/*

 * HCA demuxer

 * Copyright (c) 2020 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/opt.h"

#include "libavutil/intreadwrite.h"

#include "libavcodec/bytestream.h"

#include "avformat.h"

#include "avio_internal.h"

#include "demux.h"

#include "internal.h"

#define HCA_MASK 0x7f7f7f7f

typedef struct HCADemuxContext {

    AVClass *class;

    int64_t keyl;

    int64_t keyh;

    int subkey;

} HCADemuxContext;

static int hca_probe(const AVProbeData *p)

{

    if ((AV_RL32(p->buf) & HCA_MASK) != MKTAG('H', 'C', 'A', 0))

        return 0;

    if ((AV_RL32(p->buf + 8) & HCA_MASK) != MKTAG('f', 'm', 't', 0))

        return 0;

    return AVPROBE_SCORE_MAX / 3;

}

static int hca_read_header(AVFormatContext *s)

{

    HCADemuxContext *hca = s->priv_data;

    AVCodecParameters *par;

    GetByteContext gb;

    AVIOContext *pb = s->pb;

    AVStream *st;

    uint32_t chunk;

    uint16_t version;

    uint32_t block_count;

    uint16_t block_size, data_offset;

    int ret;

    avio_skip(pb, 4);

    version = avio_rb16(pb);

    data_offset = avio_rb16(pb);

    if (data_offset <= 8)

        return AVERROR_INVALIDDATA;

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    par = st->codecpar;

    ret = ff_alloc_extradata(par, data_offset + 10);

    if (ret < 0)

        return ret;

    ret = ffio_read_size(pb, par->extradata + 8, par->extradata_size - 8 - 10);

    if (ret < 0)

        return AVERROR_INVALIDDATA;

    AV_WL32(par->extradata, MKTAG('H', 'C', 'A', 0));

    AV_WB16(par->extradata + 4, version);

    AV_WB16(par->extradata + 6, data_offset);

    AV_WB32(par->extradata + par->extradata_size - 10, hca->keyh);

    AV_WB32(par->extradata + par->extradata_size -  6, hca->keyl);

    AV_WB16(par->extradata + par->extradata_size -  2, hca->subkey);

    bytestream2_init(&gb, par->extradata + 8, par->extradata_size - 8);

    if ((bytestream2_get_le32(&gb) & HCA_MASK) != MKTAG('f', 'm', 't', 0))

        return AVERROR_INVALIDDATA;

    par->codec_type  = AVMEDIA_TYPE_AUDIO;

    par->codec_id    = AV_CODEC_ID_HCA;

    par->codec_tag   = 0;

    st->codecpar->ch_layout.nb_channels = bytestream2_get_byte(&gb);

    par->sample_rate = bytestream2_get_be24(&gb);

    block_count      = bytestream2_get_be32(&gb);

    bytestream2_skip(&gb, 4);

    chunk = bytestream2_get_le32(&gb) & HCA_MASK;

    if (chunk == MKTAG('c', 'o', 'm', 'p')) {

        block_size = bytestream2_get_be16(&gb);

    } else if (chunk == MKTAG('d', 'e', 'c', 0)) {

        block_size = bytestream2_get_be16(&gb);

    } else {

        return AVERROR_INVALIDDATA;

    }

    if (block_size < 8)

        return AVERROR_INVALIDDATA;

    par->block_align = block_size;

    st->duration = 1024 * block_count;

    avio_seek(pb, data_offset, SEEK_SET);

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

    return 0;

}

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

{

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

    int ret;

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

    pkt->duration = 1024;

    return ret;

}

#define OFFSET(x) offsetof(HCADemuxContext, x)

static const AVOption hca_options[] = {

    { "hca_lowkey",

        "Low key used for handling CRI HCA files", OFFSET(keyl),

        AV_OPT_TYPE_INT64, {.i64=0}, .min = 0, .max = UINT32_MAX, .flags = AV_OPT_FLAG_DECODING_PARAM, },

    { "hca_highkey",

        "High key used for handling CRI HCA files", OFFSET(keyh),

        AV_OPT_TYPE_INT64, {.i64=0}, .min = 0, .max = UINT32_MAX, .flags = AV_OPT_FLAG_DECODING_PARAM, },

    { "hca_subkey",

        "Subkey used for handling CRI HCA files", OFFSET(subkey),

        AV_OPT_TYPE_INT, {.i64=0}, .min = 0, .max = UINT16_MAX, .flags = AV_OPT_FLAG_DECODING_PARAM },

    { NULL },

};

static const AVClass hca_class = {

    .class_name = "hca",

    .item_name  = av_default_item_name,

    .option     = hca_options,

    .version    = LIBAVUTIL_VERSION_INT,

};

const FFInputFormat ff_hca_demuxer = {

    .p.name         = "hca",

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

    .p.priv_class   = &hca_class,

    .p.extensions   = "hca",

    .p.flags        = AVFMT_GENERIC_INDEX,

    .priv_data_size = sizeof(HCADemuxContext),

    .read_probe     = hca_probe,

    .read_header    = hca_read_header,

    .read_packet    = hca_read_packet,

};