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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavformat/ac3dec.c
Michael Niedermayer a369a6b858 Merge remote-tracking branch 'qatar/master'
* qatar/master: (29 commits)
  fate: add golomb-test
  golomb-test: K&R formatting cosmetics
  h264: Split h264-test off into a separate file - golomb-test.c.
  h264-test: cleanup: drop timer invocations, commented out code and other cruft
  h264-test: Remove unused DSP and AVCodec contexts and related init calls.
  adpcm: Add missing stdint.h #include to fix standalone header compilation.
  lavf: add functions for accessing the fourcc<->CodecID mapping tables.
  lavc: set AVCodecContext.codec in avcodec_get_context_defaults3().
  lavc: make avcodec_close() work properly on unopened codecs.
  lavc: add avcodec_is_open().
  lavf: rename AVInputFormat.value to raw_codec_id.
  lavf: remove the pointless value field from flv and iv8
  lavc/lavf: remove unnecessary symbols from the symbol version script.
  lavc: reorder AVCodec fields.
  lavf: reorder AVInput/OutputFormat fields.
  mp3dec: Fix a heap-buffer-overflow
  adpcmenc: remove some unneeded casts
  adpcmenc: use int16_t and uint8_t instead of short and unsigned char.
  adpcmenc: fix adpcm_ms extradata allocation
  adpcmenc: return proper AVERROR codes instead of -1
  ...

Conflicts:
	doc/APIchanges
	libavcodec/Makefile
	libavcodec/adpcmenc.c
	libavcodec/avcodec.h
	libavcodec/h264.c
	libavcodec/libavcodec.v
	libavcodec/mpc7.c
	libavcodec/mpegaudiodec.c
	libavcodec/options.c
	libavformat/Makefile
	libavformat/avformat.h
	libavformat/flvdec.c
	libavformat/libavformat.v

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2012-02-01 02:36:09 +01:00

104 lines
3.2 KiB
C

/*
* RAW AC-3 and E-AC-3 demuxer
* Copyright (c) 2007 Justin Ruggles <justin.ruggles@gmail.com>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/crc.h"
#include "libavcodec/ac3_parser.h"
#include "avformat.h"
#include "rawdec.h"
static int ac3_eac3_probe(AVProbeData *p, enum CodecID expected_codec_id)
{
int max_frames, first_frames = 0, frames;
uint8_t *buf, *buf2, *end;
AC3HeaderInfo hdr;
GetBitContext gbc;
enum CodecID codec_id = CODEC_ID_AC3;
max_frames = 0;
buf = p->buf;
end = buf + p->buf_size;
for(; buf < end; buf++) {
buf2 = buf;
for(frames = 0; buf2 < end; frames++) {
if(!memcmp(buf2, "\x1\x10\0\0\0\0\0\0", 8))
buf2+=16;
init_get_bits(&gbc, buf2, 54);
if(avpriv_ac3_parse_header(&gbc, &hdr) < 0)
break;
if(buf2 + hdr.frame_size > end ||
av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf2 + 2, hdr.frame_size - 2))
break;
if (hdr.bitstream_id > 10)
codec_id = CODEC_ID_EAC3;
buf2 += hdr.frame_size;
}
max_frames = FFMAX(max_frames, frames);
if(buf == p->buf)
first_frames = frames;
}
if(codec_id != expected_codec_id) return 0;
// keep this in sync with mp3 probe, both need to avoid
// issues with MPEG-files!
if (first_frames>=4) return AVPROBE_SCORE_MAX/2+1;
else if(max_frames>200)return AVPROBE_SCORE_MAX/2;
else if(max_frames>=4) return AVPROBE_SCORE_MAX/4;
else if(max_frames>=1) return 1;
else return 0;
}
#if CONFIG_AC3_DEMUXER
static int ac3_probe(AVProbeData *p)
{
return ac3_eac3_probe(p, CODEC_ID_AC3);
}
AVInputFormat ff_ac3_demuxer = {
.name = "ac3",
.long_name = NULL_IF_CONFIG_SMALL("raw AC-3"),
.read_probe = ac3_probe,
.read_header = ff_raw_audio_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags= AVFMT_GENERIC_INDEX,
.extensions = "ac3",
.raw_codec_id = CODEC_ID_AC3,
};
#endif
#if CONFIG_EAC3_DEMUXER
static int eac3_probe(AVProbeData *p)
{
return ac3_eac3_probe(p, CODEC_ID_EAC3);
}
AVInputFormat ff_eac3_demuxer = {
.name = "eac3",
.long_name = NULL_IF_CONFIG_SMALL("raw E-AC-3"),
.read_probe = eac3_probe,
.read_header = ff_raw_audio_read_header,
.read_packet = ff_raw_read_partial_packet,
.flags= AVFMT_GENERIC_INDEX,
.extensions = "eac3",
.raw_codec_id = CODEC_ID_EAC3,
};
#endif