FFmpeg/libavformat/kvag.c
Zane van Iperen 343ccfcc4d avformat: add demuxer for Simon & Schuster Interactive's VAG format
Adds support for the custom VAG container used by some Simon & Schuster
Interactive games such as Real War, and Real War: Rogue States.

Signed-off-by: Zane van Iperen <zane@zanevaniperen.com>
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2020-02-06 17:26:22 +01:00

118 lines
3.6 KiB
C

/*
* Simon & Schuster Interactive VAG demuxer
*
* Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
*
* 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"
#include "libavutil/intreadwrite.h"
#define KVAG_TAG MKTAG('K', 'V', 'A', 'G')
#define KVAG_HEADER_SIZE 14
#define KVAG_MAX_READ_SIZE 4096
typedef struct KVAGHeader {
uint32_t magic;
uint32_t data_size;
uint32_t sample_rate;
uint16_t stereo;
} KVAGHeader;
static int kvag_probe(const AVProbeData *p)
{
if (AV_RL32(p->buf) != KVAG_TAG)
return 0;
return AVPROBE_SCORE_EXTENSION + 1;
}
static int kvag_read_header(AVFormatContext *s)
{
int ret;
AVStream *st;
KVAGHeader hdr;
AVCodecParameters *par;
uint8_t buf[KVAG_HEADER_SIZE];
if (!(st = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
if ((ret = avio_read(s->pb, buf, KVAG_HEADER_SIZE)) < 0)
return ret;
else if (ret != KVAG_HEADER_SIZE)
return AVERROR(EIO);
hdr.magic = AV_RL32(buf + 0);
hdr.data_size = AV_RL32(buf + 4);
hdr.sample_rate = AV_RL32(buf + 8);
hdr.stereo = AV_RL16(buf + 12);
par = st->codecpar;
par->codec_type = AVMEDIA_TYPE_AUDIO;
par->codec_id = AV_CODEC_ID_ADPCM_IMA_SSI;
par->format = AV_SAMPLE_FMT_S16;
if (hdr.stereo) {
par->channel_layout = AV_CH_LAYOUT_STEREO;
par->channels = 2;
} else {
par->channel_layout = AV_CH_LAYOUT_MONO;
par->channels = 1;
}
par->sample_rate = hdr.sample_rate;
par->bits_per_coded_sample = 4;
par->bits_per_raw_sample = 16;
par->block_align = 1;
par->bit_rate = par->channels *
par->sample_rate *
par->bits_per_coded_sample;
avpriv_set_pts_info(st, 64, 1, par->sample_rate);
st->start_time = 0;
st->duration = hdr.data_size *
(8 / par->bits_per_coded_sample) /
par->channels;
return 0;
}
static int kvag_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret;
AVCodecParameters *par = s->streams[0]->codecpar;
if ((ret = av_get_packet(s->pb, pkt, KVAG_MAX_READ_SIZE)) < 0)
return ret;
pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
pkt->stream_index = 0;
pkt->duration = ret * (8 / par->bits_per_coded_sample) / par->channels;
return 0;
}
AVInputFormat ff_kvag_demuxer = {
.name = "kvag",
.long_name = NULL_IF_CONFIG_SMALL("Simon & Schuster Interactive VAG"),
.read_probe = kvag_probe,
.read_header = kvag_read_header,
.read_packet = kvag_read_packet
};