/*
* Copyright (C) 2003-2009 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "player_thread.h"
#include "player_control.h"
#include "decoder_control.h"
#include "decoder_thread.h"
#include "output_all.h"
#include "pcm_volume.h"
#include "path.h"
#include "event_pipe.h"
#include "crossfade.h"
#include "song.h"
#include "tag.h"
#include "pipe.h"
#include "chunk.h"
#include "idle.h"
#include "main.h"
#include "buffer.h"
#include <glib.h>
#undef G_LOG_DOMAIN
#define G_LOG_DOMAIN "player_thread"
enum xfade_state {
XFADE_DISABLED = -1,
XFADE_UNKNOWN = 0,
XFADE_ENABLED = 1
};
struct player {
struct decoder_control *dc;
struct music_pipe *pipe;
/**
* are we waiting for buffered_before_play?
*/
bool buffering;
/**
* true if the decoder is starting and did not provide data
* yet
*/
bool decoder_starting;
/**
* is the player paused?
*/
bool paused;
/**
* is there a new song in pc.next_song?
*/
bool queued;
/**
* the song currently being played
*/
struct song *song;
/**
* is cross fading enabled?
*/
enum xfade_state xfade;
/**
* has cross-fading begun?
*/
bool cross_fading;
/**
* The number of chunks used for crossfading.
*/
unsigned cross_fade_chunks;
/**
* The current audio format for the audio outputs.
*/
struct audio_format play_audio_format;
/**
* The time stamp of the chunk most recently sent to the
* output thread. This attribute is only used if
* audio_output_all_get_elapsed_time() didn't return a usable
* value; the output thread can estimate the elapsed time more
* precisly.
*/
float elapsed_time;
};
static struct music_buffer *player_buffer;
static void player_command_finished_locked(void)
{
assert(pc.command != PLAYER_COMMAND_NONE);
pc.command = PLAYER_COMMAND_NONE;
g_cond_signal(main_cond);
}
static void player_command_finished(void)
{
player_lock();
player_command_finished_locked();
player_unlock();
}
/**
* Start the decoder.
*
* Player lock is not held.
*/
static void
player_dc_start(struct player *player, struct music_pipe *pipe)
{
struct decoder_control *dc = player->dc;
assert(player->queued);
assert(pc.next_song != NULL);
dc_start(dc, pc.next_song, player_buffer, pipe);
}
/**
* Stop the decoder and clears (and frees) its music pipe.
*
* Player lock is not held.
*/
static void
player_dc_stop(struct player *player)
{
struct decoder_control *dc = player->dc;
dc_stop(dc);
if (dc->pipe != NULL) {
/* clear and free the decoder pipe */
music_pipe_clear(dc->pipe, player_buffer);
if (dc->pipe != player->pipe)
music_pipe_free(dc->pipe);
dc->pipe = NULL;
}
}
/**
* Returns true if the decoder is decoding the next song (or has begun
* decoding it, or has finished doing it), and the player hasn't
* switched to that song yet.
*/
static bool
decoding_next_song(const struct player *player)
{
return player->dc->pipe != NULL && player->dc->pipe != player->pipe;
}
/**
* After the decoder has been started asynchronously, wait for the
* "START" command to finish. The decoder may not be initialized yet,
* i.e. there is no audio_format information yet.
*
* The player lock is not held.
*/
static bool
player_wait_for_decoder(struct player *player)
{
struct decoder_control *dc = player->dc;
assert(player->queued);
assert(pc.next_song != NULL);
player->queued = false;
if (decoder_lock_has_failed(dc)) {
player_lock();
pc.errored_song = dc->song;
pc.error = PLAYER_ERROR_FILE;
pc.next_song = NULL;
player_unlock();
return false;
}
player->song = pc.next_song;
player->elapsed_time = 0.0;
/* set the "starting" flag, which will be cleared by
player_check_decoder_startup() */
player->decoder_starting = true;
player_lock();
/* update player_control's song information */
pc.total_time = pc.next_song->tag != NULL
? pc.next_song->tag->time : 0;
pc.bit_rate = 0;
audio_format_clear(&pc.audio_format);
/* clear the queued song */
pc.next_song = NULL;
player_unlock();
/* call syncPlaylistWithQueue() in the main thread */
event_pipe_emit(PIPE_EVENT_PLAYLIST);
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 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.errored_song = dc->song;
pc.error = PLAYER_ERROR_FILE;
player_unlock();
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(1))
/* the output devices havn't finished playing
all chunks yet - wait for that */
return true;
player_lock();
pc.total_time = dc->total_time;
pc.audio_format = dc->in_audio_format;
player_unlock();
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.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();
player->paused = true;
return true;
}
return true;
} else {
/* the decoder is not yet ready; wait
some more */
player_wait_decoder(dc);
decoder_unlock(dc);
return true;
}
}
/**
* Sends a chunk of silence to the audio outputs. This is called when
* there is not enough decoded data in the pipe yet, to prevent
* underruns in the hardware buffers.
*
* The player lock is not held.
*/
static bool
player_send_silence(struct player *player)
{
struct music_chunk *chunk;
size_t frame_size =
audio_format_frame_size(&player->play_audio_format);
/* this formula ensures that we don't send
partial frames */
unsigned num_frames = sizeof(chunk->data) / frame_size;
assert(audio_format_defined(&player->play_audio_format));
chunk = music_buffer_allocate(player_buffer);
if (chunk == NULL) {
g_warning("Failed to allocate silence buffer");
return false;
}
#ifndef NDEBUG
chunk->audio_format = player->play_audio_format;
#endif
chunk->length = num_frames * frame_size;
memset(chunk->data, 0, chunk->length);
if (!audio_output_all_play(chunk)) {
music_buffer_return(player_buffer, chunk);
return false;
}
return true;
}
/**
* This is the handler for the #PLAYER_COMMAND_SEEK command.
*
* The player lock is not held.
*/
static bool player_seek_decoder(struct player *player)
{
struct decoder_control *dc = player->dc;
double where;
bool ret;
assert(pc.next_song != NULL);
if (decoder_current_song(dc) != pc.next_song) {
/* the decoder is already decoding the "next" song -
stop it and start the previous song again */
player_dc_stop(player);
/* clear music chunks which might still reside in the
pipe */
music_pipe_clear(player->pipe, player_buffer);
/* re-start the decoder */
player_dc_start(player, player->pipe);
ret = player_wait_for_decoder(player);
if (!ret) {
/* decoder failure */
player_command_finished();
return false;
}
} else {
pc.next_song = NULL;
player->queued = false;
}
/* wait for the decoder to complete initialization */
while (player->decoder_starting) {
ret = player_check_decoder_startup(player);
if (!ret) {
/* decoder failure */
player_command_finished();
return false;
}
}
/* send the SEEK command */
where = pc.seek_where;
if (where > pc.total_time)
where = pc.total_time - 0.1;
if (where < 0.0)
where = 0.0;
ret = dc_seek(dc, where);
if (!ret) {
/* decoder failure */
player_command_finished();
return false;
}
player->elapsed_time = where;
player_command_finished();
player->xfade = XFADE_UNKNOWN;
/* re-fill the buffer after seeking */
player->buffering = true;
audio_output_all_cancel();
return true;
}
/**
* Player lock must be held before calling.
*/
static void player_process_command(struct player *player)
{
struct decoder_control *dc = player->dc;
switch (pc.command) {
case PLAYER_COMMAND_NONE:
case PLAYER_COMMAND_STOP:
case PLAYER_COMMAND_EXIT:
case PLAYER_COMMAND_CLOSE_AUDIO:
break;
case PLAYER_COMMAND_UPDATE_AUDIO:
player_unlock();
audio_output_all_enable_disable();
player_lock();
player_command_finished_locked();
break;
case PLAYER_COMMAND_QUEUE:
assert(pc.next_song != NULL);
assert(!player->queued);
assert(dc->pipe == NULL || dc->pipe == player->pipe);
player->queued = true;
player_command_finished_locked();
break;
case PLAYER_COMMAND_PAUSE:
player_unlock();
player->paused = !player->paused;
if (player->paused) {
audio_output_all_pause();
player_lock();
pc.state = PLAYER_STATE_PAUSE;
} else if (!audio_format_defined(&player->play_audio_format)) {
/* the decoder hasn't provided an audio format
yet - don't open the audio device yet */
player_lock();
pc.state = PLAYER_STATE_PLAY;
} else if (audio_output_all_open(&player->play_audio_format, player_buffer)) {
/* unpaused, continue playing */
player_lock();
pc.state = PLAYER_STATE_PLAY;
} else {
/* the audio device has failed - rollback to
pause mode */
pc.error = PLAYER_ERROR_AUDIO;
player->paused = true;
player_lock();
}
player_command_finished_locked();
break;
case PLAYER_COMMAND_SEEK:
player_unlock();
player_seek_decoder(player);
player_lock();
break;
case PLAYER_COMMAND_CANCEL:
if (pc.next_song == NULL) {
/* the cancel request arrived too late, we're
already playing the queued song... stop
everything now */
pc.command = PLAYER_COMMAND_STOP;
return;
}
if (decoding_next_song(player)) {
/* the decoder is already decoding the song -
stop it and reset the position */
player_unlock();
player_dc_stop(player);
player_lock();
}
pc.next_song = NULL;
player->queued = false;
player_command_finished_locked();
break;
case PLAYER_COMMAND_REFRESH:
if (audio_format_defined(&player->play_audio_format) &&
!player->paused) {
player_unlock();
audio_output_all_check();
player_lock();
}
pc.elapsed_time = audio_output_all_get_elapsed_time();
if (pc.elapsed_time < 0.0)
pc.elapsed_time = player->elapsed_time;
player_command_finished_locked();
break;
}
}
static void
update_song_tag(struct song *song, const struct tag *new_tag)
{
struct tag *old_tag;
if (song_is_file(song))
/* don't update tags of local files, only remote
streams may change tags dynamically */
return;
old_tag = song->tag;
song->tag = tag_dup(new_tag);
if (old_tag != NULL)
tag_free(old_tag);
/* the main thread will update the playlist version when he
receives this event */
event_pipe_emit(PIPE_EVENT_TAG);
/* notify all clients that the tag of the current song has
changed */
idle_add(IDLE_PLAYER);
}
/**
* Plays a #music_chunk object (after applying software volume). If
* it contains a (stream) tag, copy it to the current song, so MPD's
* playlist reflects the new stream tag.
*
* Player lock is not held.
*/
static bool
play_chunk(struct song *song, struct music_chunk *chunk,
const struct audio_format *format)
{
assert(music_chunk_check_format(chunk, format));
if (chunk->tag != NULL)
update_song_tag(song, chunk->tag);
if (chunk->length == 0) {
music_buffer_return(player_buffer, chunk);
return true;
}
pc.bit_rate = chunk->bit_rate;
/* send the chunk to the audio outputs */
if (!audio_output_all_play(chunk))
return false;
pc.total_play_time += (double)chunk->length /
audio_format_time_to_size(format);
return true;
}
/**
* 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 decoder_control *dc = player->dc;
struct music_chunk *chunk = NULL;
unsigned cross_fade_position;
bool success;
if (!audio_output_all_wait(64))
/* the output pipe is still large enough, don't send
another chunk */
return true;
if (player->xfade == XFADE_ENABLED &&
decoding_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);
cross_fade_apply(chunk, other_chunk,
&dc->out_audio_format,
cross_fade_position,
player->cross_fade_chunks);
music_buffer_return(player_buffer, 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(dc);
decoder_unlock(dc);
return true;
}
}
}
if (chunk == NULL)
chunk = music_pipe_shift(player->pipe);
assert(chunk != NULL);
/* play the current chunk */
success = play_chunk(player->song, chunk, &player->play_audio_format);
if (!success) {
music_buffer_return(player_buffer, chunk);
player_lock();
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();
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;
}
/**
* This is called at the border between two songs: the audio output
* has consumed all chunks of the current song, and we should start
* sending chunks from the next one.
*
* The player lock is not held.
*
* @return true on success, false on error (playback will be stopped)
*/
static bool
player_song_border(struct player *player)
{
char *uri;
player->xfade = XFADE_UNKNOWN;
uri = song_get_uri(player->song);
g_message("played \"%s\"", uri);
g_free(uri);
music_pipe_free(player->pipe);
player->pipe = player->dc->pipe;
if (!player_wait_for_decoder(player))
return false;
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 decoder_control *dc)
{
struct player player = {
.dc = dc,
.buffering = true,
.decoder_starting = false,
.paused = false,
.queued = true,
.song = NULL,
.xfade = XFADE_UNKNOWN,
.cross_fading = false,
.cross_fade_chunks = 0,
.elapsed_time = 0.0,
};
player_unlock();
player.pipe = music_pipe_new();
player_dc_start(&player, player.pipe);
if (!player_wait_for_decoder(&player)) {
player_dc_stop(&player);
player_command_finished();
music_pipe_free(player.pipe);
event_pipe_emit(PIPE_EVENT_PLAYLIST);
player_lock();
return;
}
player_lock();
pc.state = PLAYER_STATE_PLAY;
player_command_finished_locked();
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();
audio_output_all_cancel();
break;
}
player_unlock();
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(dc);
decoder_unlock(dc);
player_lock();
continue;
} else {
/* buffering is complete */
player.buffering = false;
}
}
if (player.decoder_starting) {
/* wait until the decoder is initialized completely */
bool success;
success = player_check_decoder_startup(&player);
if (!success)
break;
player_lock();
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) {
/* 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 (decoding_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,
&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();
if (pc.command == PLAYER_COMMAND_NONE)
player_wait();
continue;
} else if (music_pipe_size(player.pipe) > 0) {
/* 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 (decoding_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_size(player.pipe) == 0)
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();
}
player_dc_stop(&player);
assert(!player.queued || pc.next_song != NULL);
pc.next_song = NULL;
music_pipe_clear(player.pipe, player_buffer);
music_pipe_free(player.pipe);
player_lock();
pc.state = PLAYER_STATE_STOP;
player_unlock();
event_pipe_emit(PIPE_EVENT_PLAYLIST);
player_lock();
}
static gpointer player_task(G_GNUC_UNUSED gpointer arg)
{
struct decoder_control dc;
dc_init(&dc);
decoder_thread_start(&dc);
player_buffer = music_buffer_new(pc.buffer_chunks);
player_lock();
while (1) {
switch (pc.command) {
case PLAYER_COMMAND_QUEUE:
assert(pc.next_song != NULL);
do_play(&dc);
break;
case PLAYER_COMMAND_STOP:
player_unlock();
audio_output_all_cancel();
player_lock();
/* fall through */
case PLAYER_COMMAND_SEEK:
case PLAYER_COMMAND_PAUSE:
pc.next_song = NULL;
player_command_finished_locked();
break;
case PLAYER_COMMAND_CLOSE_AUDIO:
player_unlock();
audio_output_all_close();
player_lock();
player_command_finished_locked();
#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();
audio_output_all_enable_disable();
player_lock();
player_command_finished_locked();
break;
case PLAYER_COMMAND_EXIT:
player_unlock();
dc_quit(&dc);
dc_deinit(&dc);
audio_output_all_close();
music_buffer_free(player_buffer);
player_command_finished();
return NULL;
case PLAYER_COMMAND_CANCEL:
pc.next_song = NULL;
player_command_finished_locked();
break;
case PLAYER_COMMAND_REFRESH:
/* no-op when not playing */
player_command_finished_locked();
break;
case PLAYER_COMMAND_NONE:
player_wait();
break;
}
}
}
void player_create(void)
{
GError *e = NULL;
assert(pc.thread == NULL);
pc.thread = g_thread_create(player_task, NULL, true, &e);
if (pc.thread == NULL)
g_error("Failed to spawn player task: %s", e->message);
}