/*

 * DSD Stream File (DSF) 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 "avformat.h"

#include "demux.h"

#include "internal.h"

#include "id3v2.h"

typedef struct {

    uint64_t data_end;

    uint64_t audio_size;

    uint64_t data_size;

} DSFContext;

static int dsf_probe(const AVProbeData *p)

{

    if (p->buf_size < 12 || memcmp(p->buf, "DSD ", 4) || AV_RL64(p->buf + 4) != 28)

        return 0;

    return AVPROBE_SCORE_MAX;

}

static const AVChannelLayout dsf_channel_layout[] = {

    { .order = AV_CHANNEL_ORDER_UNSPEC },

    AV_CHANNEL_LAYOUT_MONO,

    AV_CHANNEL_LAYOUT_STEREO,

    AV_CHANNEL_LAYOUT_SURROUND,

    AV_CHANNEL_LAYOUT_QUAD,

    AV_CHANNEL_LAYOUT_4POINT0,

    AV_CHANNEL_LAYOUT_5POINT0_BACK,

    AV_CHANNEL_LAYOUT_5POINT1_BACK,

};

static void read_id3(AVFormatContext *s, uint64_t id3pos)

{

    ID3v2ExtraMeta *id3v2_extra_meta;

    if (avio_seek(s->pb, id3pos, SEEK_SET) < 0)

        return;

    ff_id3v2_read(s, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta, 0);

    if (id3v2_extra_meta) {

        ff_id3v2_parse_apic(s, id3v2_extra_meta);

        ff_id3v2_parse_chapters(s, id3v2_extra_meta);

    }

    ff_id3v2_free_extra_meta(&id3v2_extra_meta);

}

static int dsf_read_header(AVFormatContext *s)

{

    DSFContext *dsf = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st;

    uint64_t id3pos;

    unsigned int channel_type;

    int channels;

    avio_skip(pb, 4);

    if (avio_rl64(pb) != 28)

        return AVERROR_INVALIDDATA;

    /* create primary stream before any id3 coverart streams */

    st = avformat_new_stream(s, NULL);

    if (!st)

        return AVERROR(ENOMEM);

    avio_skip(pb, 8);

    id3pos = avio_rl64(pb);

    if (pb->seekable & AVIO_SEEKABLE_NORMAL) {

        read_id3(s, id3pos);

        avio_seek(pb, 28, SEEK_SET);

    }

    /* fmt chunk */

    if (avio_rl32(pb) != MKTAG('f', 'm', 't', ' ') || avio_rl64(pb) != 52)

        return AVERROR_INVALIDDATA;

    if (avio_rl32(pb) != 1) {

        avpriv_request_sample(s, "unknown format version");

        return AVERROR_INVALIDDATA;

    }

    if (avio_rl32(pb)) {

        avpriv_request_sample(s, "unknown format id");

        return AVERROR_INVALIDDATA;

    }

    channel_type = avio_rl32(pb);

    if (channel_type < FF_ARRAY_ELEMS(dsf_channel_layout))

        st->codecpar->ch_layout = dsf_channel_layout[channel_type];

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

        avpriv_request_sample(s, "channel type %i", channel_type);

    st->codecpar->codec_type   = AVMEDIA_TYPE_AUDIO;

    channels = avio_rl32(pb);

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

        st->codecpar->ch_layout.nb_channels = channels;

    } else if (channels != st->codecpar->ch_layout.nb_channels) {

        av_log(s, AV_LOG_ERROR, "Channel count mismatch\n");

        return AVERROR(EINVAL);

    }

    st->codecpar->sample_rate  = avio_rl32(pb) / 8;

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

        return AVERROR_INVALIDDATA;

    switch(avio_rl32(pb)) {

    case 1: st->codecpar->codec_id = AV_CODEC_ID_DSD_LSBF_PLANAR; break;

    case 8: st->codecpar->codec_id = AV_CODEC_ID_DSD_MSBF_PLANAR; break;

    default:

        avpriv_request_sample(s, "unknown most significant bit");

        return AVERROR_INVALIDDATA;

    }

    dsf->audio_size = avio_rl64(pb) / 8 * st->codecpar->ch_layout.nb_channels;

    st->codecpar->block_align = avio_rl32(pb);

    if (st->codecpar->block_align > INT_MAX / st->codecpar->ch_layout.nb_channels ||

        st->codecpar->block_align <= 0) {

        avpriv_request_sample(s, "block_align invalid");

        return AVERROR_INVALIDDATA;

    }

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

    st->codecpar->bit_rate = st->codecpar->ch_layout.nb_channels * 8LL * st->codecpar->sample_rate;

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

    avio_skip(pb, 4);

    /* data chunk */

    dsf->data_end = avio_tell(pb);

    if (avio_rl32(pb) != MKTAG('d', 'a', 't', 'a'))

        return AVERROR_INVALIDDATA;

    dsf->data_size = avio_rl64(pb) - 12;

    dsf->data_end += dsf->data_size + 12;

    return 0;

}

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

{

    FFFormatContext *const si = ffformatcontext(s);

    DSFContext *dsf = s->priv_data;

    AVIOContext *pb = s->pb;

    AVStream *st = s->streams[0];

    int64_t pos = avio_tell(pb);

    int channels = st->codecpar->ch_layout.nb_channels;

    int ret;

    if (pos >= dsf->data_end)

        return AVERROR_EOF;

    if (dsf->data_size > dsf->audio_size) {

        int last_packet = pos == (dsf->data_end - st->codecpar->block_align);

        if (last_packet) {

            int64_t data_pos = pos - si->data_offset;

            int64_t packet_size = dsf->audio_size - data_pos;

            int64_t skip_size = dsf->data_size - data_pos - packet_size;

            uint8_t *dst;

            int ch, ret;

            if (packet_size <= 0 || skip_size <= 0)

                return AVERROR_INVALIDDATA;

            if ((ret = av_new_packet(pkt, packet_size)) < 0)

                return ret;

            dst = pkt->data;

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

                ret = avio_read(pb, dst,  packet_size / st->codecpar->ch_layout.nb_channels);

                if (ret < packet_size / st->codecpar->ch_layout.nb_channels)

                    return AVERROR_EOF;

                dst += ret;

                avio_skip(pb, skip_size / st->codecpar->ch_layout.nb_channels);

            }

            pkt->pos = pos;

            pkt->stream_index = 0;

            pkt->pts = (pos - si->data_offset) / channels;

            pkt->duration = packet_size / channels;

            return 0;

        }

    }

    ret = av_get_packet(pb, pkt, FFMIN(dsf->data_end - pos, st->codecpar->block_align));

    if (ret < 0)

        return ret;

    pkt->stream_index = 0;

    pkt->pts = (pos - si->data_offset) / channels;

    pkt->duration = st->codecpar->block_align / channels;

    return 0;

}

const FFInputFormat ff_dsf_demuxer = {

    .p.name         = "dsf",

    .p.long_name    = NULL_IF_CONFIG_SMALL("DSD Stream File (DSF)"),

    .p.flags        = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK,

    .priv_data_size = sizeof(DSFContext),

    .read_probe     = dsf_probe,

    .read_header    = dsf_read_header,

    .read_packet    = dsf_read_packet,

};