ads.c

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/*
 * ADS/SS2 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"

static int ads_probe(AVProbeData *p)
{
    if (memcmp(p->buf, "SShd", 4) ||
        memcmp(p->buf+32, "SSbd", 4))
        return 0;

    return AVPROBE_SCORE_MAX / 3 * 2;
}

static int ads_read_header(AVFormatContext *s)
{
    int align, codec, size;
    AVStream *st;

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

    avio_skip(s->pb, 8);
    st->codec->codec_type  = AVMEDIA_TYPE_AUDIO;
    codec                  = avio_rl32(s->pb);
    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;
    align                  = avio_rl32(s->pb);
    if (align <= 0 || align > INT_MAX / st->codec->channels)
        return AVERROR_INVALIDDATA;

    if (codec == 1)
        st->codec->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR;
    else
        st->codec->codec_id = AV_CODEC_ID_ADPCM_PSX;

    st->codec->block_align = st->codec->channels * align;
    avio_skip(s->pb, 12);
    size = avio_rl32(s->pb);
    if (st->codec->codec_id == AV_CODEC_ID_ADPCM_PSX)
        st->duration = (size - 0x40) / 16 / st->codec->channels * 28;
    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

    return 0;
}

static int ads_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    AVCodecContext *codec = s->streams[0]->codec;
    int ret;

    ret = av_get_packet(s->pb, pkt, codec->block_align);
    pkt->stream_index = 0;
    return ret;
}

AVInputFormat ff_ads_demuxer = {
    .name           = "ads",
    .long_name      = NULL_IF_CONFIG_SMALL("Sony PS2 ADS"),
    .read_probe     = ads_probe,
    .read_header    = ads_read_header,
    .read_packet    = ads_read_packet,
    .extensions     = "ads,ss2",
};