mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-12 19:18:44 +02:00
116 lines
3.5 KiB
C
116 lines
3.5 KiB
C
/*
|
|
* raw ADTS AAC demuxer
|
|
* Copyright (c) 2008 Michael Niedermayer <michaelni@gmx.at>
|
|
* Copyright (c) 2009 Robert Swain ( rob opendot cl )
|
|
*
|
|
* 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/intreadwrite.h"
|
|
#include "avformat.h"
|
|
#include "internal.h"
|
|
#include "rawdec.h"
|
|
#include "id3v1.h"
|
|
#include "apetag.h"
|
|
|
|
static int adts_aac_probe(AVProbeData *p)
|
|
{
|
|
int max_frames = 0, first_frames = 0;
|
|
int fsize, frames;
|
|
const uint8_t *buf0 = p->buf;
|
|
const uint8_t *buf2;
|
|
const uint8_t *buf;
|
|
const uint8_t *end = buf0 + p->buf_size - 7;
|
|
|
|
buf = buf0;
|
|
|
|
for (; buf < end; buf = buf2 + 1) {
|
|
buf2 = buf;
|
|
|
|
for (frames = 0; buf2 < end; frames++) {
|
|
uint32_t header = AV_RB16(buf2);
|
|
if ((header & 0xFFF6) != 0xFFF0) {
|
|
if (buf != buf0) {
|
|
// Found something that isn't an ADTS header, starting
|
|
// from a position other than the start of the buffer.
|
|
// Discard the count we've accumulated so far since it
|
|
// probably was a false positive.
|
|
frames = 0;
|
|
}
|
|
break;
|
|
}
|
|
fsize = (AV_RB32(buf2 + 3) >> 13) & 0x1FFF;
|
|
if (fsize < 7)
|
|
break;
|
|
fsize = FFMIN(fsize, end - buf2);
|
|
buf2 += fsize;
|
|
}
|
|
max_frames = FFMAX(max_frames, frames);
|
|
if (buf == buf0)
|
|
first_frames = frames;
|
|
}
|
|
|
|
if (first_frames >= 3)
|
|
return AVPROBE_SCORE_EXTENSION + 1;
|
|
else if (max_frames > 100)
|
|
return AVPROBE_SCORE_EXTENSION;
|
|
else if (max_frames >= 3)
|
|
return AVPROBE_SCORE_EXTENSION / 2;
|
|
else if (first_frames >= 1)
|
|
return 1;
|
|
else
|
|
return 0;
|
|
}
|
|
|
|
static int adts_aac_read_header(AVFormatContext *s)
|
|
{
|
|
AVStream *st;
|
|
|
|
st = avformat_new_stream(s, NULL);
|
|
if (!st)
|
|
return AVERROR(ENOMEM);
|
|
|
|
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
|
|
st->codecpar->codec_id = s->iformat->raw_codec_id;
|
|
st->need_parsing = AVSTREAM_PARSE_FULL_RAW;
|
|
|
|
ff_id3v1_read(s);
|
|
if (s->pb->seekable &&
|
|
!av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
|
|
int64_t cur = avio_tell(s->pb);
|
|
ff_ape_parse_tag(s);
|
|
avio_seek(s->pb, cur, SEEK_SET);
|
|
}
|
|
|
|
// LCM of all possible ADTS sample rates
|
|
avpriv_set_pts_info(st, 64, 1, 28224000);
|
|
|
|
return 0;
|
|
}
|
|
|
|
AVInputFormat ff_aac_demuxer = {
|
|
.name = "aac",
|
|
.long_name = NULL_IF_CONFIG_SMALL("raw ADTS AAC (Advanced Audio Coding)"),
|
|
.read_probe = adts_aac_probe,
|
|
.read_header = adts_aac_read_header,
|
|
.read_packet = ff_raw_read_partial_packet,
|
|
.flags = AVFMT_GENERIC_INDEX,
|
|
.extensions = "aac",
|
|
.mime_type = "audio/aac,audio/aacp,audio/x-aac",
|
|
.raw_codec_id = AV_CODEC_ID_AAC,
|
|
};
|