FFmpeg/libavformat/ac3dec.c
Michael Niedermayer dd8ffc1925 Merge remote-tracking branch 'qatar/master'
* qatar/master: (47 commits)
  lavc: hide private symbols.
  lavc: deprecate img_get_alpha_info().
  lavc: use avpriv_ prefix for ff_toupper4.
  lavc: use avpriv_ prefix for ff_copy_bits and align_put_bits.
  lavc: use avpriv_ prefix for ff_ac3_parse_header.
  lavc: use avpriv_ prefix for ff_frame_rate_tab.
  lavc: rename ff_find_start_code to avpriv_mpv_find_start_code
  lavc: use avpriv_ prefix for ff_split_xiph_headers.
  lavc: use avpriv_ prefix for ff_dirac_parse_sequence_header.
  lavc: use avpriv_ prefix for some dv symbols used in lavf.
  lavc: use avpriv_ prefix for some flac symbols used in lavf.
  lavc: use avpriv_ prefix for some mpeg4audio symbols used in lavf.
  lavc: use avpriv_ prefix for some mpegaudio symbols used in lavf.
  lavc: use avpriv_ prefix for ff_aac_parse_header().
  lavf: hide private symbols.
  lavf: use avpriv_ prefix for some dv functions.
  lavf: use avpriv_ prefix for ff_new_chapter().
  avcodec: add CODEC_CAP_DELAY note to avcodec_decode_audio3() documentation
  avcodec: clarify the CODEC_CAP_DELAY note in avcodec_decode_video2()
  avcodec: clarify documentation of CODEC_CAP_DELAY
  ...

Conflicts:
	configure
	doc/general.texi
	libavcodec/Makefile
	libavcodec/aacdec.c
	libavcodec/allcodecs.c
	libavcodec/avcodec.h
	libavcodec/dv.c
	libavcodec/dvdata.c
	libavcodec/dvdata.h
	libavcodec/libspeexenc.c
	libavcodec/mpegvideo.c
	libavcodec/version.h
	libavformat/avidec.c
	libavformat/dv.c
	libavformat/dv.h
	libavformat/flvenc.c
	libavformat/mov.c
	libavformat/mp3enc.c
	libavformat/oggparsespeex.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
2011-10-21 02:01:26 +02:00

102 lines
3.1 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++) {
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>500)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",
.value = 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",
.value = CODEC_ID_EAC3,
};
#endif