FFmpeg/libavformat/fwse.c

/*
 * FWSE demuxer
 * Copyright (c) 2020 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 "libavutil/intreadwrite.h"
#include "avformat.h"
#include "internal.h"
#include "pcm.h"

static int fwse_probe(const AVProbeData *p)
{
    if (AV_RL32(p->buf) != MKTAG('F','W','S','E'))
        return 0;
    if (AV_RL32(p->buf+4) != 2 && AV_RL32(p->buf+4) != 3)
        return 0;
    if (AV_RL32(p->buf+16) != 1 && AV_RL32(p->buf+16) != 2)
        return 0;

    return AVPROBE_SCORE_MAX / 4 * 3;
}

static int fwse_read_header(AVFormatContext *s)
{
    unsigned start_offset, version;
    AVIOContext *pb = s->pb;
    AVCodecParameters *par;
    AVStream *st;

    avio_skip(pb, 4);
    version = avio_rl32(pb);
    if (version != 2 && version != 3)
        return AVERROR_INVALIDDATA;
    avio_skip(pb, 4);
    start_offset = avio_rl32(pb);

    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);

    par              = st->codecpar;
    par->codec_type  = AVMEDIA_TYPE_AUDIO;
    par->codec_id    = AV_CODEC_ID_ADPCM_IMA_MTF;
    par->format      = AV_SAMPLE_FMT_S16;
    par->channels    = avio_rl32(pb);
    if (par->channels != 1 && par->channels != 2)
        return AVERROR_INVALIDDATA;
    if (par->channels == 1)
        par->channel_layout = AV_CH_LAYOUT_MONO;
    else if (par->channels == 2)
        par->channel_layout = AV_CH_LAYOUT_STEREO;
    st->duration = avio_rl32(pb);
    par->sample_rate = avio_rl32(pb);
    if (par->sample_rate <= 0 || par->sample_rate > INT_MAX)
        return AVERROR_INVALIDDATA;

    par->block_align = 1;
    avio_skip(pb, start_offset - avio_tell(pb));

    avpriv_set_pts_info(st, 64, 1, par->sample_rate);

    return 0;
}

const AVInputFormat ff_fwse_demuxer = {
    .name           = "fwse",
    .long_name      = NULL_IF_CONFIG_SMALL("Capcom's MT Framework sound"),
    .read_probe     = fwse_probe,
    .read_header    = fwse_read_header,
    .read_packet    = ff_pcm_read_packet,
    .extensions     = "fwse",
};