/*

 * WavArc demuxer

 * Copyright (c) 2023 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 "avio_internal.h"

#include "demux.h"

#include "internal.h"

typedef struct WavArcContext {

    int64_t data_end;

} WavArcContext;

static int wavarc_probe(const AVProbeData *p)

{

    int len = p->buf[0];

    uint32_t id;

    if (len == 0 || len + 6 >= p->buf_size)

        return 0;

    if (p->buf[len + 1] != 0)

        return 0;

    id = AV_RL32(p->buf + len + 2);

    if (id != MKTAG('0','C','P','Y') &&

        id != MKTAG('1','D','I','F') &&

        id != MKTAG('2','S','L','P') &&

        id != MKTAG('3','N','L','P') &&

        id != MKTAG('4','A','L','P') &&

        id != MKTAG('5','E','L','P'))

        return 0;

    return AVPROBE_SCORE_MAX / 3 * 2;

}

static int wavarc_read_header(AVFormatContext *s)

{

    WavArcContext *w = s->priv_data;

    AVIOContext *pb = s->pb;

    AVCodecParameters *par;

    int filename_len, fmt_len, ret;

    uint8_t data[36];

    AVStream *st;

    uint32_t id;

    filename_len = avio_r8(pb);

    if (filename_len == 0)

        return AVERROR_INVALIDDATA;

    avio_skip(pb, filename_len);

    if (avio_r8(pb))

        return AVERROR_INVALIDDATA;

    id = avio_rl32(pb);

    w->data_end = avio_tell(pb);

    if ((ret = ffio_read_size(pb, data, sizeof(data))) < 0)

        return ret;

    w->data_end += 16LL + AV_RL32(data + 4);

    fmt_len = AV_RL32(data + 32);

    if (fmt_len < 12)

        return AVERROR_INVALIDDATA;

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    par = st->codecpar;

    ret = ff_alloc_extradata(par, fmt_len + sizeof(data));

    if (ret < 0)

        return ret;

    memcpy(par->extradata, data, sizeof(data));

    ret = ffio_read_size(pb, par->extradata + sizeof(data), fmt_len);

    if (ret < 0)

        return ret;

    par->codec_type = AVMEDIA_TYPE_AUDIO;

    par->codec_id   = AV_CODEC_ID_WAVARC;

    par->codec_tag  = id;

    do {

        id = avio_rl32(pb);

        if (id != MKTAG('d','a','t','a'))

            avio_skip(pb, avio_rl32(pb));

    } while (id != MKTAG('d','a','t','a') && !avio_feof(pb));

    avio_skip(pb, 4);

    if (AV_RL32(par->extradata + 16) != MKTAG('R','I','F','F'))

        return AVERROR_INVALIDDATA;

    if (AV_RL32(par->extradata + 24) != MKTAG('W','A','V','E'))

        return AVERROR_INVALIDDATA;

    if (AV_RL32(par->extradata + 28) != MKTAG('f','m','t',' '))

        return AVERROR_INVALIDDATA;

    av_channel_layout_default(&par->ch_layout, AV_RL16(par->extradata + 38));

    par->sample_rate = AV_RL32(par->extradata + 40);

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

    st->start_time = 0;

    return 0;

}

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

{

    WavArcContext *w = s->priv_data;

    AVIOContext *pb = s->pb;

    int64_t size, left = w->data_end - avio_tell(pb);

    int ret;

    size = FFMIN(left, 1024);

    if (size <= 0)

        return AVERROR_EOF;

    ret = av_get_packet(pb, pkt, size);

    pkt->stream_index = 0;

    return ret;

}

const FFInputFormat ff_wavarc_demuxer = {

    .p.name         = "wavarc",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Waveform Archiver"),

    .p.flags        = AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK | AVFMT_NOTIMESTAMPS,

    .p.extensions   = "wa",

    .priv_data_size = sizeof(WavArcContext),

    .read_probe     = wavarc_probe,

    .read_packet    = wavarc_read_packet,

    .read_header    = wavarc_read_header,

    .raw_codec_id   = AV_CODEC_ID_WAVARC,

};