ffmpeg/libavformat/vag.c

86 lines
2.5 KiB
C

/*
* 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 "internal.h"
typedef struct VAGDemuxContext {
int64_t data_end;
} VAGDemuxContext;
static int vag_probe(AVProbeData *p)
{
if (memcmp(p->buf, "VAGp\0\0\0", 7))
return 0;
return AVPROBE_SCORE_MAX;
}
static int vag_read_header(AVFormatContext *s)
{
VAGDemuxContext *c = s->priv_data;
AVStream *st;
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
avio_skip(s->pb, 4);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = AV_CODEC_ID_ADPCM_PSX;
st->codec->channels = 1 + (avio_rb32(s->pb) == 0x00000004);
avio_skip(s->pb, 4);
c->data_end = avio_rb32(s->pb);
st->duration = (c->data_end - avio_tell(s->pb)) / (16 * st->codec->channels) * 28;
st->codec->sample_rate = avio_rb32(s->pb);
if (st->codec->sample_rate <= 0)
return AVERROR_INVALIDDATA;
st->codec->block_align = 16 * st->codec->channels;
avio_skip(s->pb, 28);
avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
return 0;
}
static int vag_read_packet(AVFormatContext *s, AVPacket *pkt)
{
VAGDemuxContext *c = s->priv_data;
AVCodecContext *codec = s->streams[0]->codec;
int size;
size = FFMIN(c->data_end - avio_tell(s->pb), codec->block_align);
if (size <= 0)
return AVERROR_EOF;
return av_get_packet(s->pb, pkt, size);
}
AVInputFormat ff_vag_demuxer = {
.name = "vag",
.long_name = NULL_IF_CONFIG_SMALL("Sony VAG"),
.priv_data_size = sizeof(VAGDemuxContext),
.read_probe = vag_probe,
.read_header = vag_read_header,
.read_packet = vag_read_packet,
.extensions = "vag",
};