ffmpeg/libavformat/apac.c

87 lines
2.9 KiB
C

/*
* APAC demuxer
* Copyright (c) 2022 Paul B Mahol
*
* 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 "demux.h"
#include "internal.h"
#include "rawdec.h"
static int apac_probe(const AVProbeData *p)
{
if (AV_RB32(p->buf) == MKBETAG('A','P','A','C') &&
AV_RB32(p->buf + 8) == MKBETAG('P','R','O','F') &&
AV_RB32(p->buf + 12) == MKBETAG('N','A','D',' '))
return AVPROBE_SCORE_MAX;
return 0;
}
static int apac_read_header(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
uint32_t chunk_size;
AVStream *st;
int64_t pos;
avio_skip(pb, 16);
chunk_size = avio_rl32(pb);
avio_skip(pb, chunk_size);
if (avio_rb32(pb) != MKBETAG('P','F','M','T'))
return AVERROR_INVALIDDATA;
chunk_size = avio_rl32(pb);
pos = avio_tell(pb);
avio_skip(pb, 2);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = AV_CODEC_ID_APAC;
st->codecpar->ch_layout.nb_channels = avio_rl16(pb);
st->codecpar->sample_rate = avio_rl32(pb);
if (st->codecpar->ch_layout.nb_channels <= 0 ||
st->codecpar->ch_layout.nb_channels > 2 ||
st->codecpar->sample_rate <= 0)
return AVERROR_INVALIDDATA;
avio_skip(pb, 2);
st->codecpar->bits_per_coded_sample = avio_rl16(pb);
avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
avio_skip(pb, (chunk_size + pos) - avio_tell(pb) + (chunk_size & 1));
if (avio_rb32(pb) != MKBETAG('P','A','D',' '))
return AVERROR_INVALIDDATA;
avio_skip(pb, 4);
return 0;
}
const FFInputFormat ff_apac_demuxer = {
.p.name = "apac",
.p.long_name = NULL_IF_CONFIG_SMALL("raw APAC"),
.p.extensions = "apc",
.p.flags = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS,
.p.priv_class = &ff_raw_demuxer_class,
.read_probe = apac_probe,
.read_header = apac_read_header,
.read_packet = ff_raw_read_partial_packet,
.raw_codec_id = AV_CODEC_ID_APAC,
.priv_data_size = sizeof(FFRawDemuxerContext),
};