/*

 * DC STR 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 "demux.h"

#include "internal.h"

static int dcstr_probe(const AVProbeData *p)

{

    if (p->buf_size < 224 || memcmp(p->buf + 213, "Sega Stream", 11))

        return 0;

    return AVPROBE_SCORE_MAX;

}

static int dcstr_read_header(AVFormatContext *s)

{

    unsigned codec, align;

    int mult;

    AVStream *st;

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;

    st->codecpar->ch_layout.nb_channels = avio_rl32(s->pb);

    st->codecpar->sample_rate = avio_rl32(s->pb);

    if (st->codecpar->sample_rate <= 0)

        return AVERROR_INVALIDDATA;

    codec                  = avio_rl32(s->pb);

    align                  = avio_rl32(s->pb);

    avio_skip(s->pb, 4);

    st->duration           = avio_rl32(s->pb);

    mult                   = avio_rl32(s->pb);

    if (st->codecpar->ch_layout.nb_channels <= 0 || mult <= 0 ||

        mult > INT_MAX / st->codecpar->ch_layout.nb_channels) {

        av_log(s, AV_LOG_ERROR, "invalid number of channels %d x %d\n",

               st->codecpar->ch_layout.nb_channels, mult);

        return AVERROR_INVALIDDATA;

    }

    st->codecpar->ch_layout.nb_channels *= mult;

    if (!align || align > INT_MAX / st->codecpar->ch_layout.nb_channels)

        return AVERROR_INVALIDDATA;

    st->codecpar->block_align = align * st->codecpar->ch_layout.nb_channels;

    switch (codec) {

    case  4: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_AICA;       break;

    case 16: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;

    default: avpriv_request_sample(s, "codec %X", codec);

             return AVERROR_PATCHWELCOME;

    }

    avio_skip(s->pb, 0x800 - avio_tell(s->pb));

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

    return 0;

}

static int dcstr_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    AVCodecParameters *par    = s->streams[0]->codecpar;

    return av_get_packet(s->pb, pkt, par->block_align);

}

const FFInputFormat ff_dcstr_demuxer = {

    .p.name         = "dcstr",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Sega DC STR"),

    .p.extensions   = "str",

    .p.flags        = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK | AVFMT_NOBINSEARCH,

    .read_probe     = dcstr_probe,

    .read_header    = dcstr_read_header,

    .read_packet    = dcstr_read_packet,

};