/*

 * 3DO 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 "libavutil/intreadwrite.h"

#include "avformat.h"

#include "demux.h"

#include "internal.h"

static int threedostr_probe(const AVProbeData *p)

{

    for (int i = 0; i < p->buf_size;) {

        unsigned chunk = AV_RL32(p->buf + i);

        unsigned size  = AV_RB32(p->buf + i + 4);

        if (size < 8 || p->buf_size - i < size)

            return 0;

        i += 8;

        size -= 8;

        switch (chunk) {

        case MKTAG('C','T','R','L'):

            break;

        case MKTAG('S','N','D','S'):

            if (size < 56)

                return 0;

            i += 8;

            if (AV_RL32(p->buf + i) != MKTAG('S','H','D','R'))

                return 0;

            i += 28;

            if (AV_RB32(p->buf + i) <= 0)

                return 0;

            i += 4;

            if (AV_RB32(p->buf + i) <= 0)

                return 0;

            i += 4;

            if (AV_RL32(p->buf + i) == MKTAG('S','D','X','2'))

                return AVPROBE_SCORE_MAX;

            else

                return 0;

            break;

        case MKTAG('S','H','D','R'):

            if (size > 0x78) {

                i += 0x78;

                size -= 0x78;

            }

            break;

        default:

            break;

        }

        i += size;

    }

    return 0;

}

static int threedostr_read_header(AVFormatContext *s)

{

    unsigned chunk, codec = 0, size, ctrl_size = -1, found_shdr = 0;

    AVStream *st;

    while (!avio_feof(s->pb) && !found_shdr) {

        chunk = avio_rl32(s->pb);

        size  = avio_rb32(s->pb);

        if (size < 8)

            return AVERROR_INVALIDDATA;

        size -= 8;

        switch (chunk) {

        case MKTAG('C','T','R','L'):

            ctrl_size = size;

            break;

        case MKTAG('S','N','D','S'):

            if (size < 56)

                return AVERROR_INVALIDDATA;

            avio_skip(s->pb, 8);

            if (avio_rl32(s->pb) != MKTAG('S','H','D','R'))

                return AVERROR_INVALIDDATA;

            avio_skip(s->pb, 24);

            st = avformat_new_stream(s, NULL);

            if (!st)

                return AVERROR(ENOMEM);

            st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;

            st->codecpar->sample_rate = avio_rb32(s->pb);

            st->codecpar->ch_layout.nb_channels = avio_rb32(s->pb);

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

                return AVERROR_INVALIDDATA;

            codec                  = avio_rl32(s->pb);

            avio_skip(s->pb, 4);

            if (ctrl_size == 20 || ctrl_size == 3 || ctrl_size == -1)

                st->duration       = (avio_rb32(s->pb) - 1) / st->codecpar->ch_layout.nb_channels;

            else

                st->duration       = avio_rb32(s->pb) * 16 / st->codecpar->ch_layout.nb_channels;

            size -= 56;

            found_shdr = 1;

            break;

        case MKTAG('S','H','D','R'):

            if (size >  0x78) {

                avio_skip(s->pb, 0x74);

                size -= 0x78;

                if (avio_rl32(s->pb) == MKTAG('C','T','R','L') && size > 4) {

                    ctrl_size = avio_rb32(s->pb);

                    size -= 4;

                }

            }

            break;

        default:

            av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);

            break;

        }

        avio_skip(s->pb, size);

    }

    switch (codec) {

    case MKTAG('S','D','X','2'):

        st->codecpar->codec_id    = AV_CODEC_ID_SDX2_DPCM;

        st->codecpar->block_align = 1 * st->codecpar->ch_layout.nb_channels;

        break;

    default:

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

        return AVERROR_PATCHWELCOME;

    }

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

    return 0;

}

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

{

    unsigned chunk, size;

    AVStream *st = s->streams[0];

    int64_t pos;

    int ret = 0;

    while (!avio_feof(s->pb)) {

        pos   = avio_tell(s->pb);

        chunk = avio_rl32(s->pb);

        size  = avio_rb32(s->pb);

        if (!size)

            continue;

        if (size < 8)

            return AVERROR_INVALIDDATA;

        size -= 8;

        switch (chunk) {

        case MKTAG('S','N','D','S'):

            if (size <= 16)

                return AVERROR_INVALIDDATA;

            avio_skip(s->pb, 8);

            if (avio_rl32(s->pb) != MKTAG('S','S','M','P'))

                return AVERROR_INVALIDDATA;

            avio_skip(s->pb, 4);

            size -= 16;

            ret = av_get_packet(s->pb, pkt, size);

            pkt->pos = pos;

            pkt->stream_index = 0;

            pkt->duration = size / st->codecpar->ch_layout.nb_channels;

            return ret;

        default:

            av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);

            break;

        }

        avio_skip(s->pb, size);

    }

    return AVERROR_EOF;

}

const FFInputFormat ff_threedostr_demuxer = {

    .p.name         = "3dostr",

    .p.long_name    = NULL_IF_CONFIG_SMALL("3DO STR"),

    .p.extensions   = "str",

    .p.flags        = AVFMT_GENERIC_INDEX,

    .read_probe     = threedostr_probe,

    .read_header    = threedostr_read_header,

    .read_packet    = threedostr_read_packet,

};