Files
shairport-sync/audio_sndio.c
T
Mike Brady 83c0405d03 Add automatic bit depth and speed selection for alsa devices. Set rate and format to "auto" by default. Always look for the greatest bit depth, but the lowest multiple of 44,100.
Improve support for big-endian CPUs by adding support for explicit -endian formats, i.e. S16_LE, S16_BE, S24_LE, S24_BE, S32_LE, S32_BE.

For the "disable_standby_mode" setting, change "while_active" to "auto".
2019-05-07 10:19:04 +01:00

281 lines
9.2 KiB
C

/*
* sndio output driver. This file is part of Shairport Sync.
* Copyright (c) 2013 Dimitri Sokolyuk <demon@dim13.org>
* Copyright (c) 2017 Tobias Kortkamp <t@tobik.me>
*
* Modifications for audio synchronisation
* and related work, copyright (c) Mike Brady 2014 -- 2017
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "audio.h"
#include "common.h"
#include <pthread.h>
#include <sndio.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
static void help(void);
static int init(int, char **);
static void onmove_cb(void *, int);
static void deinit(void);
static void start(int, int);
static int play(void *, int);
static void stop(void);
static void onmove_cb(void *, int);
static int delay(long *);
static void flush(void);
audio_output audio_sndio = {.name = "sndio",
.help = &help,
.init = &init,
.deinit = &deinit,
.prepare = NULL,
.start = &start,
.stop = &stop,
.is_running = NULL,
.flush = &flush,
.delay = &delay,
.play = &play,
.volume = NULL,
.parameters = NULL,
.mute = NULL};
static pthread_mutex_t sndio_mutex = PTHREAD_MUTEX_INITIALIZER;
static struct sio_hdl *hdl;
static int framesize;
static size_t played;
static size_t written;
int64_t time_of_last_onmove_cb;
int at_least_one_onmove_cb_seen;
struct sio_par par;
struct sndio_formats {
const char *name;
enum sps_format_t fmt;
unsigned int rate;
unsigned int bits;
unsigned int bps;
unsigned int sig;
unsigned int le;
};
static struct sndio_formats formats[] = {{"S8", SPS_FORMAT_S8, 44100, 8, 1, 1, SIO_LE_NATIVE},
{"U8", SPS_FORMAT_U8, 44100, 8, 1, 0, SIO_LE_NATIVE},
{"S16", SPS_FORMAT_S16, 44100, 16, 2, 1, SIO_LE_NATIVE},
{"AUTOMATIC", SPS_FORMAT_S16, 44100, 16, 2, 1, SIO_LE_NATIVE}, // TODO: make this really automatic?
{"S24", SPS_FORMAT_S24, 44100, 24, 4, 1, SIO_LE_NATIVE},
{"S24_3LE", SPS_FORMAT_S24_3LE, 44100, 24, 3, 1, 1},
{"S24_3BE", SPS_FORMAT_S24_3BE, 44100, 24, 3, 1, 0},
{"S32", SPS_FORMAT_S32, 44100, 24, 4, 1, SIO_LE_NATIVE}};
static void help() { printf(" -d output-device set the output device [default*|...]\n"); }
static int init(int argc, char **argv) {
int found, opt, round, rate, bufsz;
unsigned int i;
const char *devname, *tmp;
// set up default values first
sio_initpar(&par);
par.rate = 44100;
par.pchan = 2;
par.bits = 16;
par.bps = SIO_BPS(par.bits);
par.le = 1;
par.sig = 1;
devname = SIO_DEVANY;
config.audio_backend_buffer_desired_length = 1.0;
config.audio_backend_buffer_interpolation_threshold_in_seconds =
0.25; // below this, soxr interpolation will not occur -- it'll be basic interpolation
// instead.
config.audio_backend_latency_offset = 0;
// get settings from settings file
// do the "general" audio options. Note, these options are in the "general" stanza!
parse_general_audio_options();
// get the specific settings
if (config.cfg != NULL) {
if (!config_lookup_string(config.cfg, "sndio.device", &devname))
devname = SIO_DEVANY;
if (config_lookup_int(config.cfg, "sndio.rate", &rate)) {
if (rate % 44100 == 0 && rate >= 44100 && rate <= 352800) {
par.rate = rate;
} else {
die("sndio: output rate must be a multiple of 44100 and 44100 <= rate <= "
"352800");
}
}
if (config_lookup_int(config.cfg, "sndio.bufsz", &bufsz)) {
if (bufsz > 0) {
par.appbufsz = bufsz;
} else {
die("sndio: bufsz must be > 0");
}
}
if (config_lookup_int(config.cfg, "sndio.round", &round)) {
if (round > 0) {
par.round = round;
} else {
die("sndio: round must be > 0");
}
}
if (config_lookup_string(config.cfg, "sndio.format", &tmp)) {
for (i = 0, found = 0; i < sizeof(formats) / sizeof(formats[0]); i++) {
if (strcasecmp(formats[i].name, tmp) == 0) {
config.output_format = formats[i].fmt;
found = 1;
break;
}
}
if (!found)
die("Invalid output format \"%s\". Should be one of: S8, U8, S16, S24, "
"S24_3LE, S24_3BE, S32, Automatic",
tmp);
}
}
optind = 1; // optind=0 is equivalent to optind=1 plus special behaviour
argv--; // so we shift the arguments to satisfy getopt()
argc++;
while ((opt = getopt(argc, argv, "d:")) > 0) {
switch (opt) {
case 'd':
devname = optarg;
break;
default:
help();
die("Invalid audio option -%c specified", opt);
}
}
if (optind < argc)
die("Invalid audio argument: %s", argv[optind]);
pthread_mutex_lock(&sndio_mutex);
debug(1, "Output device name is \"%s\".", devname);
hdl = sio_open(devname, SIO_PLAY, 0);
if (!hdl)
die("sndio: cannot open audio device");
written = played = 0;
time_of_last_onmove_cb = 0;
at_least_one_onmove_cb_seen = 0;
for (i = 0; i < sizeof(formats) / sizeof(formats[0]); i++) {
if (formats[i].fmt == config.output_format) {
par.bits = formats[i].bits;
par.bps = formats[i].bps;
par.sig = formats[i].sig;
par.le = formats[i].le;
break;
}
}
if (!sio_setpar(hdl, &par) || !sio_getpar(hdl, &par))
die("sndio: failed to set audio parameters");
for (i = 0, found = 0; i < sizeof(formats) / sizeof(formats[0]); i++) {
if (formats[i].bits == par.bits && formats[i].bps == par.bps && formats[i].sig == par.sig &&
formats[i].le == par.le && formats[i].rate == par.rate) {
config.output_format = formats[i].fmt;
found = 1;
break;
}
}
if (!found)
die("sndio: could not set output device to the required format and rate.");
framesize = par.bps * par.pchan;
config.output_rate = par.rate;
config.audio_backend_buffer_desired_length = 1.0 * par.bufsz / par.rate;
config.audio_backend_latency_offset = 0;
sio_onmove(hdl, onmove_cb, NULL);
pthread_mutex_unlock(&sndio_mutex);
return 0;
}
static void deinit() {
pthread_mutex_lock(&sndio_mutex);
sio_close(hdl);
pthread_mutex_unlock(&sndio_mutex);
}
static void start(__attribute__((unused)) int sample_rate,
__attribute__((unused)) int sample_format) {
pthread_mutex_lock(&sndio_mutex);
if (!sio_start(hdl))
die("sndio: unable to start");
written = played = 0;
time_of_last_onmove_cb = 0;
at_least_one_onmove_cb_seen = 0;
pthread_mutex_unlock(&sndio_mutex);
}
static int play(void *buf, int frames) {
if (frames > 0) {
pthread_mutex_lock(&sndio_mutex);
written += sio_write(hdl, buf, frames * framesize);
pthread_mutex_unlock(&sndio_mutex);
}
return 0;
}
static void stop() {
pthread_mutex_lock(&sndio_mutex);
if (!sio_stop(hdl))
die("sndio: unable to stop");
written = played = 0;
pthread_mutex_unlock(&sndio_mutex);
}
static void onmove_cb(__attribute__((unused)) void *arg, int delta) {
time_of_last_onmove_cb = get_absolute_time_in_fp();
at_least_one_onmove_cb_seen = 1;
played += delta;
}
static int delay(long *_delay) {
pthread_mutex_lock(&sndio_mutex);
size_t estimated_extra_frames_output = 0;
if (at_least_one_onmove_cb_seen) { // when output starts, the onmove_cb callback will be made
// calculate the difference in time between now and when the last callback occoured,
// and use it to estimate the frames that would have been output
uint64_t time_difference = get_absolute_time_in_fp() - time_of_last_onmove_cb;
uint64_t frame_difference = time_difference * par.rate;
uint64_t frame_difference_big_integer = frame_difference >> 32;
estimated_extra_frames_output = frame_difference_big_integer;
// debug(1,"Frames played to last cb: %d, estimated to current time:
// %d.",played,estimated_extra_frames_output);
}
*_delay = (written / framesize) - (played + estimated_extra_frames_output);
pthread_mutex_unlock(&sndio_mutex);
return 0;
}
static void flush() {
pthread_mutex_lock(&sndio_mutex);
if (!sio_stop(hdl) || !sio_start(hdl))
die("sndio: unable to flush");
written = played = 0;
pthread_mutex_unlock(&sndio_mutex);
}