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Ruben Gonzalez 2d8d7f8592 avformat: allow .ec3 as extension for raw E-AC-3 stream
In addition to .eac3, .ec3 is also commonly used by people to name raw
E-AC-3 streams. Enables automatic recognition of the eac3 format for
the .ac3 extension.

For instance Dolby Digital Plus software only support files with
.ec3. Files with .eac3 are not supported. Check issue  in the
public dlb_mp4base repository from DolbyLaboratories.

Signed-off-by: Ruben Gonzalez <rgonzalez@fluendo.com>
Signed-off-by: Anton Khirnov <anton@khirnov.net>
2022-08-08 16:19:38 +02:00

140 lines
4.7 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 "config_components.h"
#include "libavutil/avassert.h"
#include "libavutil/crc.h"
#include "libavcodec/ac3_parser.h"
#include "avformat.h"
#include "rawdec.h"
static int ac3_eac3_probe(const AVProbeData *p, enum AVCodecID expected_codec_id)
{
int max_frames, first_frames = 0, frames;
const uint8_t *buf, *buf2, *end;
enum AVCodecID codec_id = AV_CODEC_ID_AC3;
max_frames = 0;
buf = p->buf;
end = buf + p->buf_size;
for(; buf < end; buf++) {
if(buf > p->buf && !(buf[0] == 0x0B && buf[1] == 0x77)
&& !(buf[0] == 0x77 && buf[1] == 0x0B) )
continue;
buf2 = buf;
for(frames = 0; buf2 < end; frames++) {
uint8_t buf3[4096];
uint8_t bitstream_id;
uint16_t frame_size;
int i, ret;
if(!memcmp(buf2, "\x1\x10", 2)) {
if (buf2 + 16 > end)
break;
buf2+=16;
}
if (buf[0] == 0x77 && buf[1] == 0x0B) {
for(i=0; i<8; i+=2) {
buf3[i ] = buf2[i+1];
buf3[i+1] = buf2[i ];
}
ret = av_ac3_parse_header(buf3, 8, &bitstream_id,
&frame_size);
}else
ret = av_ac3_parse_header(buf2, end - buf2, &bitstream_id,
&frame_size);
if (ret < 0)
break;
if(buf2 + frame_size > end)
break;
if (buf[0] == 0x77 && buf[1] == 0x0B) {
av_assert0(frame_size <= sizeof(buf3));
for(i = 8; i < frame_size; i += 2) {
buf3[i ] = buf2[i+1];
buf3[i+1] = buf2[i ];
}
if (av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf3 + 2, frame_size - 2))
break;
} else {
if (av_crc(av_crc_get_table(AV_CRC_16_ANSI), 0, buf2 + 2, frame_size - 2))
break;
}
if (bitstream_id > 10)
codec_id = AV_CODEC_ID_EAC3;
buf2 += 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>=7) return AVPROBE_SCORE_EXTENSION + 1;
else if(max_frames>200)return AVPROBE_SCORE_EXTENSION;
else if(max_frames>=4) return AVPROBE_SCORE_EXTENSION/2;
else if(max_frames>=1) return 1;
else return 0;
}
#if CONFIG_AC3_DEMUXER
static int ac3_probe(const AVProbeData *p)
{
return ac3_eac3_probe(p, AV_CODEC_ID_AC3);
}
const 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 = AV_CODEC_ID_AC3,
.priv_data_size = sizeof(FFRawDemuxerContext),
.priv_class = &ff_raw_demuxer_class,
};
#endif
#if CONFIG_EAC3_DEMUXER
static int eac3_probe(const AVProbeData *p)
{
return ac3_eac3_probe(p, AV_CODEC_ID_EAC3);
}
const 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,ec3",
.raw_codec_id = AV_CODEC_ID_EAC3,
.priv_data_size = sizeof(FFRawDemuxerContext),
.priv_class = &ff_raw_demuxer_class,
};
#endif