Use an explicit 'is_running' flag in the sndio back end. Correct/impr…

…ove some sndio documentation.

audio_sndio.c

@@ -4,7 +4,7 @@
  * Copyright (c) 2017 Tobias Kortkamp <[email protected]>
  *
  * Modifications for audio synchronisation
- * and related work, copyright (c) Mike Brady 2014 -- 2022
+ * and related work, copyright (c) Mike Brady 2014 -- 2024
  * All rights reserved.
  *
  * Permission to use, copy, modify, and distribute this software for any
@@ -30,6 +30,7 @@
 
 static pthread_mutex_t sndio_mutex = PTHREAD_MUTEX_INITIALIZER;
 static struct sio_hdl *hdl;
+static int is_running;
 static int framesize;
 static size_t played;
 static size_t written;
@@ -58,7 +59,9 @@ static struct sndio_formats formats[] = {{"S8", SPS_FORMAT_S8, 44100, 8, 1, 1, S
  {"S24_3BE", SPS_FORMAT_S24_3BE, 44100, 24, 3, 1, 0},
  {"S32", SPS_FORMAT_S32, 44100, 32, 4, 1, SIO_LE_NATIVE}};
 
-static void help() { printf(" -d output-device set the output device [default*|...]\n"); }
+static void help() {
+ printf(" -d output-device set the output device [default|rsnd/0|rsnd/1...]\n");
+}
 
 void onmove_cb(__attribute__((unused)) void *arg, int delta) {
  time_of_last_onmove_cb = get_absolute_time_in_ns();
@@ -155,6 +158,7 @@ static int init(int argc, char **argv) {
  debug(1, "sndio: rate: %u.", par.rate);
  debug(1, "sndio: bits: %u.", par.bits);
 
+ is_running = 0;
  hdl = sio_open(devname, SIO_PLAY, 0);
  if (!hdl)
  die("sndio: cannot open audio device");
@@ -206,48 +210,54 @@ static int init(int argc, char **argv) {
 }
 
 static void deinit() {
- // pthread_mutex_lock(&sndio_mutex);
- pthread_cleanup_debug_mutex_lock(&sndio_mutex, 1000, 1);
- sio_close(hdl);
- // pthread_mutex_unlock(&sndio_mutex);
- pthread_cleanup_pop(1); // unlock the mutex
-}
-
-static void start(__attribute__((unused)) int sample_rate,
- __attribute__((unused)) int sample_format) {
- // pthread_mutex_lock(&sndio_mutex);
  pthread_cleanup_debug_mutex_lock(&sndio_mutex, 1000, 1);
- at_least_one_onmove_cb_seen = 0;
- // any previously-reported frame count
-
- 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);
+ if (hdl != NULL) {
+ if (is_running != 0) {
+ sio_flush(hdl);
+ is_running = 0;
+ }
+ sio_close(hdl);
+ hdl = NULL;
+ }
  pthread_cleanup_pop(1); // unlock the mutex
 }
 
 static int play(void *buf, int frames, __attribute__((unused)) int sample_type,
  __attribute__((unused)) uint32_t timestamp,
  __attribute__((unused)) uint64_t playtime) {
  if (frames > 0) {
- // pthread_mutex_lock(&sndio_mutex);
  pthread_cleanup_debug_mutex_lock(&sndio_mutex, 1000, 1);
+ if (is_running == 0) {
+ if (hdl != NULL) {
+ if (sio_start(hdl) != 1)
+ debug(1, "sndio: unable to start");
+ is_running = 1;
+ written = played = 0;
+ time_of_last_onmove_cb = 0;
+ at_least_one_onmove_cb_seen = 0;
+ } else {
+ debug(1, "sndio: output device is not open for play!");
+ }
+ }
  written += sio_write(hdl, buf, frames * framesize);
- // pthread_mutex_unlock(&sndio_mutex);
  pthread_cleanup_pop(1); // unlock the mutex
  }
  return 0;
 }
 
 static void stop() {
  pthread_cleanup_debug_mutex_lock(&sndio_mutex, 1000, 1);
-
- if (!sio_stop(hdl))
- die("sndio: unable to stop");
- written = played = 0;
+ if (hdl != NULL) {
+ if (is_running != 0) {
+ if (sio_flush(hdl) != 1)
+ debug(1, "sndio: unable to stop");
+ written = played = is_running = 0;
+ } else {
+ debug(1, "sndio: stop: not running.");
+ }
+ } else {
+ debug(1, "sndio: output device is not open for stop!");
+ }
  pthread_cleanup_pop(1); // unlock the mutex
 }
 
@@ -276,18 +286,34 @@ int get_delay(long *delay) {
 static int delay(long *delay) {
  int result = 0;
  pthread_cleanup_debug_mutex_lock(&sndio_mutex, 1000, 1);
- result = get_delay(delay);
+ if (hdl != NULL) {
+ if (is_running != 0) {
+ result = get_delay(delay);
+ } else {
+ debug(1, "sndio: output device is not open for delay!");
+ if (delay != NULL)
+ *delay = 0;
+ }
+ } else {
+ debug(1, "sndio: output device is not open for delay!");
+ }
  pthread_cleanup_pop(1); // unlock the mutex
  return result;
 }
 
 static void flush() {
- // pthread_mutex_lock(&sndio_mutex);
  pthread_cleanup_debug_mutex_lock(&sndio_mutex, 1000, 1);
- if (!sio_stop(hdl) || !sio_start(hdl))
- die("sndio: unable to flush");
- written = played = 0;
- // pthread_mutex_unlock(&sndio_mutex);
+ if (hdl != NULL) {
+ if (is_running != 0) {
+ if (sio_flush(hdl) != 1)
+ debug(1, "sndio: unable to flush");
+ written = played = is_running = 0;
+ } else {
+ debug(1, "sndio: flush: not running.");
+ }
+ } else {
+ debug(1, "sndio: output device is not open for flush!");
+ }
  pthread_cleanup_pop(1); // unlock the mutex
 }
 
@@ -296,7 +322,7 @@ audio_output audio_sndio = {.name = "sndio",
  .init = &init,
  .deinit = &deinit,
  .prepare = NULL,
- .start = &start,
+ .start = NULL,
  .stop = &stop,
  .is_running = NULL,
  .flush = &flush,

player.c

@@ -2141,9 +2141,10 @@ void *player_thread_func(void *arg) {
  if ((config.output->parameters == NULL) || (conn->input_bit_depth > output_bit_depth) ||
  (config.playback_mode == ST_mono))
  conn->enable_dither = 1;
-
- // remember, the output device may never have been initialised prior to this call
- config.output->start(config.output_rate, config.output_format); // will need a corresponding stop
+
+ // call the backend's start() function if it exists.
+ if (config.output->start != NULL)
+ config.output->start(config.output_rate, config.output_format);
 
  // we need an intermediate "transition" buffer
 

scripts/shairport-sync.conf

@@ -157,7 +157,7 @@ pw =
 // --with-sndio
 sndio =
 {
-// device = "snd/0"; // optional setting to set the name of the output device. Default is the sndio system default.
+// device = "default"; // optional setting to set the name of the output device, e.g. "rsnd/0", "rsnd/1", etc.
 // rate = 44100; // optional setting which can be 44100, 88200, 176400 or 352800, but the device must have the capability. Default is 44100.
 // format = "S16"; // optional setting which can be "U8", "S8", "S16", "S24", "S24_3LE", "S24_3BE" or "S32", but the device must have the capability. Except where stated using (*LE or *BE), endianness matches that of the processor.
 // round = <number>; // advanced optional setting to set the period size near to this value