The runtime image carries only shairport-sync and its libraries and
expects the node's avahi via the host D-Bus socket; nqptp runs as a
sidecar sharing /dev/shm.
Streams AirPlay audio to OpenHome/Songcast receivers as OHU unicast PCM
(16/24-bit). Sends are paced on the PTP master clock so receivers slave
to the AirPlay group clock through their buffer-fill servo; MediaLatency
carries the phase, matching the wire behaviour of Linn's own sender
(zero flags and timestamps). delay() reports the newest frame's playtime
lead so shairport feeds a receiver latency ahead. Handles Join, Listen,
Leave and Resend with a frame history, and forwards track metadata and
metatext from the metadata hub.
With -r <name>, ohm_upnp controls the receiver over UPnP: discovered by
friendly name via SSDP at time of use, woken, switched to its Songcast
source and pointed at this sender when a session starts; volume follows
the AirPlay slider capped at the device's VolumeLimit; standby follows
some minutes after the session ends.
Enable the AirPlay 2 build to operate an optional classic-AirPlay-only service or to gracefully degrade to classic AirPlay, as follows:
1. Add a new command-line option '-—service-type=<type>' and an equivalent configuration entry 'service_type = "<type>"' in the 'general' section of the configuration file,
where <type> can be "auto", "classic" or "airplay2":
1. "auto" (default) means that the service will be AirPlay 2 if NQPTP is running. If NQPTP is not running, classic AirPlay service will be provided instead, and in that case,
"(Classic)" will be appended to the default AirPlay service name visible to AirPlay clients like Apple Music, for example "RaspberryPi3B (Classic)".
2. "classic" means the service will be classic AirPlay (aka AirPlay 1).
3. "airplay2" means the service will be the modern AirPlay 2. In this case, as distinct from "auto", if NQPTP is not running, Shairport Sync will log an error and terminate.
2. In the systemd service file, NQPTP is now a "Want" rather than a "Require". If it's present, then it will be launched before Shairport Sync. If it's absent, Shairport Sync will launch anyway.
3. Improve the delivery of input format changes and emit 'sdsc' metadata when changes occur.
4. Emit new format information in the log if statistics is enabled.
Docker Changes
1. Support for linux/arm/v6 has been dropped, as Docker is no longer supported.
2. NQPTP is not started in the AirPlay 2 Docker image if '--service-type=classic' or '--service-type=airplay1' is in the command line options at the end of the docker run command.
The purpose is to ensure that ports 319 and 320 are left alone when the AirPlay 2 image is set to provide Classic service only.
Note that setting the configuration file 'service_type' to 'classic' will not prevent NQPTP from starting up -- you must use the command line option.
3. A new "dev" target has been added. It is a large image containing the custom-built FFmpeg library, NQPTP, Avahi and D-Bus along with the Shairport Sync source and
all necessary development tools. When started, Avahi, D-Bus and NQPTP are all installed and running. The bash shell has also been added and is entered.
Stability Improvements
Reorganise session preemption to fully terminate the existing session before starting a new one.
Don't delay closing the event port to wait for it to be closed at the client end.
Add a safe_socket_close() function to ensure sockets are fully closed. Use -1 to designate closed rather than 0, to prevent attempts to reclose sockets, causing mayhem.
Re-order FFmpeg decommissioning during teardown.
ENABLE_AVAHI decides whether dbus and avahi daemons run inside the
container or if the host's instances are reused. When set to 0,
/var/run/dbus and /var/run/avahi-daemon/socket must be bind-mounted
by the user from the host into the container.
- 48,000 frames per second operation,
- 48k lossless stereo, 5.1 and 7.1 surround sound
- Multichannel and multi rate operation on ALSA, PipeWire, PulseAudio, FreeBSD, stdout and unix pipe output backends.
Automatic, flexible and controllable output format (rate, sample format and channel count) selection.
Full FFmpeg integration to support transcoding, resampling, and new audio formats.
Better operation on lower powered devices down to e.g. Raspberry Pi B.
Reduced Docker image sizes with a slimmed-down FFmpeg library.
Enhanced timestamp handling for better synchronization.
Improved the sync error calculation.
A new "vernier" resampling and interpolation method for low-power CPUs.
Bug fixes and minor enhancements.
Note -- there are many breaking changes from previous versions of Shairport Sync!
From mandoc man(1) [-s] section:
1 General commands (tools and utilities).
[...]
7 Miscellaneous information.
From GNU man(1) DESCRIPTION:
1 Executable programs or shell commands
[...]
7 Miscellaneous (including macro packages and conventions), e.g.
man(7), groff(7)
shairport-sync is an executable, shairport-sync(1) ought to be its
documentation, not merely miscellaneous information.
OpenBSD adjusts this in its audio/shairport-sync port/package ever since.