• Marc Pavot's avatar
    player: set elapsed=0 at song change · fd114414
    Marc Pavot authored
    I have found something that looks like a bug in MPD:
    - When a song is finished, the next one is played and the 'player'
      event is emitted.
    - When the client sends the status command just after this event, the
      songid is the new one but the 'elapsed' time is not reseted to 0.
    
    This is problem because I have implemented the solution using a timer
    on client side to compute the elapsed time but with this bug the
    elapsed time continues to be incremented on a new song.
    fd114414
player_thread.c 12.8 KB
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544
/* the Music Player Daemon (MPD)
 * Copyright (C) 2003-2007 by Warren Dukes (warren.dukes@gmail.com)
 * This project's homepage is: 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "player_thread.h"
#include "player_control.h"
#include "decoder_control.h"
#include "audio.h"
#include "pcm_utils.h"
#include "path.h"
#include "log.h"
#include "main_notify.h"
#include "crossfade.h"
#include "song.h"
#include "pipe.h"
#include "idle.h"

#include <glib.h>

enum xfade_state {
	XFADE_DISABLED = -1,
	XFADE_UNKNOWN = 0,
	XFADE_ENABLED = 1
};

struct player {
	/**
	 * 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;

	/**
	 * index of the first chunk of the next song, -1 if there is
	 * no next song
	 */
	int next_song_chunk;
};

static void player_command_finished(void)
{
	assert(pc.command != PLAYER_COMMAND_NONE);

	pc.command = PLAYER_COMMAND_NONE;
	wakeup_main_task();
}

static void player_stop_decoder(void)
{
	dc_stop(&pc.notify);
	pc.state = PLAYER_STATE_STOP;
	wakeup_main_task();
}

static int player_wait_for_decoder(struct player *player)
{
	dc_command_wait(&pc.notify);

	if (decoder_has_failed()) {
		assert(dc.next_song == NULL || dc.next_song->url != NULL);
		pc.errored_song = dc.next_song;
		pc.error = PLAYER_ERROR_FILE;
		return -1;
	}

	pc.total_time = pc.next_song->tag != NULL
		? pc.next_song->tag->time : 0;
	pc.bit_rate = 0;
	audio_format_clear(&pc.audio_format);

	player->song = pc.next_song;
	pc.next_song = NULL;
	pc.elapsed_time = 0;
	player->queued = false;
	player->decoder_starting = true;

	return 0;
}

static bool player_seek_decoder(struct player *player)
{
	double where;
	bool ret;

	if (decoder_current_song() != pc.next_song) {
		dc_stop(&pc.notify);
		player->next_song_chunk = -1;
		music_pipe_clear();
		dc_start_async(pc.next_song);
		player_wait_for_decoder(player);
	}

	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(&pc.notify, where);
	if (ret)
		pc.elapsed_time = where;

	player_command_finished();

	return ret;
}

static void player_process_command(struct player *player)
{
	switch (pc.command) {
	case PLAYER_COMMAND_NONE:
	case PLAYER_COMMAND_PLAY:
	case PLAYER_COMMAND_STOP:
	case PLAYER_COMMAND_EXIT:
	case PLAYER_COMMAND_CLOSE_AUDIO:
		break;

	case PLAYER_COMMAND_QUEUE:
		assert(pc.next_song != NULL);
		assert(!player->queued);
		assert(player->next_song_chunk == -1);

		player->queued = true;
		player_command_finished();
		break;

	case PLAYER_COMMAND_PAUSE:
		player->paused = !player->paused;
		if (player->paused) {
			audio_output_pause_all();
			pc.state = PLAYER_STATE_PAUSE;
		} else {
			if (openAudioDevice(NULL)) {
				pc.state = PLAYER_STATE_PLAY;
			} else {
				char tmp[MPD_PATH_MAX];
				assert(dc.next_song == NULL || dc.next_song->url != NULL);
				pc.errored_song = dc.next_song;
				pc.error = PLAYER_ERROR_AUDIO;
				ERROR("problems opening audio device "
				      "while playing \"%s\"\n",
				      song_get_url(dc.next_song, tmp));
				player->paused = true;
			}
		}
		player_command_finished();
		break;

	case PLAYER_COMMAND_SEEK:
		dropBufferedAudio();
		if (player_seek_decoder(player)) {
			player->xfade = XFADE_UNKNOWN;

			/* abort buffering when the user has requested
			   a seek */
			player->buffering = false;
		}
		break;

	case PLAYER_COMMAND_CANCEL:
		if (pc.next_song == NULL) {
			/* the cancel request arrived too later, we're
			   already playing the queued song...  stop
			   everything now */
			pc.command = PLAYER_COMMAND_STOP;
			return;
		}

		if (player->next_song_chunk != -1) {
			/* the decoder is already decoding the song -
			   stop it and reset the position */
			dc_stop(&pc.notify);
			music_pipe_chop(player->next_song_chunk);
			player->next_song_chunk = -1;
		}

		pc.next_song = NULL;
		player->queued = false;
		player_command_finished();
		break;
	}
}

static int
play_chunk(struct song *song, struct music_chunk *chunk,
	   const struct audio_format *format, double sizeToTime)
{
	pc.elapsed_time = chunk->times;
	pc.bit_rate = chunk->bit_rate;

	if (chunk->tag != NULL) {
		sendMetadataToAudioDevice(chunk->tag);

		if (!song_is_file(song)) {
			/* always update the tag of remote streams */
			struct tag *old_tag = song->tag;

			song->tag = tag_dup(chunk->tag);

			if (old_tag != NULL)
				tag_free(old_tag);

			/* notify all clients that the tag of the
			   current song has changed */
			idle_add(IDLE_PLAYER);
		}
	}

	if (chunk->length == 0)
		return 0;

	pcm_volume(chunk->data, chunk->length,
		   format, pc.software_volume);

	if (!playAudio(chunk->data, chunk->length))
		return -1;

	pc.total_play_time += sizeToTime * chunk->length;
	return 0;
}

static void do_play(void)
{
	struct player player = {
		.buffering = true,
		.decoder_starting = false,
		.paused = false,
		.queued = false,
		.song = NULL,
		.xfade = XFADE_UNKNOWN,
		.next_song_chunk = -1,
	};
	unsigned int crossFadeChunks = 0;
	/** the position of the next cross-faded chunk in the next
	    song */
	int nextChunk = 0;
	static const char silence[CHUNK_SIZE];
	struct audio_format play_audio_format;
	double sizeToTime = 0.0;

	music_pipe_clear();
	music_pipe_set_lazy(false);

	dc_start(&pc.notify, pc.next_song);
	if (player_wait_for_decoder(&player) < 0) {
		player_stop_decoder();
		player_command_finished();
		return;
	}

	pc.elapsed_time = 0;
	pc.state = PLAYER_STATE_PLAY;
	player_command_finished();

	while (1) {
		player_process_command(&player);
		if (pc.command == PLAYER_COMMAND_STOP ||
		    pc.command == PLAYER_COMMAND_EXIT ||
		    pc.command == PLAYER_COMMAND_CLOSE_AUDIO) {
			dropBufferedAudio();
			break;
		}

		if (player.buffering) {
			if (music_pipe_available() < pc.buffered_before_play &&
			    !decoder_is_idle()) {
				/* not enough decoded buffer space yet */
				notify_wait(&pc.notify);
				continue;
			} else {
				/* buffering is complete */
				player.buffering = false;
				music_pipe_set_lazy(true);
			}
		}

		if (player.decoder_starting) {
			if (decoder_has_failed()) {
				/* the decoder failed */
				assert(dc.next_song == NULL || dc.next_song->url != NULL);
				pc.errored_song = dc.next_song;
				pc.error = PLAYER_ERROR_FILE;
				break;
			}
			else if (!decoder_is_starting()) {
				/* the decoder is ready and ok */
				player.decoder_starting = false;
				if (!openAudioDevice(&dc.out_audio_format)) {
					char tmp[MPD_PATH_MAX];
					assert(dc.next_song == NULL || dc.next_song->url != NULL);
					pc.errored_song = dc.next_song;
					pc.error = PLAYER_ERROR_AUDIO;
					ERROR("problems opening audio device "
					      "while playing \"%s\"\n",
					      song_get_url(dc.next_song, tmp));
					break;
				}

				if (player.paused)
					closeAudioDevice();

				pc.total_time = dc.total_time;
				pc.audio_format = dc.in_audio_format;
				play_audio_format = dc.out_audio_format;
				sizeToTime = audioFormatSizeToTime(&dc.out_audio_format);
			}
			else {
				/* the decoder is not yet ready; wait
				   some more */
				notify_wait(&pc.notify);
				continue;
			}
		}

#ifndef NDEBUG
		/*
		music_pipe_check_format(&play_audio_format,
					player.next_song_chunk,
					&dc.out_audio_format);
		*/
#endif

		if (decoder_is_idle() && !player.queued &&
		    player.next_song_chunk < 0 &&
		    pc.next_song != NULL &&
		    pc.command == PLAYER_COMMAND_NONE) {
			/* the decoder has finished the current song;
			   request the next song from the playlist */

			pc.next_song = NULL;
			wakeup_main_task();
		}

		if (decoder_is_idle() && player.queued) {
			/* the decoder has finished the current song;
			   make it decode the next song */
			assert(pc.next_song != NULL);
			assert(player.next_song_chunk == -1);

			player.queued = false;
			player.next_song_chunk = music_pipe_tail_index();
			dc_start_async(pc.next_song);
		}
		if (player.next_song_chunk >= 0 &&
		    player.xfade == XFADE_UNKNOWN &&
		    !decoder_is_starting()) {
			/* enable cross fading in this song?  if yes,
			   calculate how many chunks will be required
			   for it */
			crossFadeChunks =
				cross_fade_calc(pc.cross_fade_seconds, dc.total_time,
						&dc.out_audio_format,
						music_pipe_size() -
						pc.buffered_before_play);
			if (crossFadeChunks > 0) {
				player.xfade = XFADE_ENABLED;
				nextChunk = -1;
			} else
				/* cross fading is disabled or the
				   next song is too short */
				player.xfade = XFADE_DISABLED;
		}

		if (player.paused)
			notify_wait(&pc.notify);
		else if (!music_pipe_is_empty() &&
			 !music_pipe_head_is(player.next_song_chunk)) {
			struct music_chunk *beginChunk = music_pipe_peek();
			unsigned int fadePosition;
			if (player.xfade == XFADE_ENABLED &&
			    player.next_song_chunk >= 0 &&
			    (fadePosition = music_pipe_relative(player.next_song_chunk))
			    <= crossFadeChunks) {
				/* perform cross fade */
				if (nextChunk < 0) {
					/* beginning of the cross fade
					   - adjust crossFadeChunks
					   which might be bigger than
					   the remaining number of
					   chunks in the old song */
					crossFadeChunks = fadePosition;
				}
				nextChunk = music_pipe_absolute(crossFadeChunks);
				if (nextChunk >= 0) {
					music_pipe_set_lazy(true);
					cross_fade_apply(beginChunk,
							 music_pipe_get_chunk(nextChunk),
							 &dc.out_audio_format,
							 fadePosition,
							 crossFadeChunks);
				} else {
					/* there are not enough
					   decoded chunks yet */
					if (decoder_is_idle()) {
						/* the decoder isn't
						   running, abort
						   cross fading */
						player.xfade = XFADE_DISABLED;
					} else {
						/* wait for the
						   decoder */
						music_pipe_set_lazy(false);
						notify_signal(&dc.notify);
						notify_wait(&pc.notify);
						continue;
					}
				}
			}

			/* play the current chunk */
			if (play_chunk(player.song, beginChunk,
				       &play_audio_format, sizeToTime) < 0)
				break;
			music_pipe_shift();

			/* 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 */
			if (music_pipe_available() <= (pc.buffered_before_play + music_pipe_size() * 3) / 4)
				notify_signal(&dc.notify);
		} else if (music_pipe_head_is(player.next_song_chunk)) {
			/* at the beginning of a new song */

			if (player.xfade == XFADE_ENABLED && nextChunk >= 0) {
				/* the cross-fade is finished; skip
				   the section which was cross-faded
				   (and thus already played) */
				music_pipe_skip(crossFadeChunks);
			}

			player.xfade = XFADE_UNKNOWN;

			player.next_song_chunk = -1;
			if (player_wait_for_decoder(&player) < 0)
				return;

			wakeup_main_task();
		} else if (decoder_is_idle()) {
			break;
		} else {
			size_t frame_size =
				audio_format_frame_size(&play_audio_format);
			/* this formula ensures that we don't send
			   partial frames */
			unsigned num_frames = CHUNK_SIZE / frame_size;

			/*DEBUG("waiting for decoded audio, play silence\n");*/
			if (!playAudio(silence, num_frames * frame_size))
				break;
		}
	}

	player_stop_decoder();
}

static void * player_task(G_GNUC_UNUSED void *arg)
{
	while (1) {
		switch (pc.command) {
		case PLAYER_COMMAND_PLAY:
		case PLAYER_COMMAND_QUEUE:
			do_play();
			break;

		case PLAYER_COMMAND_STOP:
		case PLAYER_COMMAND_SEEK:
		case PLAYER_COMMAND_PAUSE:
			player_command_finished();
			break;

		case PLAYER_COMMAND_CLOSE_AUDIO:
			closeAudioDevice();
			player_command_finished();
			break;

		case PLAYER_COMMAND_EXIT:
			closeAudioDevice();
			player_command_finished();
			pthread_exit(NULL);
			break;

		case PLAYER_COMMAND_CANCEL:
			pc.next_song = NULL;
			player_command_finished();
			break;

		case PLAYER_COMMAND_NONE:
			notify_wait(&pc.notify);
			break;
		}
	}
	return NULL;
}

void player_create(void)
{
	pthread_attr_t attr;
	pthread_t player_thread;

	pthread_attr_init(&attr);
	pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
	if (pthread_create(&player_thread, &attr, player_task, NULL))
		FATAL("Failed to spawn player task: %s\n", strerror(errno));
}