ffmpeg/libavformat/svag.c

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/*
* SVAG 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 "avformat.h"
#include "internal.h"
static int svag_probe(AVProbeData *p)
{
if (memcmp(p->buf, "Svag", 4))
return 0;
return AVPROBE_SCORE_MAX;
}
static int svag_read_header(AVFormatContext *s)
{
unsigned size, align;
AVStream *st;
avio_skip(s->pb, 4);
st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
size = avio_rl32(s->pb);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id = AV_CODEC_ID_ADPCM_PSX;
st->codec->sample_rate = avio_rl32(s->pb);
if (st->codec->sample_rate <= 0)
return AVERROR_INVALIDDATA;
st->codec->channels = avio_rl32(s->pb);
if (st->codec->channels <= 0)
return AVERROR_INVALIDDATA;
st->duration = size / (16 * st->codec->channels) * 28;
align = avio_rl32(s->pb);
if (align <= 0 || align > INT_MAX / st->codec->channels)
return AVERROR_INVALIDDATA;
st->codec->block_align = align * st->codec->channels;
avio_skip(s->pb, 0x800 - avio_tell(s->pb));
avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
return 0;
}
static int svag_read_packet(AVFormatContext *s, AVPacket *pkt)
{
AVCodecContext *codec = s->streams[0]->codec;
return av_get_packet(s->pb, pkt, codec->block_align);
}
AVInputFormat ff_svag_demuxer = {
.name = "svag",
.long_name = NULL_IF_CONFIG_SMALL("SVAG"),
.read_probe = svag_probe,
.read_header = svag_read_header,
.read_packet = svag_read_packet,
.extensions = "svag",
};