/*

 * Wideband Single-bit Data (WSD) demuxer

 * Copyright (c) 2014 Peter Ross

 *

 * 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 "libavutil/mem.h"

#include "libavutil/timecode.h"

#include "avformat.h"

#include "demux.h"

#include "rawdec.h"

static int wsd_probe(const AVProbeData *p)

{

    if (p->buf_size < 45 || memcmp(p->buf, "1bit", 4) ||

        !AV_RB32(p->buf + 36) || !p->buf[44] ||

        (p->buf[0] >= 0x10 && (AV_RB32(p->buf + 20) < 0x80 || AV_RB32(p->buf + 24) < 0x80)))

       return 0;

    return AVPROBE_SCORE_MAX;

}

static int empty_string(const char *buf, unsigned size)

{

    while (size--) {

       if (*buf++ != ' ')

           return 0;

    }

    return 1;

}

static int wsd_to_av_channel_layoyt(AVFormatContext *s, int bit)

{

    switch (bit) {

    case 2: return AV_CH_BACK_RIGHT;

    case 3:

        avpriv_request_sample(s, "Rr-middle");

        break;

    case 4: return AV_CH_BACK_CENTER;

    case 5:

        avpriv_request_sample(s, "Lr-middle");

        break;

    case 6: return AV_CH_BACK_LEFT;

    case 24: return AV_CH_LOW_FREQUENCY;

    case 26: return AV_CH_FRONT_RIGHT;

    case 27: return AV_CH_FRONT_RIGHT_OF_CENTER;

    case 28: return AV_CH_FRONT_CENTER;

    case 29: return AV_CH_FRONT_LEFT_OF_CENTER;

    case 30: return AV_CH_FRONT_LEFT;

    default:

        av_log(s, AV_LOG_WARNING, "reserved channel assignment\n");

        break;

    }

    return 0;

}

static int get_metadata(AVFormatContext *s, const char *const tag, const unsigned size)

{

    uint8_t *buf;

    if (!(size + 1))

        return AVERROR(ENOMEM);

    buf = av_malloc(size + 1);

    if (!buf)

        return AVERROR(ENOMEM);

    if (avio_read(s->pb, buf, size) != size) {

        av_free(buf);

        return AVERROR(EIO);

    }

    if (empty_string(buf, size)) {

        av_free(buf);

        return 0;

    }

    buf[size] = 0;

    av_dict_set(&s->metadata, tag, buf, AV_DICT_DONT_STRDUP_VAL);

    return 0;

}

static int wsd_read_header(AVFormatContext *s)

{

    AVIOContext *pb = s->pb;

    AVStream *st;

    int version;

    uint32_t text_offset, data_offset, channel_assign;

    char playback_time[AV_TIMECODE_STR_SIZE];

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    avio_skip(pb, 8);

    version = avio_r8(pb);

    av_log(s, AV_LOG_DEBUG, "version: %i.%i\n", version >> 4, version & 0xF);

    avio_skip(pb, 11);

    if (version < 0x10) {

        text_offset = 0x80;

        data_offset = 0x800;

        avio_skip(pb, 8);

    } else {

        text_offset = avio_rb32(pb);

        data_offset = avio_rb32(pb);

    }

    avio_skip(pb, 4);

    av_timecode_make_smpte_tc_string2(playback_time, (AVRational){1,1}, avio_rb32(pb) & 0x00ffffffU, 1, 1);

    av_dict_set(&s->metadata, "playback_time", playback_time, 0);

    st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;

    st->codecpar->codec_id    = AV_CODEC_ID_DSD_MSBF;

    st->codecpar->sample_rate = avio_rb32(pb) / 8;

    avio_skip(pb, 4);

    st->codecpar->ch_layout.nb_channels = avio_r8(pb) & 0xF;

    st->codecpar->bit_rate    = (int64_t)st->codecpar->ch_layout.nb_channels *

                                st->codecpar->sample_rate * 8LL;

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

        return AVERROR_INVALIDDATA;

    avio_skip(pb, 3);

    channel_assign         = avio_rb32(pb);

    if (!(channel_assign & 1)) {

        uint64_t ch_mask = 0;

        int i;

        for (i = 1; i < 32; i++)

            if ((channel_assign >> i) & 1)

                ch_mask |= wsd_to_av_channel_layoyt(s, i);

        av_channel_layout_from_mask(&st->codecpar->ch_layout, ch_mask);

    }

    avio_skip(pb, 16);

    if (avio_rb32(pb))

       avpriv_request_sample(s, "emphasis");

    if (avio_seek(pb, text_offset, SEEK_SET) >= 0) {

        get_metadata(s, "title",       128);

        get_metadata(s, "composer",    128);

        get_metadata(s, "song_writer", 128);

        get_metadata(s, "artist",      128);

        get_metadata(s, "album",       128);

        get_metadata(s, "genre",        32);

        get_metadata(s, "date",         32);

        get_metadata(s, "location",     32);

        get_metadata(s, "comment",     512);

        get_metadata(s, "user",        512);

    }

    return avio_seek(pb, data_offset, SEEK_SET);

}

const FFInputFormat ff_wsd_demuxer = {

    .p.name         = "wsd",

    .p.long_name    = NULL_IF_CONFIG_SMALL("Wideband Single-bit Data (WSD)"),

    .p.extensions   = "wsd",

    .p.flags        = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK,

    .p.priv_class   = &ff_raw_demuxer_class,

    .read_probe   = wsd_probe,

    .read_header  = wsd_read_header,

    .read_packet  = ff_raw_read_partial_packet,

    .raw_codec_id = AV_CODEC_ID_DSD_MSBF,

    .priv_data_size = sizeof(FFRawDemuxerContext),

};