/*

 * BRSTM demuxer

 * Copyright (c) 2012 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 "libavutil/mem.h"

#include "libavcodec/bytestream.h"

#include "avformat.h"

#include "avio_internal.h"

#include "demux.h"

#include "internal.h"

typedef struct BRSTMCoeffOffset {

    uint8_t  channel;

    uint32_t offset;

} BRSTMCoeffOffset;

typedef struct BRSTMDemuxContext {

    uint32_t    block_size;

    uint32_t    block_count;

    uint32_t    current_block;

    uint32_t    samples_per_block;

    uint32_t    last_block_used_bytes;

    uint32_t    last_block_size;

    uint32_t    last_block_samples;

    uint32_t    data_start;

    uint8_t     table[256 * 32];

    uint8_t     *adpc;

    BRSTMCoeffOffset offsets[256];

    int         little_endian;

} BRSTMDemuxContext;

static int probe(const AVProbeData *p)

{

    if (AV_RL32(p->buf) == MKTAG('R','S','T','M') &&

        (AV_RL16(p->buf + 4) == 0xFFFE ||

         AV_RL16(p->buf + 4) == 0xFEFF))

        return AVPROBE_SCORE_MAX / 3 * 2;

    return 0;

}

static int probe_bfstm(const AVProbeData *p)

{

    if ((AV_RL32(p->buf) == MKTAG('F','S','T','M') ||

         AV_RL32(p->buf) == MKTAG('C','S','T','M')) &&

        (AV_RL16(p->buf + 4) == 0xFFFE ||

         AV_RL16(p->buf + 4) == 0xFEFF))

        return AVPROBE_SCORE_MAX / 3 * 2;

    return 0;

}

static int read_close(AVFormatContext *s)

{

    BRSTMDemuxContext *b = s->priv_data;

    av_freep(&b->adpc);

    return 0;

}

static int sort_offsets(const void *a, const void *b)

{

    const BRSTMCoeffOffset *s1 = a;

    const BRSTMCoeffOffset *s2 = b;

    return FFDIFFSIGN(s1->offset, s2->offset);

}

static av_always_inline unsigned int read16(AVFormatContext *s)

{

    BRSTMDemuxContext *b = s->priv_data;

    if (b->little_endian)

        return avio_rl16(s->pb);

    else

        return avio_rb16(s->pb);

}

static av_always_inline unsigned int read32(AVFormatContext *s)

{

    BRSTMDemuxContext *b = s->priv_data;

    if (b->little_endian)

        return avio_rl32(s->pb);

    else

        return avio_rb32(s->pb);

}

static int read_header(AVFormatContext *s)

{

    BRSTMDemuxContext *b = s->priv_data;

    int bom, major, minor, codec, chunk;

    int64_t h1offset, pos, toffset;

    uint32_t size, asize, start = 0;

    AVStream *st;

    int loop = 0;

    int bfstm = !strcmp("bfstm", s->iformat->name);

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;

    avio_skip(s->pb, 4);

    bom = avio_rb16(s->pb);

    if (bom != 0xFEFF && bom != 0xFFFE) {

        av_log(s, AV_LOG_ERROR, "invalid byte order: %X\n", bom);

        return AVERROR_INVALIDDATA;

    }

    if (bom == 0xFFFE)

        b->little_endian = 1;

    if (!bfstm) {

        major = avio_r8(s->pb);

        minor = avio_r8(s->pb);

        avio_skip(s->pb, 4); // size of file

        size = read16(s);

        if (size < 14)

            return AVERROR_INVALIDDATA;

        avio_skip(s->pb, size - 14);

        pos = avio_tell(s->pb);

        if (avio_rl32(s->pb) != MKTAG('H','E','A','D'))

            return AVERROR_INVALIDDATA;

    } else {

        uint32_t info_offset = 0;

        uint16_t section_count, header_size, i;

        header_size = read16(s); // 6

        avio_skip(s->pb, 4); // Unknown constant 0x00030000

        avio_skip(s->pb, 4); // size of file

        section_count = read16(s);

        avio_skip(s->pb, 2); // padding

        for (i = 0; avio_tell(s->pb) < header_size

                    && !(start && info_offset)

                    && i < section_count; i++) {

            uint16_t flag = read16(s);

            avio_skip(s->pb, 2);

            switch (flag) {

            case 0x4000:

                info_offset = read32(s);

                /*info_size =*/ read32(s);

                break;

            case 0x4001:

                avio_skip(s->pb, 4); // seek offset

                avio_skip(s->pb, 4); // seek size

                break;

            case 0x4002:

                start = read32(s) + 8;

                avio_skip(s->pb, 4); //data_size = read32(s);

                break;

            case 0x4003:

                avio_skip(s->pb, 4); // REGN offset

                avio_skip(s->pb, 4); // REGN size

                break;

            }

        }

        if (!info_offset || !start)

            return AVERROR_INVALIDDATA;

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

        pos = avio_tell(s->pb);

        if (avio_rl32(s->pb) != MKTAG('I','N','F','O'))

            return AVERROR_INVALIDDATA;

    }

    size = read32(s);

    if (size < 40)

        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, 4); // unknown

    h1offset = read32(s);

    if (h1offset > size)

        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, 12);

    toffset = read32(s) + 16LL;

    if (toffset > size)

        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, pos + h1offset + 8 - avio_tell(s->pb));

    codec = avio_r8(s->pb);

    switch (codec) {

    case 0: codec = AV_CODEC_ID_PCM_S8_PLANAR;    break;

    case 1: codec = b->little_endian ?

                    AV_CODEC_ID_PCM_S16LE_PLANAR :

                    AV_CODEC_ID_PCM_S16BE_PLANAR; break;

    case 2: codec = b->little_endian ?

                    AV_CODEC_ID_ADPCM_THP_LE :

                    AV_CODEC_ID_ADPCM_THP;        break;

    default:

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

        return AVERROR_PATCHWELCOME;

    }

    loop = avio_r8(s->pb); // loop flag

    st->codecpar->codec_id = codec;

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

    if (!st->codecpar->ch_layout.nb_channels)

        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, 1); // padding

    st->codecpar->sample_rate = bfstm ? read32(s) : read16(s);

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

        return AVERROR_INVALIDDATA;

    if (!bfstm)

        avio_skip(s->pb, 2); // padding

    if (loop) {

        if (av_dict_set_int(&s->metadata, "loop_start",

                            av_rescale(read32(s), AV_TIME_BASE,

                                       st->codecpar->sample_rate),

                            0) < 0)

            return AVERROR(ENOMEM);

    } else {

        avio_skip(s->pb, 4);

    }

    st->start_time = 0;

    st->duration = read32(s);

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

    if (!bfstm)

        start = read32(s);

    b->current_block = 0;

    b->block_count = read32(s);

    if (b->block_count > UINT16_MAX) {

        av_log(s, AV_LOG_WARNING, "too many blocks: %"PRIu32"\n", b->block_count);

        return AVERROR_INVALIDDATA;

    }

    b->block_size = read32(s);

    if (b->block_size > UINT32_MAX / st->codecpar->ch_layout.nb_channels)

        return AVERROR_INVALIDDATA;

    b->samples_per_block = read32(s);

    b->last_block_used_bytes = read32(s);

    b->last_block_samples = read32(s);

    b->last_block_size = read32(s);

    if (b->last_block_size > UINT32_MAX / st->codecpar->ch_layout.nb_channels)

        return AVERROR_INVALIDDATA;

    if (b->last_block_used_bytes > b->last_block_size)

        return AVERROR_INVALIDDATA;

    if (codec == AV_CODEC_ID_ADPCM_THP || codec == AV_CODEC_ID_ADPCM_THP_LE) {

        int ch;

        avio_skip(s->pb, pos + toffset - avio_tell(s->pb));

        if (!bfstm)

            toffset = read32(s) + 16LL;

        else

            toffset = toffset + read32(s) + st->codecpar->ch_layout.nb_channels * 8 - 8;

        if (toffset > size)

            return AVERROR_INVALIDDATA;

        if (!bfstm) {

            avio_skip(s->pb, pos + toffset - avio_tell(s->pb) - 8LL * (st->codecpar->ch_layout.nb_channels + 1));

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

                avio_skip(s->pb, 4);

                b->offsets[ch].channel = ch;

                b->offsets[ch].offset = read32(s);

            }

            qsort(b->offsets, st->codecpar->ch_layout.nb_channels, sizeof(*b->offsets), sort_offsets);

        }

        avio_skip(s->pb, pos + toffset - avio_tell(s->pb));

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

            if (!bfstm)

                avio_skip(s->pb, pos + 16LL + b->offsets[ch].offset - avio_tell(s->pb));

            if (avio_read(s->pb, b->table + ch * 32, 32) != 32)

                return AVERROR_INVALIDDATA;

            if (bfstm)

                avio_skip(s->pb, 14);

        }

    }

    if (size < (avio_tell(s->pb) - pos))

        return AVERROR_INVALIDDATA;

    avio_skip(s->pb, size - (avio_tell(s->pb) - pos));

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

        chunk = avio_rl32(s->pb);

        size  = read32(s);

        if (size < 8)

            return AVERROR_INVALIDDATA;

        size -= 8;

        switch (chunk) {

        case MKTAG('S','E','E','K'):

        case MKTAG('A','D','P','C'):

            if (codec != AV_CODEC_ID_ADPCM_THP &&

                codec != AV_CODEC_ID_ADPCM_THP_LE)

                goto skip;

            asize = b->block_count * st->codecpar->ch_layout.nb_channels * 4;

            if (size < asize)

                return AVERROR_INVALIDDATA;

            if (b->adpc) {

                av_log(s, AV_LOG_WARNING, "skipping additional ADPC chunk\n");

                goto skip;

            } else {

                b->adpc = av_mallocz(asize);

                if (!b->adpc)

                    return AVERROR(ENOMEM);

                if (bfstm && codec != AV_CODEC_ID_ADPCM_THP_LE) {

                    // Big-endian BFSTMs have little-endian SEEK tables

                    // for some strange reason.

                    int i;

                    for (i = 0; i < asize; i += 2) {

                        b->adpc[i+1] = avio_r8(s->pb);

                        b->adpc[i]   = avio_r8(s->pb);

                    }

                } else {

                    avio_read(s->pb, b->adpc, asize);

                }

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

            }

            break;

        case MKTAG('D','A','T','A'):

            if ((start < avio_tell(s->pb)) ||

                (!b->adpc && (codec == AV_CODEC_ID_ADPCM_THP ||

                              codec == AV_CODEC_ID_ADPCM_THP_LE)))

                return AVERROR_INVALIDDATA;

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

            if (bfstm && (codec == AV_CODEC_ID_ADPCM_THP ||

                          codec == AV_CODEC_ID_ADPCM_THP_LE))

                avio_skip(s->pb, 24);

            b->data_start = avio_tell(s->pb);

            if (!bfstm && (major != 1 || minor))

                avpriv_request_sample(s, "Version %d.%d", major, minor);

            return 0;

        default:

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

skip:

            avio_skip(s->pb, size);

        }

    }

    return AVERROR_EOF;

}

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

{

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

    BRSTMDemuxContext *b = s->priv_data;

    uint32_t samples, size, skip = 0;

    int channels = par->ch_layout.nb_channels;

    int ret, i;

    if (avio_feof(s->pb))

        return AVERROR_EOF;

    b->current_block++;

    if (b->current_block == b->block_count) {

        size    = b->last_block_used_bytes;

        samples = b->last_block_samples;

        skip    = b->last_block_size - b->last_block_used_bytes;

        if (samples < size * 14 / 8) {

            uint32_t adjusted_size = samples / 14 * 8;

            if (samples % 14)

                adjusted_size += (samples % 14 + 1) / 2 + 1;

            skip += size - adjusted_size;

            size = adjusted_size;

        }

    } else if (b->current_block < b->block_count) {

        size    = b->block_size;

        samples = b->samples_per_block;

    } else {

        return AVERROR_EOF;

    }

    if (par->codec_id == AV_CODEC_ID_ADPCM_THP ||

        par->codec_id == AV_CODEC_ID_ADPCM_THP_LE) {

        uint8_t *dst;

        if (!b->adpc) {

            av_log(s, AV_LOG_ERROR, "adpcm_thp requires ADPC chunk, but none was found.\n");

            return AVERROR_INVALIDDATA;

        }

        if (size > (INT_MAX - 32 - 4) ||

            (32 + 4 + size) > (INT_MAX / channels) ||

            (32 + 4 + size) * channels > INT_MAX - 8)

            return AVERROR_INVALIDDATA;

        if ((ret = av_new_packet(pkt, 8 + (32 + 4 + size) * channels)) < 0)

            return ret;

        dst = pkt->data;

        if (par->codec_id == AV_CODEC_ID_ADPCM_THP_LE) {

            bytestream_put_le32(&dst, size * channels);

            bytestream_put_le32(&dst, samples);

        } else {

            bytestream_put_be32(&dst, size * channels);

            bytestream_put_be32(&dst, samples);

        }

        bytestream_put_buffer(&dst, b->table, 32 * channels);

        bytestream_put_buffer(&dst, b->adpc + 4 * channels *

                                    (b->current_block - 1), 4 * channels);

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

            ret = ffio_read_size(s->pb, dst, size);

            dst += size;

            avio_skip(s->pb, skip);

            if (ret < 0) {

                return ret;

            }

        }

        pkt->duration = samples;

    } else {

        size *= channels;

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

    }

    pkt->stream_index = 0;

    if (ret != size)

        ret = AVERROR_INVALIDDATA;

    return ret;

}

static int read_seek(AVFormatContext *s, int stream_index,

                     int64_t timestamp, int flags)

{

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

    BRSTMDemuxContext *b = s->priv_data;

    int64_t ret = 0;

    if (timestamp < 0)

        timestamp = 0;

    timestamp /= b->samples_per_block;

    if (timestamp >= b->block_count)

        timestamp = b->block_count - 1;

    ret = avio_seek(s->pb, b->data_start + timestamp * b->block_size *

                           st->codecpar->ch_layout.nb_channels, SEEK_SET);

    if (ret < 0)

        return ret;

    b->current_block = timestamp;

    avpriv_update_cur_dts(s, st, timestamp * b->samples_per_block);

    return 0;

}

const FFInputFormat ff_brstm_demuxer = {

    .p.name         = "brstm",

    .p.long_name    = NULL_IF_CONFIG_SMALL("BRSTM (Binary Revolution Stream)"),

    .p.extensions   = "brstm",

    .priv_data_size = sizeof(BRSTMDemuxContext),

    .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,

    .read_probe     = probe,

    .read_header    = read_header,

    .read_packet    = read_packet,

    .read_close     = read_close,

    .read_seek      = read_seek,

};

const FFInputFormat ff_bfstm_demuxer = {

    .p.name         = "bfstm",

    .p.long_name    = NULL_IF_CONFIG_SMALL("BFSTM (Binary Cafe Stream)"),

    .p.extensions   = "bfstm,bcstm",

    .priv_data_size = sizeof(BRSTMDemuxContext),

    .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP,

    .read_probe     = probe_bfstm,

    .read_header    = read_header,

    .read_packet    = read_packet,

    .read_close     = read_close,

    .read_seek      = read_seek,

};