ffmpeg/libavformat/vag.c

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/*
* VAG demuxer
* Copyright (c) 2015 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/channel_layout.h"
#include "avformat.h"
#include "demux.h"
#include "internal.h"
static int vag_probe(const AVProbeData *p)
{
if (memcmp(p->buf, "VAGp\0\0\0", 7))
return 0;
return AVPROBE_SCORE_MAX;
}
static int vag_read_header(AVFormatContext *s)
{
AVStream *st;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
avio_skip(s->pb, 4);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id = AV_CODEC_ID_ADPCM_PSX;
st->codecpar->ch_layout.nb_channels = 1 + (avio_rb32(s->pb) == 0x00000004);
avio_skip(s->pb, 4);
if (st->codecpar->ch_layout.nb_channels > 1) {
st->duration = avio_rb32(s->pb);
} else {
st->duration = avio_rb32(s->pb) / 16 * 28;
}
st->codecpar->sample_rate = avio_rb32(s->pb);
if (st->codecpar->sample_rate <= 0)
return AVERROR_INVALIDDATA;
avio_seek(s->pb, 0x1000, SEEK_SET);
if (avio_rl32(s->pb) == MKTAG('V','A','G','p')) {
st->codecpar->block_align = 0x1000 * st->codecpar->ch_layout.nb_channels;
avio_seek(s->pb, 0, SEEK_SET);
st->duration = st->duration / 16 * 28;
} else {
st->codecpar->block_align = 16 * st->codecpar->ch_layout.nb_channels;
avio_seek(s->pb, st->codecpar->ch_layout.nb_channels > 1 ? 0x80 : 0x30, SEEK_SET);
}
avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
return 0;
}
static int vag_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVCodecParameters *par = s->streams[0]->codecpar;
return av_get_packet(s->pb, pkt, par->block_align);
}
const FFInputFormat ff_vag_demuxer = {
.p.name = "vag",
.p.long_name = NULL_IF_CONFIG_SMALL("Sony PS2 VAG"),
.p.extensions = "vag",
.read_probe = vag_probe,
.read_header = vag_read_header,
.read_packet = vag_read_packet,
};