mpd/src/decode.c

/* the Music Player Daemon (MPD)
 * (c)2003-2004 by Warren Dukes (shank@mercury.chem.pitt.edu)
 * 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 "decode.h"

#include "player.h"
#include "playerData.h"
#include "utils.h"
#include "pcm_utils.h"
#include "audio.h"
#include "path.h"
#include "log.h"

#ifdef HAVE_MAD
#include "mp3_decode.h"
#endif
#ifdef HAVE_OGG
#include "ogg_decode.h"
#endif
#ifdef HAVE_FLAC
#include "flac_decode.h"
#endif
#ifdef HAVE_AUDIOFILE
#include "audiofile_decode.h"
#endif

#include <signal.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <unistd.h>
#include <string.h>

#define FADE_CHUNKS	1024

int * decode_pid = NULL;

void decodeSigHandler(int sig) {
	if(sig==SIGCHLD) {
		int status;
		if(decode_pid && *decode_pid==wait3(&status,WNOHANG,NULL)) {
			if(WIFSIGNALED(status) && WTERMSIG(status)!=SIGTERM) {
				ERROR("decode process died from a "
						"non-TERM signal: %i\n",
						WTERMSIG(status));
			}
			*decode_pid = 0;
		}
	}
	else if(sig==SIGTERM) {
		if(decode_pid) {
			int pid = *decode_pid;
			if(pid>0) kill(pid,SIGTERM);
		}
		exit(0);
	}
}

void stopDecode(DecoderControl * dc) {
	if(decode_pid && *decode_pid>0 && 
			(dc->start || dc->state==DECODE_STATE_DECODE)) 
	{
		dc->stop = 1;
		while(decode_pid && *decode_pid>0 && dc->stop) usleep(10);
	}
}

void quitDecode(PlayerControl * pc, DecoderControl * dc) {
	stopDecode(dc);
	pc->state = PLAYER_STATE_STOP;
	pc->play = 0;
	pc->stop = 0;
	pc->pause = 0;
	kill(getppid(),SIGUSR1);
}

int calculateCrossFadeChunks(PlayerControl * pc, AudioFormat * af) {
	int chunks;

	if(pc->crossFade<=0) return 0;

	chunks = (af->sampleRate*af->bits*af->channels/8.0/CHUNK_SIZE);
	chunks = (chunks*pc->crossFade+0.5);

	if(chunks>(buffered_chunks-buffered_before_play)) {
		chunks = buffered_chunks-buffered_before_play;
	}

	if(chunks<0) chunks = 0;

	return chunks;
}

int waitOnDecode(PlayerControl * pc, AudioFormat * af, DecoderControl * dc,
		Buffer * cb) 
{
	while(decode_pid && *decode_pid>0 && dc->start) usleep(10);

	if(dc->start || dc->error!=DECODE_ERROR_NOERROR) {
		strncpy(pc->erroredFile,pc->file,MAXPATHLEN);
		pc->error = PLAYER_ERROR_FILE;
		quitDecode(pc,dc);
		return -1;
	}

	if(initAudio(af)<0) {
		strncpy(pc->erroredFile,pc->file,MAXPATHLEN);
		pc->error = PLAYER_ERROR_AUDIO;
		quitDecode(pc,dc);
		return -1;
	}

	pc->elapsedTime = 0;
	pc->bitRate = 0;
	pc->sampleRate = af->sampleRate;
	pc->bits = af->bits;
	pc->channels = af->channels;
	pc->totalTime = cb->totalTime;

	return 0;
}

void decodeSeek(PlayerControl * pc, AudioFormat * af, DecoderControl * dc, 
		Buffer * cb) 
{
	if(decode_pid && *decode_pid>0) {
		cb->next = -1;
		if(dc->state!=DECODE_STATE_DECODE || dc->error || 
				strcmp(dc->file,pc->file)!=0) 
		{
			stopDecode(dc);
			cb->end = 0;
			dc->error = 0;
			dc->start = 1;
			dc->error = 0;
			waitOnDecode(pc,af,dc,cb);
		}
		if(*decode_pid>0 && dc->state==DECODE_STATE_DECODE) {
			dc->seekWhere = pc->seekWhere > pc->totalTime-1 ?
						pc->totalTime-1 : pc->seekWhere;
			dc->seekWhere = 1 > dc->seekWhere ? 1 : dc->seekWhere;
			cb->begin = 0;
			dc->seek = 1;
			pc->elapsedTime = dc->seekWhere;
			pc->bitRate = 0;
			while(*decode_pid>0 && dc->seek) usleep(10);
		}
	}
	pc->seek = 0;
}

#define processDecodeInput() \
	if(pc->lockQueue) { \
		pc->queueLockState = PLAYER_QUEUE_LOCKED; \
		pc->lockQueue = 0; \
	} \
	if(pc->unlockQueue) { \
		pc->queueLockState = PLAYER_QUEUE_UNLOCKED; \
		pc->unlockQueue = 0; \
	} \
	if(pc->pause) { \
		pause = !pause; \
		if(pause) pc->state = PLAYER_STATE_PAUSE; \
		else pc->state = PLAYER_STATE_PLAY; \
		pc->pause = 0; \
		kill(getppid(),SIGUSR1); \
	} \
	if(pc->seek) { \
		pc->totalPlayTime+= pc->elapsedTime-pc->beginTime; \
		decodeSeek(pc,af,dc,cb); \
		pc->beginTime = pc->elapsedTime; \
		doCrossFade = 0; \
		nextChunk =  -1; \
		bbp = 0; \
	} \
	if(pc->stop) { \
		pc->totalPlayTime+= pc->elapsedTime-pc->beginTime; \
		quitDecode(pc,dc); \
		return; \
	}

int decoderInit(PlayerControl * pc, Buffer * cb, AudioFormat *af, 
			DecoderControl * dc) {
	decode_pid = &(pc->decode_pid);
	*decode_pid = fork();

	if(*decode_pid==0) {
		/* CHILD */

		while(1) {
			if(dc->start) {
				strncpy(dc->file,pc->file,MAXPATHLEN);
				switch(pc->decodeType) {
#ifdef HAVE_MAD
				case DECODE_TYPE_MP3:
					dc->error = mp3_decode(cb,af,dc);
					break;
#endif
#ifdef HAVE_OGG
				case DECODE_TYPE_OGG:
					dc->error = ogg_decode(cb,af,dc);
					break;
#endif
#ifdef HAVE_FLAC
				case DECODE_TYPE_FLAC:
					dc->error = flac_decode(cb,af,dc);
					break;
#endif
#ifdef HAVE_AUDIOFILE
				case DECODE_TYPE_AUDIOFILE:
					dc->error = audiofile_decode(cb,af,dc);
					break;
#endif
				default:
					dc->error = DECODE_ERROR_UNKTYPE;
				}
				if(dc->error!=DECODE_ERROR_NOERROR) {
					dc->start = 0;
					dc->stop = 0;
					dc->state = DECODE_STATE_STOP;
				}
			}
			else if(dc->stop) {
				dc->state = DECODE_STATE_STOP;
				dc->stop = 0;
			}
			else if(dc->seek) dc->start = 1;
			else usleep(1000);
		}

		exit(0);
		/* END OF CHILD */
	}
	else if(*decode_pid<0) {
		strncpy(pc->erroredFile,pc->file,MAXPATHLEN);
		pc->error = PLAYER_ERROR_SYSTEM;
		return -1;
	}

	return 0;
}

/* decode w/ buffering
 * this will fork another process
 * child process does decoding
 * parent process does playing audio
 */
void decode() {
	Buffer * cb;
	PlayerControl * pc;
	AudioFormat * af;
	DecoderControl * dc;

	cb = &(getPlayerData()->buffer);

	cb->begin = 0;
	cb->end = 0;
	cb->wrap = 0;
	pc = &(getPlayerData()->playerControl);
	dc = &(getPlayerData()->decoderControl);
	af = &(getPlayerData()->audioFormat);
	dc->error = 0;
	dc->start = 1;
	cb->next = -1;

	if(decode_pid==NULL || *decode_pid<=0) {
		if(decoderInit(pc,cb,af,dc)<0) return;
	}

	{
		/* PARENT */
		char silence[CHUNK_SIZE];
		int pause = 0;
		int quit = 0;
		int bbp = buffered_before_play;
		int doCrossFade = 0;
		int crossFadeChunks = 0;
		int fadePosition;
		int nextChunk = -1;
		int test;

		memset(silence,0,CHUNK_SIZE);

		if(waitOnDecode(pc,af,dc,cb)<0) return;

		pc->state = PLAYER_STATE_PLAY;
		pc->play = 0;
		pc->beginTime = pc->elapsedTime;
		kill(getppid(),SIGUSR1);
	
		while(*decode_pid>0 && !cb->wrap && cb->end-cb->begin<bbp && 
				dc->state==DECODE_STATE_DECODE) 
		{
			processDecodeInput();
			if(quit) return;
			usleep(100);
		}

		while(!quit) {
			processDecodeInput();
			if(dc->state==DECODE_STATE_STOP && 
				pc->queueState==PLAYER_QUEUE_FULL &&
				pc->queueLockState==PLAYER_QUEUE_UNLOCKED) 
			{
				cb->next = cb->end;
				dc->start = 1;
				pc->queueState = PLAYER_QUEUE_DECODE;
				kill(getppid(),SIGUSR1);
			}
			if(cb->next>=0 && doCrossFade==0 && !dc->start) {
				nextChunk = -1;
				if(isCurrentAudioFormat(af)) {
					doCrossFade = 1;
					crossFadeChunks = 
						calculateCrossFadeChunks(pc,af);
					if(!crossFadeChunks ||
						pc->crossFade>=cb->totalTime) 
					{
						doCrossFade = -1;
					}
				}
				else doCrossFade = -1;
			}
			if(pause) playAudio(silence,CHUNK_SIZE);
			else if((cb->begin!=cb->end || cb->wrap) && 
				cb->begin!=cb->next)
			{
				if(doCrossFade==1 && cb->next>=0 && 
					((cb->next>cb->begin && 
					(fadePosition=cb->next-cb->begin)
					<=crossFadeChunks) || 
					(cb->begin>cb->next &&
					(fadePosition=cb->next-cb->begin+
					buffered_chunks)<=crossFadeChunks)))
				{
					if(nextChunk<0) {
						crossFadeChunks = fadePosition;
					}
					nextChunk = cb->begin+crossFadeChunks;
					test = cb->end;
					if(cb->wrap) test+=buffered_chunks;
					if(nextChunk<test) {
						if(nextChunk>=buffered_chunks)
						{
							nextChunk-=
								buffered_chunks;
						}
						pcm_mix(cb->chunks+cb->begin*
							CHUNK_SIZE,
							cb->chunks+nextChunk*
							CHUNK_SIZE,
							cb->chunkSize[
								cb->begin],
							cb->chunkSize[
								nextChunk],
							af,
							((float)fadePosition)/
							crossFadeChunks);
						if(cb->chunkSize[nextChunk]>
							cb->chunkSize[cb->begin]
							)
						{
							cb->chunkSize[cb->begin]
								= cb->chunkSize
								[nextChunk];
						}
					}
					else {
						if(dc->state==DECODE_STATE_STOP)
						{
							doCrossFade = -1;
						}
						else {
							usleep(10);
							continue;
						}
					}
				}
				pc->elapsedTime = cb->times[cb->begin];
				pc->bitRate = cb->bitRate[cb->begin];
				pcm_volumeChange(cb->chunks+cb->begin*
					CHUNK_SIZE,
					cb->chunkSize[cb->begin],
					af,
					pc->softwareVolume);
				playAudio(cb->chunks+cb->begin*CHUNK_SIZE,
					cb->chunkSize[cb->begin]);
				cb->begin++;
				if(cb->begin>=buffered_chunks) {
					cb->begin = 0;
					cb->wrap = 0;
				}
			}
			else if(cb->next==cb->begin) {
				pc->totalPlayTime+= pc->elapsedTime-
							pc->beginTime;
				if(doCrossFade==1 && nextChunk>=0) {
					nextChunk = cb->begin+crossFadeChunks;
					test = cb->end;
					if(cb->wrap) test+=buffered_chunks;
					if(nextChunk<test) {
						if(nextChunk>=buffered_chunks)
						{
							nextChunk-=
								buffered_chunks;
						}
						cb->begin = nextChunk;
					}	
				}
				while(pc->queueState==PLAYER_QUEUE_DECODE ||
					pc->queueLockState==PLAYER_QUEUE_LOCKED)
				{
					processDecodeInput();
					if(quit) {
						quitDecode(pc,dc);
						return;
					}
					usleep(10);
				}
				if(pc->queueState!=PLAYER_QUEUE_PLAY) {
					quit = 1;
					break;
				}
				else {
					cb->next = -1;
					if(waitOnDecode(pc,af,dc,cb)<0) return;
					nextChunk = -1;
					doCrossFade = 0;
					crossFadeChunks = 0;
					pc->queueState = PLAYER_QUEUE_EMPTY;
					kill(getppid(),SIGUSR1);
				}
				pc->beginTime = cb->times[cb->begin];
			}
			else if(*decode_pid<=0 || 
				(dc->state==DECODE_STATE_STOP && !dc->start)) 
			{
				quit = 1;
				break;
			}
			else usleep(10);
		}

		pc->totalPlayTime+= pc->elapsedTime-pc->beginTime; \
		quitDecode(pc,dc);

		/* END OF PARENT */
	}

	return;
}