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