mirror of
https://github.com/mpv-player/mpv
synced 2024-12-09 16:36:15 +00:00
174 lines
4.8 KiB
C
174 lines
4.8 KiB
C
/*
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* MP4 file format parser code
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*
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* Copyright (C) 2002 Felix Buenemann <atmosfear at users.sourceforge.net>
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* Code inspired by libmp4 from http://mpeg4ip.sourceforge.net/.
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*
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* This file is part of MPlayer.
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*
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* MPlayer is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* MPlayer is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with MPlayer; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include <stdio.h>
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#include <inttypes.h>
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#include <stdlib.h>
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#include "parse_mp4.h"
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#include "mp_msg.h"
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#include "stream/stream.h"
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//#define MP4_DUMPATOM
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#define MP4_DL MSGL_V
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#define freereturn(a,b) free(a); return b
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static int mp4_read_descr_len(stream_t *s)
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{
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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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//printf("MP4 read desc len: %d\n", length);
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return length;
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}
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/* parse the data part of MP4 esds atoms */
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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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uint16_t len;
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#ifdef MP4_DUMPATOM
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{int i;
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printf("ESDS Dump (%dbyte):\n", datalen);
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for(i = 0; i < datalen; i++)
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printf("%02X ", data[i]);
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printf("\nESDS Dumped\n");}
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#endif
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memset(esds, 0, sizeof(esds_t));
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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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if (stream_read_char(s) == MP4ESDescrTag) {
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/* read length */
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len = mp4_read_descr_len(s);
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esds->ESId = stream_read_word(s);
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esds->streamPriority = stream_read_char(s);
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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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if (len < (5 + 15)) {
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freereturn(s,1);
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}
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} else {
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esds->ESId = stream_read_word(s);
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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", 2, esds->ESId);
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}
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/* get and verify DecoderConfigDescrTab */
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if (stream_read_char(s) != MP4DecConfigDescrTag) {
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freereturn(s,1);
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}
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/* read length */
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len = mp4_read_descr_len(s);
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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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esds->decoderConfigLen=0;
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if (len < 15) {
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freereturn(s,0);
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}
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/* get and verify DecSpecificInfoTag */
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if (stream_read_char(s) != MP4DecSpecificDescrTag) {
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freereturn(s,0);
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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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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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/* get and verify SLConfigDescrTag */
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if(stream_read_char(s) != MP4SLConfigDescrTag) {
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freereturn(s,0);
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}
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/* Note: SLConfig is usually constant value 2, size 1Byte */
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esds->SLConfigLen = len = mp4_read_descr_len(s);
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esds->SLConfig = malloc(esds->SLConfigLen);
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if (esds->SLConfig) {
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stream_read(s, esds->SLConfig, esds->SLConfigLen);
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} else {
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esds->SLConfigLen = 0;
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}
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mp_msg(MSGT_DEMUX, MP4_DL,
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"ESDS MPEG4 Sync Layer Config Descriptor (%dBytes)\n"
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" -> predefined: %d\n", len, esds->SLConfig[0]);
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/* will skip the remainder of the atom */
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freereturn(s,0);
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}
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/* cleanup all mem occupied by mp4_parse_esds */
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void mp4_free_esds(esds_t *esds) {
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if(esds->decoderConfigLen)
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free(esds->decoderConfig);
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if(esds->SLConfigLen)
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free(esds->SLConfig);
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}
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#undef freereturn
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#undef MP4_DL
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