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-rw-r--r--src/mp3_decode.c512
1 files changed, 512 insertions, 0 deletions
diff --git a/src/mp3_decode.c b/src/mp3_decode.c
new file mode 100644
index 000000000..086e3be13
--- /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
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