/*

 * AIX demuxer

 * Copyright (c) 2016 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 aix_probe(const AVProbeData *p)

{

    if (AV_RL32(p->buf) != MKTAG('A','I','X','F') ||

        AV_RB32(p->buf +  8) != 0x01000014 ||

        AV_RB32(p->buf + 12) != 0x00000800)

        return 0;

    return AVPROBE_SCORE_MAX;

}

static int aix_read_header(AVFormatContext *s)

{

    unsigned nb_streams, first_offset, nb_segments;

    unsigned stream_list_offset;

    unsigned segment_list_offset = 0x20;

    unsigned segment_list_entry_size = 0x10;

    unsigned size;

    int i;

    avio_skip(s->pb, 4);

    first_offset = avio_rb32(s->pb) + 8;

    avio_skip(s->pb, 16);

    nb_segments = avio_rb16(s->pb);

    if (nb_segments == 0)

        return AVERROR_INVALIDDATA;

    stream_list_offset = segment_list_offset + segment_list_entry_size * nb_segments + 0x10;

    if (stream_list_offset >= first_offset)

        return AVERROR_INVALIDDATA;

    avio_seek(s->pb, stream_list_offset, SEEK_SET);

    nb_streams = avio_r8(s->pb);

    if (nb_streams == 0)

        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, 7);

    for (i = 0; i < nb_streams; i++) {

        AVStream *st = avformat_new_stream(s, NULL);

        if (!st)

            return AVERROR(ENOMEM);

        st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;

        st->codecpar->codec_id    = AV_CODEC_ID_ADPCM_ADX;

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

        st->codecpar->ch_layout.nb_channels = avio_r8(s->pb);

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

        avio_skip(s->pb, 3);

    }

    avio_seek(s->pb, first_offset, SEEK_SET);

    for (i = 0; i < nb_streams; i++) {

        if (avio_rl32(s->pb) != MKTAG('A','I','X','P'))

            return AVERROR_INVALIDDATA;

        size = avio_rb32(s->pb);

        if (size <= 8)

            return AVERROR_INVALIDDATA;

        avio_skip(s->pb, 8);

        ff_get_extradata(s, s->streams[i]->codecpar, s->pb, size - 8);

    }

    return 0;

}

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

{

    unsigned size, index, duration, chunk;

    int64_t pos;

    int sequence, ret, i;

    pos = avio_tell(s->pb);

    if (avio_feof(s->pb))

        return AVERROR_EOF;

    chunk = avio_rl32(s->pb);

    size = avio_rb32(s->pb);

    if (chunk == MKTAG('A','I','X','E')) {

        avio_skip(s->pb, size);

        for (i = 0; i < s->nb_streams; i++) {

            if (avio_feof(s->pb))

                return AVERROR_EOF;

            chunk = avio_rl32(s->pb);

            size = avio_rb32(s->pb);

            avio_skip(s->pb, size);

        }

        pos = avio_tell(s->pb);

        chunk = avio_rl32(s->pb);

        size = avio_rb32(s->pb);

    }

    if (chunk != MKTAG('A','I','X','P'))

        return AVERROR_INVALIDDATA;

    if (size <= 8)

        return AVERROR_INVALIDDATA;

    index = avio_r8(s->pb);

    if (avio_r8(s->pb) != s->nb_streams || index >= s->nb_streams)

        return AVERROR_INVALIDDATA;

    duration = avio_rb16(s->pb);

    sequence = avio_rb32(s->pb);

    if (sequence < 0) {

        avio_skip(s->pb, size - 8);

        return 0;

    }

    ret = av_get_packet(s->pb, pkt, size - 8);

    pkt->stream_index = index;

    pkt->duration = duration;

    pkt->pos = pos;

    return ret;

}

const FFInputFormat ff_aix_demuxer = {

    .p.name      = "aix",

    .p.long_name = NULL_IF_CONFIG_SMALL("CRI AIX"),

    .p.extensions= "aix",

    .p.flags     = AVFMT_GENERIC_INDEX,

    .read_probe  = aix_probe,

    .read_header = aix_read_header,

    .read_packet = aix_read_packet,

};