/**
* The decoder has acknowledged the "START" command (see
* player_wait_for_decoder()). This function checks if the decoder
* initialization has completed yet.
*
* The player lock is not held.
*/
static bool
player_check_decoder_startup(struct player *player)
{
struct player_control *pc = player->pc;
struct decoder_control *dc = player->dc;
assert(player->decoder_starting);
decoder_lock(dc);
GError *error = dc_get_error(dc);
if (error != NULL) {
/* the decoder failed */
decoder_unlock(dc);
player_lock(pc);
pc_set_error(pc, PLAYER_ERROR_DECODER, error);
player_unlock(pc);
return false;
} else if (!decoder_is_starting(dc)) {
/* the decoder is ready and ok */
decoder_unlock(dc);
if (player->output_open &&
!audio_output_all_wait(pc, 1))
/* the output devices havn't finished playing
all chunks yet - wait for that */
return true;
player_lock(pc);
pc->total_time = real_song_duration(dc->song, dc->total_time);
pc->audio_format = dc->in_audio_format;
player_unlock(pc);
player->play_audio_format = dc->out_audio_format;
player->decoder_starting = false;
if (!player->paused && !player_open_output(player)) {
char *uri = song_get_uri(dc->song);
g_warning("problems opening audio device "
"while playing \"%s\"", uri);
g_free(uri);
return true;
}
return true;
} else {
/* the decoder is not yet ready; wait
some more */
player_wait_decoder(pc, dc);
decoder_unlock(dc);
return true;
}
}
/*
* The main loop of the player thread, during playback. This is
* basically a state machine, which multiplexes data between the
* decoder thread and the output threads.
*/
static void do_play(struct player_control *pc, struct decoder_control *dc)
{
struct player player = {
.pc = pc,
.dc = dc,
.buffering = true,
.decoder_starting = false,
.paused = false,
.queued = true,
.song = NULL,
.xfade = XFADE_UNKNOWN,
.cross_fading = false,
.cross_fade_chunks = 0,
.cross_fade_tag = NULL,
.elapsed_time = 0.0,
};
player_unlock(pc);
player.pipe = music_pipe_new();
player_dc_start(&player, player.pipe);
if (!player_wait_for_decoder(&player)) {
player_dc_stop(&player);
player_command_finished(pc);
music_pipe_free(player.pipe);
event_pipe_emit(PIPE_EVENT_PLAYLIST);
player_lock(pc);
return;
}
player_lock(pc);
pc->state = PLAYER_STATE_PLAY;
player_command_finished_locked(pc);
while (true) {
player_process_command(&player);
if (pc->command == PLAYER_COMMAND_STOP ||
pc->command == PLAYER_COMMAND_EXIT ||
pc->command == PLAYER_COMMAND_CLOSE_AUDIO) {
player_unlock(pc);
audio_output_all_cancel();
break;
}
player_unlock(pc);
if (player.buffering) {
/* buffering at the start of the song - wait
until the buffer is large enough, to
prevent stuttering on slow machines */
if (music_pipe_size(player.pipe) < pc->buffered_before_play &&
!decoder_lock_is_idle(dc)) {
/* not enough decoded buffer space yet */
if (!player.paused &&
audio_format_defined(&player.play_audio_format) &&
audio_output_all_check() < 4 &&
!player_send_silence(&player))
break;
decoder_lock(dc);
/* XXX race condition: check decoder again */
player_wait_decoder(pc, dc);
decoder_unlock(dc);
player_lock(pc);
continue;
} else {
/* buffering is complete */
player.buffering = false;
}
}
if (player.decoder_starting) {
/* wait until the decoder is initialized completely */
if (!player_check_decoder_startup(&player))
break;
player_lock(pc);
continue;
}
#ifndef NDEBUG
/*
music_pipe_check_format(&play_audio_format,
player.next_song_chunk,
&dc->out_audio_format);
*/
#endif
if (decoder_lock_is_idle(dc) && player.queued &&
dc->pipe == player.pipe) {
/* the decoder has finished the current song;
make it decode the next song */
assert(dc->pipe == NULL || dc->pipe == player.pipe);
player_dc_start(&player, music_pipe_new());
}
if (player_dc_at_next_song(&player) &&
player.xfade == XFADE_UNKNOWN &&
!decoder_lock_is_starting(dc)) {
/* enable cross fading in this song? if yes,
calculate how many chunks will be required
for it */
player.cross_fade_chunks =
cross_fade_calc(pc->cross_fade_seconds, dc->total_time,
pc->mixramp_db,
pc->mixramp_delay_seconds,
dc->replay_gain_db,
dc->replay_gain_prev_db,
dc->mixramp_start,
dc->mixramp_prev_end,
&dc->out_audio_format,
&player.play_audio_format,
music_buffer_size(player_buffer) -
pc->buffered_before_play);
if (player.cross_fade_chunks > 0) {
player.xfade = XFADE_ENABLED;
player.cross_fading = false;
} else
/* cross fading is disabled or the
next song is too short */
player.xfade = XFADE_DISABLED;
}
if (player.paused) {
player_lock(pc);
if (pc->command == PLAYER_COMMAND_NONE)
player_wait(pc);
continue;
} else if (!music_pipe_empty(player.pipe)) {
/* at least one music chunk is ready - send it
to the audio output */
play_next_chunk(&player);
} else if (audio_output_all_check() > 0) {
/* not enough data from decoder, but the
output thread is still busy, so it's
okay */
/* XXX synchronize in a better way */
g_usleep(10000);
} else if (player_dc_at_next_song(&player)) {
/* at the beginning of a new song */
if (!player_song_border(&player))
break;
} else if (decoder_lock_is_idle(dc)) {
/* check the size of the pipe again, because
the decoder thread may have added something
since we last checked */
if (music_pipe_empty(player.pipe)) {
/* wait for the hardware to finish
playback */
audio_output_all_drain();
break;
}
} else {
/* the decoder is too busy and hasn't provided
new PCM data in time: send silence (if the
output pipe is empty) */
if (!player_send_silence(&player))
break;
}
player_lock(pc);
}
player_dc_stop(&player);
music_pipe_clear(player.pipe, player_buffer);
music_pipe_free(player.pipe);
if (player.cross_fade_tag != NULL)
tag_free(player.cross_fade_tag);
player_lock(pc);
if (player.queued) {
assert(pc->next_song != NULL);
pc->next_song = NULL;
}
pc->state = PLAYER_STATE_STOP;
player_unlock(pc);
event_pipe_emit(PIPE_EVENT_PLAYLIST);
player_lock(pc);
}
static gpointer
player_task(gpointer arg)
{
struct player_control *pc = arg;
struct decoder_control *dc = dc_new(pc->cond);
decoder_thread_start(dc);
player_buffer = music_buffer_new(pc->buffer_chunks);
player_lock(pc);
while (1) {
switch (pc->command) {
case PLAYER_COMMAND_QUEUE:
assert(pc->next_song != NULL);
do_play(pc, dc);
break;
case PLAYER_COMMAND_STOP:
player_unlock(pc);
audio_output_all_cancel();
player_lock(pc);
/* fall through */
case PLAYER_COMMAND_SEEK:
case PLAYER_COMMAND_PAUSE:
pc->next_song = NULL;
player_command_finished_locked(pc);
break;
case PLAYER_COMMAND_CLOSE_AUDIO:
player_unlock(pc);
audio_output_all_release();
player_lock(pc);
player_command_finished_locked(pc);
#ifndef NDEBUG
/* in the DEBUG build, check for leaked
music_chunk objects by freeing the
music_buffer */
music_buffer_free(player_buffer);
player_buffer = music_buffer_new(pc->buffer_chunks);
#endif
break;
case PLAYER_COMMAND_UPDATE_AUDIO:
player_unlock(pc);
audio_output_all_enable_disable();
player_lock(pc);
player_command_finished_locked(pc);
break;
case PLAYER_COMMAND_EXIT:
player_unlock(pc);
dc_quit(dc);
dc_free(dc);
audio_output_all_close();
music_buffer_free(player_buffer);
player_command_finished(pc);
return NULL;
case PLAYER_COMMAND_CANCEL:
pc->next_song = NULL;
player_command_finished_locked(pc);
break;
case PLAYER_COMMAND_REFRESH:
/* no-op when not playing */
player_command_finished_locked(pc);
break;
case PLAYER_COMMAND_NONE:
player_wait(pc);
break;
}
}
}
void
player_create(struct player_control *pc)
{
assert(pc->thread == NULL);
GError *e = NULL;
pc->thread = g_thread_create(player_task, pc, true, &e);
if (pc->thread == NULL)
MPD_ERROR("Failed to spawn player task: %s", e->message);
}
/**
* Obtains the next chunk from the music pipe, optionally applies
* cross-fading, and sends it to all audio outputs.
*
* @return true on success, false on error (playback will be stopped)
*/
static bool
play_next_chunk(struct player *player)
{
struct player_control *pc = player->pc;
struct decoder_control *dc = player->dc;
if (!audio_output_all_wait(pc, 64))
/* the output pipe is still large enough, don't send
another chunk */
return true;
unsigned cross_fade_position;
struct music_chunk *chunk = NULL;
if (player->xfade == XFADE_ENABLED &&
player_dc_at_next_song(player) &&
(cross_fade_position = music_pipe_size(player->pipe))
<= player->cross_fade_chunks) {
/* perform cross fade */
struct music_chunk *other_chunk =
music_pipe_shift(dc->pipe);
if (!player->cross_fading) {
/* beginning of the cross fade - adjust
crossFadeChunks which might be bigger than
the remaining number of chunks in the old
song */
player->cross_fade_chunks = cross_fade_position;
player->cross_fading = true;
}
if (other_chunk != NULL) {
chunk = music_pipe_shift(player->pipe);
assert(chunk != NULL);
assert(chunk->other == NULL);
/* don't send the tags of the new song (which
is being faded in) yet; postpone it until
the current song is faded out */
player->cross_fade_tag =
tag_merge_replace(player->cross_fade_tag,
other_chunk->tag);
other_chunk->tag = NULL;
if (isnan(pc->mixramp_delay_seconds)) {
chunk->mix_ratio = ((float)cross_fade_position)
/ player->cross_fade_chunks;
} else {
chunk->mix_ratio = nan("");
}
if (music_chunk_is_empty(other_chunk)) {
/* the "other" chunk was a music_chunk
which had only a tag, but no music
data - we cannot cross-fade that;
but since this happens only at the
beginning of the new song, we can
easily recover by throwing it away
now */
music_buffer_return(player_buffer,
other_chunk);
other_chunk = NULL;
}
chunk->other = other_chunk;
} else {
/* there are not enough decoded chunks yet */
decoder_lock(dc);
if (decoder_is_idle(dc)) {
/* the decoder isn't running, abort
cross fading */
decoder_unlock(dc);
player->xfade = XFADE_DISABLED;
} else {
/* wait for the decoder */
decoder_signal(dc);
player_wait_decoder(pc, dc);
decoder_unlock(dc);
return true;
}
}
}
if (chunk == NULL)
chunk = music_pipe_shift(player->pipe);
assert(chunk != NULL);
/* insert the postponed tag if cross-fading is finished */
if (player->xfade != XFADE_ENABLED && player->cross_fade_tag != NULL) {
chunk->tag = tag_merge_replace(chunk->tag,
player->cross_fade_tag);
player->cross_fade_tag = NULL;
}
/* play the current chunk */
if (!play_chunk(player->pc, player->song, chunk,
&player->play_audio_format)) {
music_buffer_return(player_buffer, chunk);
player_lock(pc);
pc->error = PLAYER_ERROR_AUDIO;
/* pause: the user may resume playback as soon as an
audio output becomes available */
pc->state = PLAYER_STATE_PAUSE;
player->paused = true;
player_unlock(pc);
return false;
}
/* this formula should prevent that the decoder gets woken up
with each chunk; it is more efficient to make it decode a
larger block at a time */
decoder_lock(dc);
if (!decoder_is_idle(dc) &&
music_pipe_size(dc->pipe) <= (pc->buffered_before_play +
music_buffer_size(player_buffer) * 3) / 4)
decoder_signal(dc);
decoder_unlock(dc);
return true;
}
/**
* The decoder has acknowledged the "START" command (see
* player_wait_for_decoder()). This function checks if the decoder
* initialization has completed yet.
*
* The player lock is not held.
*/
static bool
player_check_decoder_startup(struct player *player)
{
struct player_control *pc = player->pc;
struct decoder_control *dc = player->dc;
assert(player->decoder_starting);
decoder_lock(dc);
if (decoder_has_failed(dc)) {
/* the decoder failed */
decoder_unlock(dc);
player_lock(pc);
pc->errored_song = dc->song;
pc->error = PLAYER_ERROR_FILE;
player_unlock(pc);
return false;
} else if (!decoder_is_starting(dc)) {
/* the decoder is ready and ok */
decoder_unlock(dc);
if (audio_format_defined(&player->play_audio_format) &&
!audio_output_all_wait(pc, 1))
/* the output devices havn't finished playing
all chunks yet - wait for that */
return true;
player_lock(pc);
pc->total_time = real_song_duration(dc->song, dc->total_time);
pc->audio_format = dc->in_audio_format;
player_unlock(pc);
player->play_audio_format = dc->out_audio_format;
player->decoder_starting = false;
if (!player->paused &&
!audio_output_all_open(&dc->out_audio_format,
player_buffer)) {
char *uri = song_get_uri(dc->song);
g_warning("problems opening audio device "
"while playing \"%s\"", uri);
g_free(uri);
player_lock(pc);
pc->error = PLAYER_ERROR_AUDIO;
/* pause: the user may resume playback as soon
as an audio output becomes available */
pc->state = PLAYER_STATE_PAUSE;
player_unlock(pc);
player->paused = true;
return true;
}
return true;
} else {
/* the decoder is not yet ready; wait
some more */
player_wait_decoder(pc, dc);
decoder_unlock(dc);
return true;
}
}