/*

 * GENH 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 "libavutil/intreadwrite.h"

#include "avformat.h"

#include "demux.h"

#include "internal.h"

typedef struct GENHDemuxContext {

    unsigned dsp_int_type;

    unsigned interleave_size;

} GENHDemuxContext;

static int genh_probe(const AVProbeData *p)

{

    if (AV_RL32(p->buf) != MKTAG('G','E','N','H'))

        return 0;

    if (AV_RL32(p->buf+4) <= 0 || AV_RL32(p->buf+4) > 0xFFFF) // channels

        return 0;

    return AVPROBE_SCORE_MAX / 3 * 2;

}

static int genh_read_header(AVFormatContext *s)

{

    unsigned start_offset, header_size, codec, coef_type, coef[2];

    GENHDemuxContext *c = s->priv_data;

    av_unused unsigned coef_splitted[2];

    int align, ch, ret;

    AVStream *st;

    avio_skip(s->pb, 4);

    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);

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

        return AVERROR_INVALIDDATA;

    if (st->codecpar->ch_layout.nb_channels == 1)

        st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;

    else if (st->codecpar->ch_layout.nb_channels == 2)

        st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;

    align                  =

    c->interleave_size     = avio_rl32(s->pb);

    if (align < 0 || align > INT_MAX / st->codecpar->ch_layout.nb_channels)

        return AVERROR_INVALIDDATA;

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

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

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

        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, 4);

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

    codec = avio_rl32(s->pb);

    switch (codec) {

    case  0: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_PSX;        break;

    case  1:

    case 11: st->codecpar->bits_per_coded_sample = 4;

             if (st->codecpar->ch_layout.nb_channels > INT_MAX / 36)

                return AVERROR_INVALIDDATA;

             st->codecpar->block_align = 36 * st->codecpar->ch_layout.nb_channels;

             st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_WAV;    break;

    case  2: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_DTK;        break;

    case  3: st->codecpar->codec_id = st->codecpar->block_align > 0 ?

                                   AV_CODEC_ID_PCM_S16BE_PLANAR :

                                   AV_CODEC_ID_PCM_S16BE;        break;

    case  4: st->codecpar->codec_id = st->codecpar->block_align > 0 ?

                                   AV_CODEC_ID_PCM_S16LE_PLANAR :

                                   AV_CODEC_ID_PCM_S16LE;        break;

    case  5: st->codecpar->codec_id = st->codecpar->block_align > 0 ?

                                   AV_CODEC_ID_PCM_S8_PLANAR :

                                   AV_CODEC_ID_PCM_S8;           break;

    case  6: if (st->codecpar->block_align > INT_MAX/1024)

                 return AVERROR_INVALIDDATA;

             st->codecpar->codec_id = AV_CODEC_ID_SDX2_DPCM;        break;

    case  7: ret = ff_alloc_extradata(st->codecpar, 2);

             if (ret < 0)

                 return ret;

             AV_WL16(st->codecpar->extradata, 3);

             st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_WS;     break;

    case 10: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_AICA;       break;

    case 12: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_THP;        break;

    case 13: st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;           break;

    case 17: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_QT;     break;

    default:

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

             return AVERROR_PATCHWELCOME;

    }

    start_offset = avio_rl32(s->pb);

    header_size  = avio_rl32(s->pb);

    if (header_size > start_offset)

        return AVERROR_INVALIDDATA;

    if (header_size == 0)

        start_offset = 0x800;

    coef[0]          = avio_rl32(s->pb);

    coef[1]          = avio_rl32(s->pb);

    c->dsp_int_type  = avio_rl32(s->pb);

    coef_type        = avio_rl32(s->pb);

    coef_splitted[0] = avio_rl32(s->pb);

    coef_splitted[1] = avio_rl32(s->pb);

    if (st->codecpar->codec_id == AV_CODEC_ID_ADPCM_THP) {

        if (st->codecpar->ch_layout.nb_channels > 2) {

            avpriv_request_sample(s, "channels %d>2", st->codecpar->ch_layout.nb_channels);

            return AVERROR_PATCHWELCOME;

        }

        ff_alloc_extradata(st->codecpar, 32 * st->codecpar->ch_layout.nb_channels);

        for (ch = 0; ch < st->codecpar->ch_layout.nb_channels; ch++) {

            if (coef_type & 1) {

                avpriv_request_sample(s, "coef_type & 1");

                return AVERROR_PATCHWELCOME;

            } else {

                avio_seek(s->pb, coef[ch], SEEK_SET);

                avio_read(s->pb, st->codecpar->extradata + 32 * ch, 32);

            }

        }

        if (c->dsp_int_type == 1) {

            st->codecpar->block_align = 8 * st->codecpar->ch_layout.nb_channels;

            if (c->interleave_size != 1 &&

                c->interleave_size != 2 &&

                c->interleave_size != 4)

                return AVERROR_INVALIDDATA;

        }

    }

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

        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, start_offset - avio_tell(s->pb));

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

    return 0;

}

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

{

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

    GENHDemuxContext *c = s->priv_data;

    int ret;

    if (c->dsp_int_type == 1 && par->codec_id == AV_CODEC_ID_ADPCM_THP &&

        par->ch_layout.nb_channels > 1) {

        int i, ch;

        if (avio_feof(s->pb))

            return AVERROR_EOF;

        ret = av_new_packet(pkt, 8 * par->ch_layout.nb_channels);

        if (ret < 0)

            return ret;

        for (i = 0; i < 8 / c->interleave_size; i++) {

            for (ch = 0; ch < par->ch_layout.nb_channels; ch++) {

                pkt->data[ch * 8 + i*c->interleave_size+0] = avio_r8(s->pb);

                pkt->data[ch * 8 + i*c->interleave_size+1] = avio_r8(s->pb);

            }

        }

        ret = 0;

    } else if (par->codec_id == AV_CODEC_ID_SDX2_DPCM) {

        ret = av_get_packet(s->pb, pkt, par->block_align * 1024);

    } else {

        ret = av_get_packet(s->pb, pkt, par->block_align ? par->block_align :

                                                           1024 * par->ch_layout.nb_channels);

    }

    pkt->stream_index = 0;

    return ret;

}

const FFInputFormat ff_genh_demuxer = {

    .p.name         = "genh",

    .p.long_name    = NULL_IF_CONFIG_SMALL("GENeric Header"),

    .p.extensions   = "genh",

    .priv_data_size = sizeof(GENHDemuxContext),

    .read_probe     = genh_probe,

    .read_header    = genh_read_header,

    .read_packet    = genh_read_packet,

};