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/* parse_mp4.c - MP4 file format parser code
* This file is part of MPlayer, see http://mplayerhq.hu/ for info.
* (c)2002 by Felix Buenemann <atmosfear at users.sourceforge.net>
* File licensed under the GPL, see http://www.fsf.org/ for more info.
* Code inspired by libmp4 from http://mpeg4ip.sourceforge.net/.
*/
#include <stdio.h>
#include <inttypes.h>
#include <malloc.h>
#include "parse_mp4.h"
#include "mp_msg.h"
#include "stream.h"
#define MP4_DL MSGL_V
#define freereturn(a,b) free(a); return b
int mp4_read_descr_len(stream_t *s) {
uint8_t b;
uint8_t numBytes = 0;
uint32_t length = 0;
do {
b = stream_read_char(s);
numBytes++;
length = (length << 7) | (b & 0x7F);
} while ((b & 0x80) && numBytes < 4);
return length;
}
int mp4_parse_esds(unsigned char *data, int datalen, esds_t *esds) {
/* create memory stream from data */
stream_t *s = new_memory_stream(data, datalen);
uint8_t tag;
uint8_t len;
esds->version = stream_read_char(s);
esds->flags = stream_read_int24(s);
mp_msg(MSGT_DEMUX, MP4_DL,
"ESDS MPEG4 version: %d flags: 0x%06X\n",
esds->version, esds->flags);
/* get and verify ES_DescrTag */
tag = stream_read_char(s);
if (tag == MP4ESDescrTag) {
/* read length */
if ((len = mp4_read_descr_len(s)) < 5 + 15) {
freereturn(s,1);
}
esds->ESId = stream_read_word(s);
esds->streamPriority = stream_read_char(s);
} else {
#if 1 /* 1 == guessed */
esds->ESId = stream_read_word(s);
#else
/* skip 2 bytes */
stream_skip(s, 2);
#endif
}
mp_msg(MSGT_DEMUX, MP4_DL,
"ESDS MPEG4 ES Descriptor (%dBytes):\n"
" -> ESId: %d\n"
" -> streamPriority: %d\n",
len, esds->ESId, esds->streamPriority);
/* get and verify DecoderConfigDescrTab */
if (stream_read_char(s) != MP4DecConfigDescrTag) {
freereturn(s,1);
}
/* read length */
if ((len = mp4_read_descr_len(s)) < 15) {
freereturn(s,1);
}
esds->objectTypeId = stream_read_char(s);
esds->streamType = stream_read_char(s);
esds->bufferSizeDB = stream_read_int24(s);
esds->maxBitrate = stream_read_dword(s);
esds->avgBitrate = stream_read_dword(s);
mp_msg(MSGT_DEMUX, MP4_DL,
"ESDS MPEG4 Decoder Config Descriptor (%dBytes):\n"
" -> objectTypeId: %d\n"
" -> streamType: 0x%02X\n"
" -> bufferSizeDB: 0x%06X\n"
" -> maxBitrate: %.3fkbit/s\n"
" -> avgBitrate: %.3fkbit/s\n",
len, esds->objectTypeId, esds->streamType,
esds->bufferSizeDB, esds->maxBitrate/1000.0,
esds->avgBitrate/1000.0);
/* get and verify DecSpecificInfoTag */
if (stream_read_char(s) != MP4DecSpecificDescrTag) {
freereturn(s,1);
}
/* read length */
esds->decoderConfigLen = len = mp4_read_descr_len(s);
esds->decoderConfig = malloc(esds->decoderConfigLen);
if (esds->decoderConfig) {
stream_read(s, esds->decoderConfig, esds->decoderConfigLen);
} else {
esds->decoderConfigLen = 0;
}
mp_msg(MSGT_DEMUX, MP4_DL,
"ESDS MPEG4 Decoder Specific Descriptor (%dBytes)\n", len);
/* will skip the remainder of the atom */
freereturn(s,0);
}
#undef freereturn
#undef MP4_DL
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