you're upgrading, there is a new `./configure` option: +==== +The build process now uses the directory path `sysconfdir` to determine where to place the configuration file `shairport-sync.conf`. +The default value for `sysconfdir` is `/usr/local/etc` which is used in the BSD family, whereas `/etc` is normally used in Linux. +To retain the present behaviour of Shairport Sync, *you must add an extra parameter to the `./configure... ` command.* The parameter you must add is `--sysconfdir=/etc`. (This has been added to the sample configuration command line in README.md.) + +The enhancements and bug fixes in 2.8.5 were made in versions 2.8.4.1 to 2.8.4.8 inclusive. Please read below for the full list. + +For advice on updating an installation you built yourself, +please visit the [UPDATING](https://github.com/mikebrady/shairport-sync/blob/master/UPDATING.md) page. + +Version 2.8.4.8 – Development Version +---- +**Enhancements** +* Add a new metadata item `clip` (for `CL`ient `IP`). This item is a string comprising the IP number of the "client", and is sent when a play session is starting. The "client" is the sender of the audio stream, e.g. iTunes on a Mac, or the Music player in iOS. +* When synchronisation has been disabled on the ALSA device (you should only do this for testing), Shairport Sync now refrains from asking for buffer length information from the device. + +Version 2.8.4.7 – Development Version +---- + +* This update means the build process now uses the directory path `sysconfdir` to determine where to place the configuration file `shairport-sync.conf`. The default value for `sysconfdir` is `/usr/local/etc` which is used in the BSD family, whereas `/etc` is normally used in Linux. So, to retain the present behaviour of Shairport Sync, you must add an extra parameter to the `./configure... ` command. The parameter you must add is `--sysconfdir=/etc`. (This has been added to the sample configuration command line in README.md.) +* Shairport Sync has been updated to use the value of `sysconfdir` to determine where to look for the configuration file. If `sysconfdir` has been left with its default value of `/usr/local/etc`, then Shairport Sync will look for `/usr/local/etc/shairport-sync.conf`. If, as recommended for Linux, `sysconfdir` has been set to `/etc`, then Shairport Sync will look, as before, for `/etc/shairport-sync.conf`. + +**Enhancement** +* The version string output when you use the command-line option `-V` now includes the value of the `sysconfdir`, e.g. `2.8.4.7-OpenSSL-Avahi-ALSA-soxr-sysconfdir:/etc`. + +Version 2.8.4.6 – Development Version +---- +**Enhancement** +* Add a new `alsa` configuration setting: `use_mmap_if_available` to control the use of mmap. The default is `"yes"` -- see [#351](https://github.com/mikebrady/shairport-sync/issues/351). + +Version 2.8.4.5 – Development Version +---- +**Enhancement** +* Handle varying packet lengths -- this makes it compatible with the HTC Connect, HTCs AirPlay implementation. Thanks to [Jörg Krause](https://github.com/joerg-krause) for his detective work, and see [#338](https://github.com/mikebrady/shairport-sync/issues/338). + +Version 2.8.4.4 – Development Version +---- +**Enhancement** +* Use alsa direct access (mmap) feature to improve performance if mmap is supported. Thanks to [Yihui Xiong](https://github.com/xiongyihui). + +Version 2.8.4.3 – Development Version +---- +**Bug Fix** + +* Set the RTSP socket to close on `exec()` of child processes; otherwise, background `run_this_before_play_begins` or `run_this_after_play_ends` commands that are sleeping prevent the daemon from being restarted because the listening RTSP port is still in use. Fixes [#329](https://github.com/mikebrady/shairport-sync/issues/329). + +Version 2.8.4.2 – Development Version +---- +**Bug Fixes** + +* Fixed an issue where you could not compile the audio_pipe back end without enabling metadata support (thanks to [busa-projects](https://github.com/busa-projects) for reporting the issue). +* Fixed a few small issues causing compiler warnings in `mdns_dns_sd.c`. + + +**Other** +* Removed the INSTALL file – it's generated automatically by `autoreconf -fi` anyway – added it to the files to be ignored in `.gitignore` and added a simple `INSTALL.md` file. + +Version 2.8.4.1 – Development Version +---- +**Bug Fixes** + +* Fixed two issues when including support for `pulseaudio`. +* Corrected two small errors in sample parameters for the UDP metadata stream settings, thanks to [rkam](https://github.com/rkam). + +Version 2.8.4 – Stable Version +---- +This release includes important bug fixes and minor enhancements and is recommended for all users. No settings need to be changed. For advice on updating an installation you built yourself, please visit the [UPDATING](https://github.com/mikebrady/shairport-sync/blob/master/UPDATING.md) page. + +The following is a summary of the bug fixes and enhancements since version 2.8.3. + +**Bug Fixes** + +* Checks have been added for empty or NULL audio buffers that were causing assertion violations and subsequent abnormal program termination. + +* An IPv6 bug has been fixed — a bug in the networking software would not allow an IPv6 link-local connection to be made from a client if Shairport Sync was running on a device with more than one network interface. The solution was to take account of the `config_id` information. + +* Some problems have been fixed with the non-blocking write function used to write metadata. + +* A bug in the volume control transfer function has been fixed, thanks to [Jörg Krause](https://github.com/joerg-krause). + +**Enhancements** + +* Shairport Sync now works with [AllConnect/Streambels](http://allconnectapp.com) on Android with password protection. (As with all Android clients, you should set the `drift` to something large, like 500 or 1,000, as the timekeeping of these clients isn't as accurate as that of iTunes, etc.) + +* The networking subsystem has been modified to always use the same IP number during a session. Background: the computer Shairport Sync is running on can have many IP numbers active at the same time – various IPv6 numbers and also various IPv4 numbers. During a play session, when Shairport Sync has to create connections back to the source, it would use an automatically-assigned IP number for itself, but that number might not be same as the the number used earlier in the session. From now on, it will always use the same IP number it used when the connection was first established. Thanks to [ejurgensen](https://github.com/ejurgensen) for help with this. + +* Experimental support has been added for a softvol plugin, thanks to the work of [Jörg Krause](https://github.com/joerg-krause) -- see [#293](https://github.com/mikebrady/shairport-sync/pull/293). + +* A `playback_mode` setting has been added to allow the selection of `stereo` (default) or `mono` playback -- thanks to [faceless2](https://github.com/faceless2). + +* The new default service name is now the device's `hostname`, with its first character capitalised (ASCII only). + +* Substitutions can now be made in the service name. The following substitutions can be used in the service name: `%h` for the `hostname`, `%H` for the `hostname` with the first letter capitalised, `%v` for the version number and `%V` for the full version string. Maximum length is 50 characters. + +* An existing `shairport-sync.service` file will not be overwritten by `sudo make install`. + +* The text strings advertising the capabilities of Shairport Sync over Bonjour/Zeroconf/Avahi have been changed and now more closely match those of an AirPort Express Base Station (First Generation). + +* It is now possible to set the amount of time to wait for the metadata pipe to become ready for writing. The setting is called `pipe_timeout` in the `metadata` section. Default is 5,000 milliseconds. + +* Metadata can now be provided via UDP -- thanks to [faceless2](https://github.com/faceless2). + +* Statistics output is more machine readable -- thanks to [Jörg Krause](https://github.com/joerg-krause) +* The `shairport-sync.spec` file has been updated for compatibility with building Debian packages using `checkinstall` -- thanks to [vru1](https://github.com/vru1). + +Version 2.8.3.11 – Development Version +---- +**Bug Fix** + +Fixed some problems with the non-blocking write function used to write to the metadata pipe. + +**Enhancement** + +It is now possible to set the amount of time to wait for the metadata pipe to become ready for writing. The setting is called `pipe_timeout` in the `metadata` section. Default is 5,000 milliseconds. + +Version 2.8.3.10 – Development Version +---- +**Bug Fix** + +* Restored metadata feed lost in 2.8.3.7. + +Version 2.8.3.9 – Development Version +---- +**Enhancements** + +* Substitutions can now be made in the service name, i.e. the name that appears in iTunes, etc. The following substitutions can be used in the service name you specify: `%h` for the hostname, `%H` for the hostname with the first letter capitalised, `%v` for the version number and `%V` for the full version string. Maximum length is 50 characters. + +* The new default service name is simply the hostname, with its first character capitalised. + +* An existing `shairport-sync.service` file will not be overwritten by `sudo make install`. + +Version 2.8.3.7 – Development Version +---- +**Enhancements** + +* Shairport Sync now works with AllConnect/Streambels on Android with password protection. (As with all Android clients, you should set the `drift` to something large, like 500 or 1,000, as the timekeeping of these clients isn't as accurate as that of iTunes, etc.) + +* The text strings advertising the capabilities of Shairport Sync over Bonjour/Zeroconf/Avahi have been changed and now more closely match those of an AirPort Express Base Station (First Generation). + +Version 2.8.3.6 – Development Version +---- +**Bug fix** + +An IPv6 link-local connection issue was fixed. A bug in the networking software would not allow an IPv6 link-local connection to be made from a client if Shairport Sync was running on a device with more than one network interface. The solution was to take account of the `config_id` information. + +Version 2.8.3.5 – Development Version +---- +**Enhancement** + +Experimental support for a softvol plugin, thanks to the work of [Jörg Krause](https://github.com/joerg-krause) -- see [#293](https://github.com/mikebrady/shairport-sync/pull/293). + +**Bug fix** + +Add checks for empty or NULL audio buffers that seem to be causing assertion violations and subsequent abnormal program termination. + +Version 2.8.3.4 – Development Version +---- + +**Bug Fix** + +The networking subsystem has been modified to always use the same IP number during a session. Background: the computer Shairport Sync is running on can have many IP numbers active at the same time – various IPv6 numbers and also various IPv4 numbers. During a play session, when Shairport Sync has to create connections back to the source, it would use an automatically-assigned IP number for itself, but that number might not be same as the the number used earlier in the session. From now on, it will always use the same IP number it used when the connection was first established. Thanks to [ejurgensen](https://github.com/ejurgensen) for help with this. + + +Changed the `mono` setting for a `playback_mode` setting with two possible values: `stereo` (default) and `mono`. + +Version 2.8.3.3 – Deleted +---- + +Version 2.8.3.2 – Deleted +---- + +Version 2.8.3.1 – Development Version +---- +Added a new `mono` setting -- thanks to [faceless2](https://github.com/faceless2). Documentation to follow. + +Version 2.8.3 – Stable Version +---- +A bug in 2.8.2 caused Avahi to fail at startup under some circumstances with older installations. The problem was that sometimes the `regtype` setting would not be initialised properly. + +Version 2.8.2 – Stable Version +---- +Version 2.8.2 is derived from development version 2.9.5.7 and has stability improvements, bug fixes and a few special-purpose enhancements. + +For full details, please refer to the release notes here, back as far as 2.8.1. + +Version 2.9.5.7 – Development Version +---- +Version 2.9.5.7 contains general bug fixes and enhancements for some special situations. + +**Bug Fixes** + +* Getting delay and latency information from the `alsa` subsystem has been improved -- bugs fixed, error codes handled better, arithmetic handling (hopefully) better. +* If latency information is temporarily unavailable from the `alsa` subsystem, skip trying to synchronise until the next time. +* Some condition variables and a mutex were uninitialised, yikes! Fixed. +* A bug that set the output volume to maximum at the same time as muting the output has been fixed. AFAIK, this was inaudible, but it was scary looking. +* Recover from name collisions in Avahi. +* Detect and handle empty buffers better. + +**Enhancements** + +* Turn off synchronisation. This is an advanced feature and generally leads to buffer underrun or overrun. +* Set `alsa` buffer size and `alsa` period size. There are advanced features, mainly for debugging. They may be removed. +* Change the Zeroconf/Bonjour `regtype` to enable Shairport Sync to continue to run but to be invisible to AirPlay clients. Special purpose usage only. +* Output total number of packets and the play time of a session when statistics are enabled. + +Version 2.9.4 – Development Version +---- +Version 2.9.4 corrects some bugs in how Avahi error conditions are handled. + +**Bug Fix** +* During operation, if the network disappeared, Avahi would occasionally report an error. This would cause Shairport Sync to attempt to terminate gracefully (which is the wrong thing to do in the circumstances). However, the termination attempt was actually causing an assertion violation crash. These errors are now simply logged. + +Version 2.9.3 – Development Version +---- +Version 2.9.3 is 2.8.1 with documentation and version changes to indicate that it's in the development branch. + +Version 2.8.1 – Stable Version +---- +Version 2.8.1 is derived from development version 2.9.2 and has stability improvements and important bug fixes. + +For full details, please refer to the release notes here, back as far as 2.9.1. + +Version 2.9.2 – Development Version +---- +Version 2.9.2 focuses on further bug fixes and stability improvements. +* Enhanced stability: an important bug has been fixed in the handling of missing audio frames – i.e. what happens when a frame of audio is truly missing, after all attempts to fetch it have been unsuccessful. The bug would cause Shairport Sync to do an unnecessary resynchronisation, or, if resync was turned off, to jump out of sync. This is a long-standing bug – thanks to [Jörg Krause](https://github.com/joerg-krause) for identifying it. +* An extra diagnostic has been added which gives the mean, standard deviation and maximum values for inter-packet reception time on the audio port. It may be useful for exploring line quality. + +Version 2.9.1 – Development Version +---- +Version 2.9.1 focuses on bug fixes and stability improvements. +* Stability improvements are concentrated on what happens when a play sessions ends and is followed immediately by a new session. This happens in iOS 9.2 when you click to the next track or to the previous track. It also happens playing YouTube videos when a Mac's System Audio is routed through AirPlay. Thanks to [Tim Curtis](https://github.com/moodeaudio) for help with these issues. +* A workaround for an apparent flushing issue in TuneBlade has been included. Thanks to [gibman](https://github.com/gibman) for reporting this issue. +* A number of bug fixes have been made to `configure.ac` – thanks to [Jörg Krause](https://github.com/joerg-krause). + +Version 2.8 – Stable Version +---- +Version 2.8 is derived from version 2.7.10 with slight documentation updates. Here is a summary of changes between the last stable version – 2.6 – and this version. For full details, refer to the release notes here, back as far as 2.7. + +**New Feature** +* For hardware mixers with a restricted range (including many cheaper USB DACS), the general `volume_range_db` can be used to specify a wider range than the hardware provides – the extra range is provided by software. + +**Enhancements** +* The `man` manual and the html version of it are automagically rebuilt if `xml2man` and friends are available. +* Volume-setting metadata is now sent even when the volume level is to be ignored by Shairport Sync itself. +* Shairport Sync waits a little longer before asking for missing packets to be resent. Sometimes packets are just arriving slightly out of order and don't need to be asked for again. +* The build scripts have been modified to be a little more compatible with standard practice. +* A Continuous Integration (CI) system – Travis CI – is now used to do some limited build checking (thanks guys!). +* Support added for compiling on Cygwin. +* Added `rtptime` tags to metadata and picture metadata. +* Replaced and improved the dither algorithm used with the software volume control. The new dither code gives a two bit peak-to-peak dither based on a Triangular Probability Distribution Function (TPDF). +* Disabled picture sending if pictures haven’t been asked for. + +**Bug fixes** +* Fixed a bug that prevented Shairport Sync from correctly setting the hardware mixer volume if it had been altered externally. Thanks to [Tim Curtis](https://github.com/moodeaudio) for help with these issues. +* Modified the shutdown behaviour so that a shutdown followed immediately by a play request is handled better. This was causing iOS 9.2 sometimes to drop the Airplay link between tunes. +* Fixed a data-alignment bug that would cause a crash in certain circumstances on ARM processors with metadata enabled. +* Corrected the names for a few settings tags. +* Fixed some typos and misspellings. +* Miscellaneous small bug fixes. + +Version 2.7.10 -- Development Version +---- +**New Feature** +* If the `ignore_volume_control` setting was `yes`, Shairport Sync really did ignore volume control settings and did not send any volume metadata (i.e. `pvol` coded metadata). Now, while continuing to ignore volume control settings, it sends a `pvol` token where the first number is the AirPlay volume, as before, but the remaining three parameters are set to zero. + +Version 2.7.9 -- Development Version +---- +**Bug Fix** +* Oops – brown-bag update. Fixed a crashing bug introduced in the last release, caused by not checking for a hardware mixer before trying to access it, duh. + +Version 2.7.8 -- Development Version +---- +**Bug Fix** +* Fixed an issue whereby Shairport Sync did not reset the hardware mixer volume level before resuming playing. The issue was caused by not releasing and later reaquiring the mixer when pausing and resuming. Thanks to [Tim Curtis](https://github.com/moodeaudio) for reporting the issue. + +Version 2.7.7 -- Development Version +---- +**Enhancements** +* Add note about the Arch Linux Community repository package `shairport-sync`. Thanks to [Anatol Pomozov](https://github.com/anatol). +* Shairport Sync doesn't ask for packets to be resent quite so quickly -- it waits about half a second now before asking for missing packets to be resent. + +**Bug Fixes** +* Improved Shairport Sync's behaviour when it's asked to stop a play session and immediately start another. The signalling system used to stop threads was sometimes stopping threads belonging to the new session. This affected iOS 9.2 users going to the next track -- sometimes the player would become unavailable for an instant and disconnect the session. Th problem still happens occasionally. +* Removed code favouring the use of "public" IPv6 addresses as source addresses when connecting to a distant IPv6 port – Neither OpenWrt nor FreeBSD can use it at present. Also, it's not clear if any problems are being caused by not favouring public IPv6 addresses. + +Version 2.7.6 -- Development Version +---- +**Bug Fixes** +* Look for the correct tag name for desired `ao` buffer length: `audio_backend_buffer_desired_length` rather than `audio_backend_buffer_desired_length_software`. +* Fix a few FreeBSD compilation bugs. +* Fix a few documentation issues and typos. Thanks to [Chris Boot](https://github.com/bootc). + +**Enhancements** +* Add note about installing to Mac OS X. Thanks to [Serg Podtynnyi](https://github.com/shtirlic). +* Add automatic rebuild of manpage and html documentation when `xmltoman` and friends are available. Thanks to [Chris Boot](https://github.com/bootc). +* Favour the use of "public" IPv6 addresses as source addresses when connecting to a distant IPv6 port. + +Version 2.7.5 -- Development Version +---- +**New Features** +* Ubuntu PPA files now available at https://launchpad.net/~dantheperson. + +**Enhancements** +* Broaden the use of the value `$PREFIX` instead of the path `/usr/local/bin` during configuration. Thanks to [dantheperson](https://github.com/dantheperson). + +Version 2.7.4 -- Development Version +---- +**Enhancements** +* Use the correct method for finding the `systemd` unit path, as recommended by Debian maintainers and +http://www.freedesktop.org/software/systemd/man/daemon.html#Installing%20Systemd%20Service%20Files. Thanks to [dantheperson](https://github.com/dantheperson). +* Rather than hardwire the path `/usr/local/bin` as the path to the shairport-sync executable, the value of `$PREFIX` is now used during configuration. Thanks to [Nick Steel](https://github.com/kingosticks). +* Add some extra diagnostic messages if the hardware buffer in the DAC is smaller than desired. +* If metadata has been enabled, but if picture sending has not been requested and the source sends pictures anyway, omit them from the metadata feed. Thanks to [Jörg Krause](https://github.com/joerg-krause). + +**Bug Fixes** +* Fixed a data alignment issue in the handling of metadata on some processors. Thanks to [Jörg Krause](https://github.com/joerg-krause). +* Removed an `assert` which would terminate the program if a malformed packet of data was received. +* Look for the correct tag name for desired alsa buffer length: `audio_backend_buffer_desired_length` rather than `audio_backend_buffer_desired_length_software`. + +Version 2.7.3 -- Development Version +---- +**Bug Fix** +* The dither code was broken in Shairport Sync and also less than ideal anyway. Fixed and improved. Dither is added whenever you use the software volume control at less than full volume. See http://www.ece.rochester.edu/courses/ECE472/resources/Papers/Lipshitz_1992.pdf for a very influential paper by Lipshitz, Wannamaker and Vanderkooy, 1992. The dither code in Shairport Sync was inherited from Shairport and does not conform to the recommendations in the paper -- specifically the implementation would give one bit of dither where the paper recommends two bits peak-to-peak. The other thing is that the inherited dither code was actually broken in Shairport Sync. So, the new dither code gives a two bit peak-to-peak dither based on a Triangular Probability Distribution Function (TPDF). It sounds like a very low-level white noise, unmodulated by the audio material. It would be nice if it was even lower, but it's better than listening to the artifacts present when dithering is disabled. + +Version 2.7.2 -- Development Version +---- +**Bug Fix** +* Fix a bug that suppressed output of the `rtptime` associated with metadata and with picture information coming from the audio source and passed on via the metadata pipe. + +**Other Changes** +* Added some more information to the log whenever problems are detected with the proposed alsa device. + +Version 2.7.1 -- Development Version +---- +**Bug Fix** +* The new volume-extension code was not correctly setting the volume after a pause / resume. Fixed. + +Version 2.7 -- Development Version +---- +**New Features** +* Extend the volume range for some DACs. Background: some of the cheaper DACS have a very small volume range (that is, the ratio of the highest to the lowest volume, expressed in decibels, is very small). In some really cheap DACs it's only around 30 dB. That means that the difference between the lowest and highest volume settings isn't large enough. With the new feature, if you set the `general` `volume_range_db` to more than the hardware mixer's range, Shairport Sync will combine the hardware mixer's range with a software attenuator to give the desired range. For example, suppose you want a volume range of 70 dB and the hardware mixer offers only 30 dB, then Shairport Sync will make up the other 40 dB with a software attenuator. One drawback is that, when the volume is being changed, there may be a slight delay (0.15 seconds by default) as the audio, whose volume may have been adjusted in software, propagates through the system. Another slight possible drawback is a slightly heavier load on the processor. +* Check for underflow a little better when buffer aliasing occurs on very bad connections... +* Add extra debug messages to the alsa back end to diagnose strange DACs. +* Add configuration file for the `libao` back end -- to change the buffer size and the latency offset, same as for stdout. +* Add `shairport-sync.exe` to `.gitignore`. +* Add a check to support compilation on a CYGWIN platform. +* Add `rtptime` tags to metadata and picture information and add two new metadata items to precede and follow the transmission of a picture. Background: it seems that metadata and picture information for the same item, e.g. a track, are normally tagged with a timestamp called the `rtptime`; if they refer to the same item, they will have the same `rtptime` tags. The update here is to add the `rtptime` value, if available, as data to the `mdst` and `mden` metadata items, which are sent before ("MetaData STart") and after ("MetaData ENd") a metadata sequence. +In addition, similar tags -- `pcst` ("PiCture STart") and `pcen` ("PiCture ENd") are now sent before and after a picture with the `rtptime` value, if available, sent as data. +By the way, the progress metadata (`prgr` for "PRoGRess"), which is sent just when a track starts, contains the same `rtptime` as its middle element. + + +Version 2.6 -- Stable Version +---- +This is basically version 2.4.2 with two small fixes. It's been bumped to 2.6 because (1) the new features added between 2.4.1 and 2.4.2 deserve more than just a bug-fix increment and (2) the development versions (2.5.x) should have lower numbers than the release versions, so that releases are always seen as upgrades. For example: 2.5.0.9 --> 2.6 looks like an upgrade, whereas 2.5.0.9 --> 2.4.2 looks like a downgrade. + +**Fixes** +* For `systemd` users, the `shairport-sync.service` file is updated to point to the correct location of the shairport-sync application. +* For Fedora users, the `shairport-sync.spec` file is updated to refer to 2.6. + + +Version 2.4.2 +---- +This release has important enhancements, bug fixes and documentation updates. It also appears to bring compatibility with Synology NAS devices. + + +**New Features** +* Source-specified Latencies. Shairport Sync now uses the latencies specified by the audio source. Background: the AirPlay protocol used by Shairport Sync allows the audio source to specify the exact delay or latency that should be applied to the audio stream. Until now, Shairport Sync ignored this information and used fixed preset latencies that were selected on the basis of the "User-Agent" setting. Using source-specified latencies means that Shairport Sync is able adapt automatically to different sources. +Using source-specified latencies is now automatic unless non-standard static latencies have been specified in the configuration file or command line. Using non-standard latencies is usually done to compensate for delays in the back end of the system. For example, if the audio amplifier being driven by Shairport Sync has an inherent delay of its own -- as happens with many home theatre and surround sound systems -- then some users have reduced the latencies used by Shairport Sync to compensate. This usage is discouraged -- the `audio_backend_latency_offset` in the appropriate backend stanza (e.g. in the "alsa" stanza) should be used for this. Static latency settings are now deprecated, and will be removed in a future version of Shairport Sync. +* Set Volume Range. This is a new setting that allows you to use just a portion of the full range of attenuation offered by a mixer. For example, if a mixer has a minimum volume of -80 dB and a maximum of +20 dB, you might wish to use only 60 dB of the 100 dB available. This might be because the sound becomes inaudible at the lowest setting and unbearably loud at the highest setting. It is for this reason that many domestic HiFi systems have a volume control range of only 60 to 80 dB. + Another possible reason to use this setting might be because the range specified by the mixer does not match the actual capabilities of the device. For example, the Raspberry Pi's DAC that feeds the built-in audio jack claims a range of 106 dB but has a useful range of only about 35dB. The new `volume_range_db` setting in the `general` stanza allows you to specify the maximum range from highest to lowest. The range suggested for the Raspberry Pi's built-in audio DAC, which feeds the headphone jack, is 35. Using it in this case gives the volume control a much more useful range of settings. + +**Bug fixes** +* Sometimes, especially when using Shairport Sync as a system output, it would not play the audio stream. This was caused by an improperly initialised variable. Fixed. Synology NAS devices now seem to be working with Shairport Sync. +* Fix in the `shairport.c`: the USE_CUSTOM_LOCAL_STATE_DIR macro was still being used when it should have been USE_CUSTOM_PID_DIR. +* Fix a crashing bug -- if metadata was enabled but a pipename was not supplied, boom. + +**Other Changes** +* Initial timing accuracy improved. The estimate of when to play the starting frame of the audio sequence has improved significantly. This leads to fewer corrections being needed at the start. +* Volume ratios expressed in decibels are now consistently denominated in voltage decibels rather than power decibels. The rationale is that the levels refer to voltage levels, and power is proportional to the square of voltage. +Thus a ratio of levels of 65535 to 1 is 96.3 dB rather than the 48.15 dB used before. +* The latency figure returned to the source as part of the response to an rtsp request packet is 11,025, which may (?) be meant to indicate the minimum latency the device is capable of. +* An experimental handler for a GET_PARAMETER rtsp request has been added. It does nothing except log the occurrence. +* The RTSP request dispatcher now logs an event whenever an unrecognised rtsp has been made. + + +Version 2.4.1 +---- +This release has three small bug fixes and some small documentation updates. + +**Bug Fixes** + +Changes from the previous stable version -- 2.4 -- are summarised here: + * The USE_CUSTOM_LOCAL_STATE_DIR macro was still being used when it should have been USE_CUSTOM_PID_DIR. This could affect users using a custom location for the PID directory. + * A compiler error has been fixed that occurred if metadata was enabled and tinysvcmdns was included. + * A crash has been fixed that occurred if metadata was enabled and a metadata pipe name was not specified. +(Thanks to the contributors who reported bugs.) + +**Small Changes** + * If a mixer being used to control volume does not have a control denominated in dB, a warning is logged and the mixer is not used. + * Slight revisions have been made to the configuration file `configure.ac` to make compilation on FreeBSD a little easier. + +Version 2.4 +---- +**Stable release** + +This stable release is the culmination of the 2.3.X sequence of development releases. + +**Change Summary** + +Changes from the previous stable version -- 2.2.5 -- are summarised here: + * Settings are now read from a configuration file. Command-line settings are supported but discouraged. + * Metadata is now supported -- it can be delivered to a unix pipe for processing by a helper application. See https://github.com/mikebrady/shairport-sync-metadata-reader for a sample metadata reader. + * Raw PCM audio can be delivered to standard output ("stdout") or to a unix pipe. The internal architecture has changed considerably to support this. + * Support for compilation on OpenWrt back to Attitude Adjustment. + * Can play unencrypted audio streams -- complatible with, e.g. Whaale. + * Uses the libconfig library. + * Runs on a wider range of platforms, including Arch Linux and Fedora. + * Bug fixes. + +Please note that building instructions have changed slightly from the previous version. +Also, the `-t hardware/software` option has been deprecated in the alsa back end. + +Version 2.3.13 +---- +**Note** +* We're getting ready to release the development branch as the new, stable, master branch at 2.4. If you're packaging Shairport Sync, you might prefer to wait a short while as we add a little polish before the release. + +**Changes** +* Harmonise version numbers on the release and on the `shairport.spec` file used in Fedora. + +Version 2.3.12 +---- +**Note** +* We're getting ready to release the development branch as the new, stable, master branch at 2.4. If you're packaging Shairport Sync, you might prefer to wait a short while as we add a little polish before the release. + +**Changes** +* `update-rc.d` has been removed from the installation script for System V because it causes problems for package makers. It's now noted in the user installation instructions. +* The `alsa` group `mixer_type` setting is deprecated and you should stop using it. Its functionality has been subsumed into `mixer_name` – when you specify a `mixer_name` it automatically chooses the `hardware` mixer type. + + +**Enhancements** +* Larger range of interpolation. Shairport Sync was previously constrained not to make interpolations ("corrections") of more than about 1 per 1000 frames. This constraint has been relaxed, and it is now able to make corrections of up to 1 in 352 frames. This might result in a faster and undesirably sudden correction early during a play session, so a number of further changes have been made. The full set of these changes is as follows: + * No corrections happen for the first five seconds. + * Corrections of up to about 1 in 1000 for the next 25 seconds. + * Corrections of up to 1 in 352 thereafter. + +**Documentation Update** +* Nearly there with updates concerning the configuration file. + +Version 2.3.11 +---- +Documentation Update +* Beginning to update the `man` document to include information about the configuration file. It's pretty sparse, but it's a start. + +Version 2.3.10 +---- +Bug fix +* The "pipe" backend used output code that would block if the pipe didn't have a reader. This has been replaced by non-blocking code. Here are some implications: + * When the pipe is created, Shairport Sync will not block if a reader isn't present. + * If the pipe doesn't have a reader when Shairport Sync wants to output to it, the output will be discarded. + * If a reader disappears while writing is occurring, the write will time out after five seconds. + * Shairport Sync will only close the pipe on termination. + +Version 2.3.9 +---- +* Bug fix + * Specifying the configuration file using a *relative* file path now works properly. + * The debug verbosity requested with `-v`, `-vv`, etc. is now honoured before the configuration file is read. It is read and honoured from when the command line arguments are scanned the first time to get a possible configuration file path. + +Version 2.3.8 +---- +* Annoying changes you must make + * You probably need to change your `./configure` arguments. The flag `with-initscript` has changed to `with-systemv`. It was previously enabled by default; now you must enable it explicitly. + +* Changes + * Added limited support for installing into `systemd` and Fedora systems. For `systemd` support, use the configuration flag `--with-systemd` in place of `--with-systemv`. The installation does not do everything needed, such as defining special users and groups. + * Renamed `with-initscript` configuration flag to `with-systemv` to describe its role more accurately. + * A System V startup script is no longer installed by default; if you want it, ask for it with the `--with-systemv` configuration flag. + * Added limited support for FreeBSD. You must specify `LDFLAGS='-I/usr/local/lib'` and `CPPFLAGS='-L/usr/local/include'` before running `./configure --with-foo etc.` + * Removed the `-configfile` annotation from the version string because it's no longer optional; it's always there. + * Removed the `dummy`, `pipe` and `stdout` backends from the standard build – they are now optional and are no longer automatically included in the build. + +* Bug fixes + * Allow more stack space to prevent a segfault in certain configurations (thanks to https://github.com/joerg-krause). + * Add missing header files(thanks to https://github.com/joerg-krause). + * Removed some (hopefully) mostly silent bugs from the configure.ac file. + +Version 2.3.7 +---- +* Changes + * Removed the two different buffer lengths for the alsa back end that made a brief appearance in 2.3.5. +* Enhancements + * Command line arguments are now given precedence over config file settings. This conforms to standard unix practice. + * A `–without-pkg-config` configuration argument now allows for build systems, e.g. for older OpenWrt builds, that haven't fully implemented it. There is still some unhappiness in arch linux builds. +* More + * Quite a bit of extra diagnostic code was written to investigate clock drift, DAC timings and so on. It was useful but has been commented out. If might be useful in the future. + +Version 2.3.5 +---- +* Changes + * The metadata item 'sndr' is no longer sent in metadata. It's been replaced by 'snam' and 'snua' -- see below. +* Enhancements + * When a play session is initiated by a source, it attempts to reserve the player by sending an "ANNOUNCE" packet. Typically, a source device name and/or a source "user agent" is sent as part of the packet. The "user agent" is usually the name of the sending application along with some more information. If metadata is enabled, the source name, if provided, is emitted as a metadata item with the type `ssnc` and code `snam` and similarly the user agent, if provided, is sent with the type `ssnc` and code `snua`. + * Two default buffer lengths for ALSA -- default 6615 frames if a software volume control is used, to minimise the response time to pause and volume control changes; default 22050 frames if a hardware volume control is used, to give more resilience to timing problems, sudden processor loading, etc. This is especially useful if you are processing metadata and artwork on the same machine. + * Extra metadata: when a play session starts, the "Active-Remote" and "DACP-ID" fields -- information that can be used to identify the source -- are provided as metadata, with the type `ssnc` and the codes `acre` and `daid` respectively. The IDs are provided as strings. + * Unencrypted audio data. The iOS player "Whaale" attempts to send unencrypted audio, presumably to save processing effort; if unsuccessful, it will send encrypted audio as normal. Shairport Sync now recognises and handles unencrypted audio data. (Apparently it always advertised that it could process unencrypted audio!) + * Handle retransmitted audio in the control channel. When a packet of audio is missed, Shairport Sync will ask for it to be retransmitted. Normally the retransmitted audio comes back the audio channel, but "Whaale" sends it back in the control channel. (I think this is a bug in "Whaale".) Shairport Sync will now correctly handle retransmitted audio packets coming back in the control channel. +* Bugfixes + * Generate properly-formed `..` items of information. + +Version 2.3.4 +---- +* Enhancement + * When a play session starts, Shairport Sync opens three UDP ports to communicate with the source. Until now, those ports could be any high numbered port. Now, they are located within a range of 100 port locations starting at port 6001. The starting port and the port range are settable by two new general settings in `/etc/shairport-sync.conf` -- `udp_port_base` (default 6001) and `udp_port_range` (default 100). To retain the previous behaviour, set the `udp_port_base` to `0`. +* Bugfixes + * Fix an out-of-stack-space error that can occur in certain cases (thanks to https://github.com/joerg-krause). + * Fix a couple of compiler warnings (thanks to https://github.com/joerg-krause). + * Tidy up a couple of debug messages that were emitting misleading information. + +Version 2.3.3.2 +---- +* Bugfix -- fixed an error in the sample configuration file. + +Version 2.3.3.1 +---- +* Enhancement + * Metadata format has changed slightly -- the format of each item is now `........`, where the `..` part is present if the length is non-zero. The change is that everything is now enclosed in an `..` pair. + +Version 2.3.2 and 2.3.3 +---- +These releases were faulty and have been deleted. + +Version 2.3.1 +----- +Some big changes "under the hood" have been made, leading to limited support for unsynchronised output to `stdout` or to a named pipe and continuation of defacto support for unsynchronised PulseAudio. Also, support for a configuration file in preference to command line options, an option to ignore volume control and other improvements are provided. + +In this release, Shairport Sync gains the ability to read settings from `/etc/shairport-sync.conf`. +This gives more flexibility in adding features gives better compatibility across different versions of Linux. +Existing command-line options continue to work, but some will be deprecated and may disappear in a future version of Shairport Sync. New settings will only be available via the configuration file. + +Note that, for the present, settings in the configuration will have priority over command line options for Shairport Sync itself, in contravention of the normal unix convention. Audio back end command line options, i.e. those after the `--`, have priority over configuration file settings for the audio backends. + +In moving to the the use of a configuration file, some "housekeeping" is being done -- some logical corrections and other small changes are being made to option names and modes of operations, so the settings in the configuration file do not exactly match command line options. + +When `make install` is executed, a sample configuration is installed or updated at `/etc/shairport-sync.conf.sample`. The same file is also installed as `/etc/shairport-sync.conf` if that file doesn't already exist. To prevent the configuration files being installed, use the configuration option `--without-configfiles`. + +* Pesky Change You Must Do Something About + +If you are using metadata, please note that the option has changed somewhat. The option `-M` has a new long name equivalent: `--metadata-pipename` and the argument you provide must now be the full name of the metadata pipe, e.g. `-M /tmp/shairport-sync-metadata`. + +* Enhancements + * Shairport Sync now reads settings from the configuration file `/etc/shairport-sync.conf`. This has settings for most command-line options and it's where any new settings will go. A default configuration file will be installed if one doesn't exist, and a sample file configuration file is always installed or updated. Details of settings are provided in the sample file. Shairport Sync relies on the `libconfig` library to read configuration files. For the present, you can disable the new feature (and save the space taken up by `libconfig`) by using the configure option `--without-configfile-support`. + * New command-line option `-c ` or `--configfile=` allows you to specify a configuration file other than `/etc/shairport-sync.conf`. + * Session Timeout and Allow Session Interruption can now be set independently. This is really some "housekeeping" as referred to above -- it's a kind of a bug fix, where the bug in question is an inappropriate connection of the setting of two parameters. To explain: (1) By default, when a source such as iTunes starts playing to the Shairport Sync device, any other source attempting to start a play session receives a "busy" signal. If a source disappears without warning, Shairport Sync will wait for 120 seconds before dropping the session and allowing another source to start a play session. (2) The command-line option `-t` or `--timeout` allows you to set the wait time before dropping the session. If you set this parameter to `0`, Shairport Sync will not send a "busy" signal, thus allowing another source to interrupt an existing one. (3) The problem is that if you set the parameter to `0`, a session will never be dropped if the source disappears without warning. + The (obvious) fix for this is to separate the setting of the two parameters, and this is now done in the configuration file `/etc/shairport-sync.conf` -- please see the settings `allow_session_interruption` and `session_timeout`. The behaviour of the `-t` and `--timeout` command-line options is unchanged but deprecated. + * New Option -- "Ignore Volume Control" ('ignore_volume_control'). If you set this to "yes", the output from Shairport Sync is always set at 100%. This is useful when you want to set the volume locally. Available via the settings file only. + * Statistics option correctly reports when no frames are received in a sampling interval and when output is not being synchronised. + * A new, supported audio back end called `stdout` provides raw 16-bit 44.1kHz stereo PCM output. To activate, set `output_backend = "stdout"` in the general section of the configuration file. Output is provided synchronously with the source feed. No stuffing or stripping is done. If you are feeding it to an output device that runs slower or faster, you'll eventually get buffer overflow or underflow in that device. To include support for this back end, use the configuration option `--with-stdout`. + * Support for the `pipe` back end has been enhanced to provide raw 16-bit 44.1kHz stereo PCM output to a named pipe. To activate, set `output_backend = "pipe"` in the general section of the configuration and give the fully-specified pathname to the pipe in the pipe section of the configuration file -- see `etc/shairport-sync.conf.sample` for an example. No stuffing or stripping is done. If you are feeding it to an output device that runs slower or faster, you'll eventually get buffer overflow or underflow in that device. To include support for this back end, use the configuration option `--with-pipe`. + * Support for the `dummy` audio backend device continues. To activate, set `output_backend = "dummy"` in in the general section of the configuration. To include support for this back end, use the configuration option `--with-dummy`. + * Limited support for the PulseAudio audio backend continues. To activate, set `output_backend = "pulse"` in in the general section of the configuration. You must still enter its settings via the command line, after the `--` as before. Note that no stuffing or stripping is done: if the PulseAudio sink runs slower or faster, you'll eventually get buffer overflow or underflow. + * New backend-specific settings are provided for setting the size of the backend's buffer and for adding or removing a fixed offset to the overall latency. The `audio_backend_buffer_desired_length` default is 6615 frames, or 0.15 seconds. On some slower machines, particularly with metadata processing going on, the DAC buffer can underflow on this setting, so it might be worth making the buffer larger. A problem on software mixers only is that changes to volume control settings have to propagate through the buffer to be heard, so the larger the buffer, the longer the response time. If you're using an alsa back end and are using a hardware mixers, this isn't a problem. The `audio_backend_latency_offset` allows you emit frames to the audio back end some time before or after the synchronised time. This would be useful, for example, if you are outputting to a device that takes 20 ms to process audio; yoou would specify a `audio_backend_latency_offset = -882`, where 882 is the number of frames in 20 ms, to compensate for the device delay. + +Version 2.3 +----- +* Enhancements + * Adding the System V startup script (the "initscript") is now a configuration option. The default is to include it, so if you want to omit the installation of the initscript, add the configuration option `--without-initscript`. + * Metadata support is now a compile-time option: `--with-metadata`. + * A metadata feed has been added. Use the option `-M `, e.g. `-M /tmp`. Shairport Sync will provide metadata in a pipe called `/shairport-sync-metadata`. (This is changed in 2.3.1.) There's a sample metadata reader at https://github.com/mikebrady/shairport-sync-metadata-reader. The format of the metadata is a mixture of XML-style tags, 4-character codes and base64 data. Please look at `rtsp.c` and `player.c` for examples. Please note that the format of the metadata may change. +Beware: there appears to be a serious bug in iTunes before 12.1.2, such that it may stall for a long period when sending large (more than a few hundred kilobytes) coverart images. + +* Bugfix + * Fix a bug when compiling for Arch Linux on Raspberry Pi 2 (thanks to https://github.com/joaodriessen). + * Fix a bug whereby if the ANNOUNCE and/or SETUP method fails, the play_lock mutex is never unlocked, thus blocking other clients from connecting. This can affect all types of users, but particularly Pulseaudio users. (Thanks to https://github.com/jclehner.) + * Modify the init script to start after all services are ready. Add in a commented-out sleep command if users find it necessary (thanks to https://github.com/BNoiZe). + * Two memory leaks fixed (thanks to https://github.com/pdgendt). + * An error handling time specifications for flushes was causing an audible glitch when pausing and resuming some tracks. This has been fixed (thanks to https://github.com/Hamster128). + +Version 2.2.5 +----- +* Bugfixes + * Fix a segfault error that can occur in certain cases (thanks again to https://github.com/joerg-krause). + * Include header files in common.c (thanks again to https://github.com/joerg-krause). + +Version 2.2.4 +----- +* Bugfixes + * Fix an out-of-stack-space error that can occur in certain cases (thanks to https://github.com/joerg-krause). + * Fix a couple of compiler warnings (thanks to https://github.com/joerg-krause). + +Version 2.2.3 +----- +* NOTE: all the metadata stuff has been moved to the "development" branch. This will become the stable branch henceforward, with just bug fixes or minor enhancements. Apologies for the inconvenience. +* Bugfixes + * Fix a bug when compiling for Arch Linux on Raspberry Pi 2 (thanks to https://github.com/joaodriessen). + * Fix a compiler warning (thanks to https://github.com/sdigit). + +Version 2.2.2 +----- +* Enhancement + * An extra latency setting for forked-daapd sources -- 99,400 frames, settable via a new option `--forkedDaapdLatency`. + +Version 2.2.1 +----- +* Bugfixes: + * If certain kinds of malformed RTSP packets were received, Shairport Sync would stop streaming. Now, it generally ignores faulty RTSP packets. + * The `with-pulseaudio` compile option wasn't including a required library. This is fixed. Note that the PulseAudio back end doesn't work properly and is just included in the application because it was there in the original shairport. Play with it for experimentation only. + * Fix typo in init.d script: "Headphones" -> "Headphone". +* Extra documentation + * A brief note on how to compile `libsoxr` from source is included for the Raspberry Pi. + +Version 2.2 +----- +* Enhancements: + * New password option: `--password=SECRET` + * New tolerance option: `--tolerance=FRAMES`. Use this option to specify the largest synchronisation error to allow before making corrections. The default is 88 frames, i.e. 2 milliseconds. The default tolerance is fine for streaming over wired ethernet; however, if some of the stream's path is via WiFi, or if the source is a third-party product, it may lead to much overcorrection -- i.e. the difference between "corrections" and "net correction" in the `--statistics` option. Increasing the tolerance may reduce the amount of overcorrection. + +Version 2.1.15 +----- +* Changes to latency calculations: + * The default latency is now 88,200 frames, exactly 2 seconds. It was 99,400 frames. As before, the `-L` option allows you to set the default latency. + * The `-L` option is no longer deprecated. + * The `-L` option no longer overrides the `-A` or `-i` options. + * The default latency for iTunes is now 99,400 frames for iTunes 10 or later and 88,200 for earlier versions. + * The `-i` or `--iTunesLatency` option only applies to iTunes 10 or later sources. + +Version 2.1.14 +----- +* Documentation update: add information about the `-m` audio backend option. +The `-m` audio backend option allows you to specify the hardware mixer you are using. Not previously documented. +Functionality of shairport-sync is unchanged. + +Version 2.1.13 +----- +* Compilation change: Begin to use PKG_CHECK_MODULES (in configure.ac) to statically link some of the libraries used by shairport-sync. It is intended to make it easier to build in the buildroot system. While sufficient for that purpose, note that PKG_CHECK_MODULES is not used for checking all the libraries yet. +Functionality of shairport-sync is unchanged. + +Version 2.1.12 +----- +* Enhancement: `--statistics` + Statistics are periodically written to the console (or the logfile) if this command-line option is included. They are no longer produced in verbose (`-v`) mode. +* Bugfixes for `tinysvcmdns` + * A bug that prevented the device's IP number(s) and port numbers being advertised when using `tinysvcmdns` has been fixed. (Cause: name needed to have a `.local` suffix.) + * Bugs causing the shairport service to semi-randomly disappear and reappear seem to be fixed. (Possible cause: incorrect timing settings when using `tinysvcmdns`.) + +Version 2.1.11 +----- +* Enhancement + * A man page is now installed -- do `man shairport-sync` or see it here: http://htmlpreview.github.io/?https://github.com/mikebrady/shairport-sync/blob/2.1/man/shairport-sync.html. + +Version 2.1.10 +----- +* Bugfix + * A bug that caused the `-t` timeout value to be incorrectly assigned has been fixed. (Cause: `config.timeout` defined as `int64_t` instead on `int`.) + +Version 2.1.9 +----- +* Bugfixes + * A bug that sometimes caused the initial volume setting to be ignored has been fixed. (Cause: setting volume before opening device.) + * a bug that caused shairport-sync to become unresponsive or unavailable has been fixed. (Cause: draining rather than flushing the alsa device before stopping.) + +Version 2.1.8: +----- +* Enhancements + * (This feature is intended to be useful to integrators.) Shairport Sync now the ability to immediately disconnect and reconnect to the sound output device while continuing to stream audio data from its client. +Send a `SIGUSR2` to the shairport-sync process to disconnect or send it a `SIGHUP` to reconnect. If shairport-sync has been started as a daemon using `shairport-sync -d`, then executing `shairport-sync -D` or `--disconnectFromOutput` will request the daemon to disconnect, and executing `shairport-sync -R` or `--reconnectToOutput` will request it to reconnect. +With this feature, you can allow Shairport Sync always to advertise and provide the streaming service, but still be able to disconnect it locally to enable other audio services to access the output device. + +* Annoying things you should know about if you're updating from a previous version: + * Options `--with-openssl`, `--with-polarssl` have been replaced with a new option `--with-ssl=