1 files changed, 512 insertions, 0 deletions

diff --git a/src/mp3_decode.c b/src/mp3_decode.c
new file mode 100644
index 00000000..086e3be1
--- /dev/null
+++ b/src/mp3_decode.c
@@ -0,0 +1,512 @@
+/* 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
+ */
+
+#ifdef HAVE_MAD
+
+#include "mp3_decode.h"
+#include "pcm_utils.h"
+#ifdef USE_MPD_MAD
+#include "libmad/mad.h"
+#else
+#include <mad.h>
+#endif
+#include "playerData.h"
+#include "log.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#define FRAMES_CUSHION		2000
+
+#define READ_BUFFER_SIZE	40960
+
+#define DECODE_BREAK		-2
+#define DECODE_CONT		-1
+#define DECODE_OK		0
+
+/* this is stolen from mpg321! */
+struct audio_dither {
+	mad_fixed_t error[3];
+	mad_fixed_t random;
+};
+
+unsigned long prng(unsigned long state) {
+	return (state * 0x0019660dL + 0x3c6ef35fL) & 0xffffffffL;
+}
+
+signed long audio_linear_dither(unsigned int bits, mad_fixed_t sample, struct audio_dither *dither) {
+	unsigned int scalebits;
+	mad_fixed_t output, mask, random;
+
+	enum {
+		MIN = -MAD_F_ONE,
+		MAX =  MAD_F_ONE - 1
+	};
+
+	sample += dither->error[0] - dither->error[1] + dither->error[2];
+
+	dither->error[2] = dither->error[1];
+	dither->error[1] = dither->error[0] / 2;
+
+	output = sample + (1L << (MAD_F_FRACBITS + 1 - bits - 1));
+
+	scalebits = MAD_F_FRACBITS + 1 - bits;
+	mask = (1L << scalebits) - 1;
+
+	random  = prng(dither->random);
+	output += (random & mask) - (dither->random & mask);
+
+	dither->random = random;
+
+	if (output > MAX) {
+		output = MAX;
+
+		if (sample > MAX)
+			sample = MAX;
+	}
+	else if (output < MIN) {
+	        output = MIN;
+
+		if (sample < MIN)
+			sample = MIN;
+	}
+
+	output &= ~mask;
+
+	dither->error[0] = sample - output;
+
+	return output >> scalebits;
+}
+/* end of stolen stuff from mpg321 */
+
+/* decoder stuff is based on madlld */
+
+typedef struct _mp3DecodeData {
+	FILE * fp;
+	struct mad_stream stream;
+	struct mad_frame frame;
+	struct mad_synth synth;
+	mad_timer_t timer;
+	unsigned char readBuffer[READ_BUFFER_SIZE];
+	char outputBuffer[CHUNK_SIZE];
+	char * outputPtr;
+	char * outputBufferEnd;
+	float totalTime;
+	float elapsedTime;
+	int muteFrame;
+	long * frameOffset;
+	mad_timer_t * times;
+	long highestFrame;
+	long currentOffset;
+	long maxFrames;
+	long currentFrame;
+	int flush;
+	unsigned long bitRate;
+} mp3DecodeData;
+
+void initMp3DecodeData(mp3DecodeData * data) {
+	data->outputPtr = data->outputBuffer;
+	data->outputBufferEnd = data->outputBuffer+CHUNK_SIZE;
+	data->muteFrame = 0;
+	data->currentOffset = 0;
+	data->highestFrame = 0;
+	data->maxFrames = 0;
+	data->frameOffset = NULL;
+	data->times = NULL;
+	data->currentFrame = 0;
+	data->flush = 1;
+	mad_stream_init(&data->stream);
+	mad_frame_init(&data->frame);
+	mad_synth_init(&data->synth);
+	mad_timer_reset(&data->timer);
+}
+
+int fillMp3InputBuffer(mp3DecodeData * data, long offset) {
+	size_t readSize;
+	size_t remaining;
+	unsigned char * readStart;
+
+	if(offset>=0) {
+		if(fseek(data->fp,offset,SEEK_SET)==0) {
+			data->currentOffset = offset;
+		}
+	}
+
+	if(offset==-1 && (data->stream).next_frame!=NULL) {
+		remaining = (data->stream).bufend-(data->stream).next_frame;
+		memmove(data->readBuffer,(data->stream).next_frame,remaining);
+		readStart = (data->readBuffer)+remaining;
+		readSize = READ_BUFFER_SIZE-remaining;
+	}
+	else {
+		readSize = READ_BUFFER_SIZE;
+		readStart = data->readBuffer,
+		remaining = 0;
+	}
+			
+	readSize = fread(readStart,1,readSize,data->fp);
+	if(readSize<=0) return -1;
+
+	data->currentOffset+=readSize;
+
+	mad_stream_buffer(&data->stream,data->readBuffer,readSize+remaining);
+	(data->stream).error = 0;
+
+	return 0;
+}
+
+int decodeNextFrameHeader(mp3DecodeData * data) {
+	if((data->stream).buffer==NULL || (data->stream).error==MAD_ERROR_BUFLEN) {
+		if(fillMp3InputBuffer(data,/*data->currentOffset*/-1) < 0) {
+			return DECODE_BREAK;
+		}
+	}
+	if(mad_header_decode(&data->frame.header,&data->stream)) {
+		if(MAD_RECOVERABLE((data->stream).error)) return DECODE_CONT;
+		else {
+			if((data->stream).error==MAD_ERROR_BUFLEN) return DECODE_CONT;
+			else
+			{
+				ERROR("unrecoverable frame level error "
+					"(%s).\n",
+					mad_stream_errorstr(&data->stream));
+				data->flush = 0;
+				return DECODE_BREAK;
+			}
+		}
+	}
+
+	return DECODE_OK;
+}
+
+int decodeNextFrame(mp3DecodeData * data) {
+	if((data->stream).buffer==NULL || (data->stream).error==MAD_ERROR_BUFLEN) {
+		if(fillMp3InputBuffer(data,/*data->currentOffset*/-1) < 0) {
+			return DECODE_BREAK;
+		}
+	}
+	if(mad_frame_decode(&data->frame,&data->stream)) {
+		if(MAD_RECOVERABLE((data->stream).error)) return DECODE_CONT;
+		else {
+			if((data->stream).error==MAD_ERROR_BUFLEN) return DECODE_CONT;
+			else
+			{
+				ERROR("unrecoverable frame level error "
+					"(%s).\n",
+					mad_stream_errorstr(&data->stream));
+				data->flush = 0;
+				return DECODE_BREAK;
+			}
+		}
+	}
+
+	return DECODE_OK;
+}
+
+/* xing stuff stolen from alsaplayer */
+# define XING_MAGIC	(('X' << 24) | ('i' << 16) | ('n' << 8) | 'g')
+
+struct xing {
+  	long flags;			/* valid fields (see below) */
+  	unsigned long frames;		/* total number of frames */
+  	unsigned long bytes;		/* total number of bytes */
+  	unsigned char toc[100];	/* 100-point seek table */
+  	long scale;			/* ?? */
+};
+
+enum {
+  	XING_FRAMES = 0x00000001L,
+  	XING_BYTES  = 0x00000002L,
+  	XING_TOC    = 0x00000004L,
+  	XING_SCALE  = 0x00000008L
+};
+
+int parse_xing(struct xing *xing, struct mad_bitptr ptr, unsigned int bitlen)
+{
+  	if (bitlen < 64 || mad_bit_read(&ptr, 32) != XING_MAGIC) goto fail;
+
+  	xing->flags = mad_bit_read(&ptr, 32);
+  	bitlen -= 64;
+
+  	if (xing->flags & XING_FRAMES) {
+    		if (bitlen < 32) goto fail;
+    		xing->frames = mad_bit_read(&ptr, 32);
+    		bitlen -= 32;
+  	}
+
+  	if (xing->flags & XING_BYTES) {
+    		if (bitlen < 32) goto fail;
+    		xing->bytes = mad_bit_read(&ptr, 32);
+    		bitlen -= 32;
+  	}
+
+  	if (xing->flags & XING_TOC) {
+    		int i;
+    		if (bitlen < 800) goto fail;
+      		for (i = 0; i < 100; ++i) xing->toc[i] = mad_bit_read(&ptr, 8);
+    		bitlen -= 800;
+  	}
+
+  	if (xing->flags & XING_SCALE) {
+    		if (bitlen < 32) goto fail;
+    		xing->scale = mad_bit_read(&ptr, 32);
+    		bitlen -= 32;
+  	}
+
+ 	 return 1;
+
+fail:
+  	xing->flags = 0;
+  	return 0;
+}
+
+int decodeFirstFrame(mp3DecodeData * data) {
+	struct stat filestat;
+	struct xing xing;
+	int ret;
+
+	memset(&xing,0,sizeof(struct xing));
+	xing.flags = 0;
+
+	while((ret = decodeNextFrameHeader(data))==DECODE_CONT);
+	if(ret!=DECODE_OK) return -1;
+	while((ret = decodeNextFrame(data))==DECODE_CONT);
+	if(ret!=DECODE_OK) return -1;
+
+	if(parse_xing(&xing,data->stream.anc_ptr,data->stream.anc_bitlen)) {
+		if(xing.flags & XING_FRAMES) {
+			mad_timer_t duration = data->frame.header.duration;
+			mad_timer_multiply(&duration,xing.frames);
+			data->muteFrame = 1;
+			data->totalTime = ((float)mad_timer_count(duration,
+						MAD_UNITS_MILLISECONDS))/1000;
+			data->maxFrames = xing.frames;
+		}
+	}
+	else {
+		mad_timer_t duration = data->frame.header.duration;
+		float frameTime = ((float)mad_timer_count(duration,
+					MAD_UNITS_MILLISECONDS))/1000;
+		fstat(fileno(data->fp),&filestat);
+		data->totalTime = (filestat.st_size*8.0)/
+					(data->frame).header.bitrate;
+		data->maxFrames = data->totalTime/frameTime+FRAMES_CUSHION;
+	}
+
+	data->frameOffset = malloc(sizeof(long)*data->maxFrames);
+	data->times = malloc(sizeof(mad_timer_t)*data->maxFrames);
+
+	return 0;
+}
+
+void mp3DecodeDataFinalize(mp3DecodeData * data) {
+	mad_synth_finish(&data->synth);
+	mad_frame_finish(&data->frame);
+	mad_stream_finish(&data->stream);
+
+	if(data->fp) fclose(data->fp);
+	if(data->frameOffset) free(data->frameOffset);
+	if(data->times) free(data->times);
+}
+
+/* this is primarily used for getting total time for tags */
+int getMp3TotalTime(char * file) {
+	mp3DecodeData data;
+	int ret;
+
+	while(!(data.fp = fopen(file,"r")) && errno==EINTR);
+	if(!data.fp) return -1;
+
+	initMp3DecodeData(&data);
+	if(decodeFirstFrame(&data)<0) ret = -1;
+	else ret = data.totalTime;
+	mp3DecodeDataFinalize(&data);
+
+	return ret;
+}
+
+int openMp3(char * file, mp3DecodeData * data) {
+	if((data->fp = fopen(file,"r"))<=0) {
+		ERROR("problems opening \"%s\"\n",file);
+		return -1;
+	}
+	initMp3DecodeData(data);
+	if(decodeFirstFrame(data)<0) {
+		mp3DecodeDataFinalize(data);
+		return -1;
+	}
+
+	return 0;
+}
+
+int mp3ChildSendData(mp3DecodeData * data, Buffer * cb, DecoderControl * dc) {
+	while(cb->begin==cb->end && cb->wrap && !dc->stop && !dc->seek) 
+		usleep(1000);
+	if(dc->stop) return -1;
+	/* just for now, so it doesn't hang */
+	if(dc->seek) return 0;
+	/* be sure to remove this! */
+
+#ifdef WORDS_BIGENDIAN
+	pcm_changeBufferEndianness(data->outputBuffer,CHUNK_SIZE,16);
+#endif
+	memcpy(cb->chunks+cb->end*CHUNK_SIZE,data->outputBuffer,CHUNK_SIZE);
+	cb->chunkSize[cb->end] = data->outputPtr-data->outputBuffer;
+	cb->bitRate[cb->end] = data->bitRate/1000;
+	cb->times[cb->end] = data->elapsedTime;
+
+	cb->end++;
+	if(cb->end>=BUFFERED_CHUNKS) {
+		cb->end = 0;
+		cb->wrap = 1;
+	}
+
+	return 0;
+}
+
+int mp3Read(mp3DecodeData * data, Buffer * cb, DecoderControl * dc) {
+	static int i;
+	static int ret;
+	static struct audio_dither dither;
+
+	if(data->currentFrame>=data->highestFrame && 
+			data->highestFrame<data->maxFrames) 
+	{
+		mad_timer_add(&data->timer,(data->frame).header.duration);
+		data->bitRate = (data->frame).header.bitrate;
+		data->frameOffset[data->currentFrame] = 
+				data->currentOffset;
+		if(data->stream.this_frame!=NULL) {
+			data->frameOffset[data->currentFrame]+= 
+					data->stream.this_frame-
+					data->stream.buffer;
+		}
+		else {
+			data->frameOffset[data->currentFrame]+= 
+					data->stream.bufend-data->stream.buffer;
+		}
+		data->times[data->currentFrame] = data->timer;
+		data->highestFrame++;
+	}
+	else data->timer = data->times[data->currentFrame];
+	data->currentFrame++;
+	data->elapsedTime = ((float)mad_timer_count(data->timer,MAD_UNITS_MILLISECONDS))/1000;
+
+	if(data->muteFrame) {
+		if(!dc->seek) data->muteFrame = 0;
+		else if(dc->seekWhere<=data->elapsedTime) {
+			data->muteFrame = 0;
+			dc->seek = 0;
+		}
+	}
+	else {
+		mad_synth_frame(&data->synth,&data->frame);
+
+		for(i=0;i<(data->synth).pcm.length;i++) {
+			signed int sample;
+	
+			sample = (signed int) audio_linear_dither(16,(data->synth).pcm.samples[0][i],&dither);
+			*(data->outputPtr++) = sample&0xff;
+			*(data->outputPtr++) = sample>>8;
+
+			if(MAD_NCHANNELS(&(data->frame).header)==2) {
+				sample = (signed int) audio_linear_dither(16,(data->synth).pcm.samples[1][i],&dither);
+				*(data->outputPtr++) = sample&0xff;
+				*(data->outputPtr++) = sample>>8;
+			}
+
+			if(data->outputPtr==data->outputBufferEnd) {
+				if(mp3ChildSendData(data,cb,dc)<0) {
+					data->flush = 0;
+					return DECODE_BREAK;
+				}
+				data->outputPtr = data->outputBuffer;
+				if(dc->seek) break;
+			}
+		}
+
+		if(dc->seek) {
+			long i = 0;
+			cb->wrap = 0;
+			cb->end = 0;
+			data->muteFrame = 1;
+			while(i<data->highestFrame && dc->seekWhere >
+					((float)mad_timer_count(data->times[i],
+					MAD_UNITS_MILLISECONDS))/1000) 
+			{
+				i++;
+			}
+			if(i<data->highestFrame) {
+				data->currentFrame = i;
+				fillMp3InputBuffer(data,data->frameOffset[i]);
+				data->muteFrame = 0;
+				dc->seek = 0;
+			}
+		}
+	}
+
+	if(data->muteFrame) {
+		while((ret=decodeNextFrameHeader(data))==DECODE_CONT);
+	}
+	else while((ret=decodeNextFrame(data))==DECODE_CONT);
+	
+	return ret;
+}
+
+void initAudioFormatFromMp3DecodeData(mp3DecodeData * data, AudioFormat * af) {
+	af->bits = 16;
+	af->sampleRate = (data->frame).header.samplerate;
+	af->channels = MAD_NCHANNELS(&(data->frame).header);
+}
+
+int mp3_decode(Buffer * cb, AudioFormat * af, DecoderControl * dc) {
+	mp3DecodeData data;
+	
+	if(openMp3(dc->file,&data) < 0) {
+		ERROR("Input does not appear to be a mp3 bit stream.\n");
+		return -1;
+	}
+
+	initAudioFormatFromMp3DecodeData(&data,af);
+	cb->totalTime = data.totalTime;
+	dc->start = 0;
+	dc->state = DECODE_STATE_DECODE;
+
+	while(mp3Read(&data,cb,dc)!=DECODE_BREAK);
+	/* send last little bit if not dc->stop */
+	if(data.outputPtr!=data.outputBuffer && data.flush)  {
+		mp3ChildSendData(&data,cb,dc);
+	}
+
+	mp3DecodeDataFinalize(&data);
+
+	if(dc->seek) dc->seek = 0;
+
+	if(dc->stop) {
+		dc->state = DECODE_STATE_STOP;
+		dc->stop = 0;
+	}
+	else dc->state = DECODE_STATE_STOP;
+		
+	return 0;
+}
+
+#endif