/** * 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; } }