/*
  * 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/intreadwrite.h"
 #include "avformat.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 uint64_t dsf_channel_layout[] = {
     0,
     AV_CH_LAYOUT_MONO,
     AV_CH_LAYOUT_STEREO,
     AV_CH_LAYOUT_SURROUND,
     AV_CH_LAYOUT_QUAD,
     AV_CH_LAYOUT_4POINT0,
     AV_CH_LAYOUT_5POINT0_BACK,
     AV_CH_LAYOUT_5POINT1_BACK,
 };
 
 static void read_id3(AVFormatContext *s, uint64_t id3pos)
 {
     ID3v2ExtraMeta *id3v2_extra_meta = NULL;
     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;
 
     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->channel_layout = dsf_channel_layout[channel_type];
     if (!st->codecpar->channel_layout)

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

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

     if (st->codecpar->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->channels;

     st->codecpar->block_align = avio_rl32(pb);
     if (st->codecpar->block_align > INT_MAX / st->codecpar->channels) {

         avpriv_request_sample(s, "block_align overflow");
         return AVERROR_INVALIDDATA;
     }

     st->codecpar->block_align *= st->codecpar->channels;

     st->codecpar->bit_rate = st->codecpar->channels * st->codecpar->sample_rate * 8LL;

     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;

     s->internal->data_offset = avio_tell(pb);

 
     return 0;
 }
 
 static int dsf_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     DSFContext *dsf = s->priv_data;
     AVIOContext *pb = s->pb;
     AVStream *st = s->streams[0];
     int64_t pos = avio_tell(pb);

     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 - s->internal->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->channels; ch++) {
                 ret = avio_read(pb, dst,  packet_size / st->codecpar->channels);
                 if (ret < packet_size / st->codecpar->channels)
                     return AVERROR_EOF;
 
                 dst += ret;
                 avio_skip(pb, skip_size / st->codecpar->channels);
             }
 

             pkt->pos = pos;
             pkt->stream_index = 0;
             pkt->pts = (pos - s->internal->data_offset) / st->codecpar->channels;
             pkt->duration = packet_size / st->codecpar->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 - s->internal->data_offset) / st->codecpar->channels;
     pkt->duration = st->codecpar->block_align / st->codecpar->channels;
 
     return 0;

 }
 
 AVInputFormat ff_dsf_demuxer = {
     .name           = "dsf",
     .long_name      = NULL_IF_CONFIG_SMALL("DSD Stream File (DSF)"),
     .priv_data_size = sizeof(DSFContext),
     .read_probe     = dsf_probe,
     .read_header    = dsf_read_header,
     .read_packet    = dsf_read_packet,
     .flags          = AVFMT_GENERIC_INDEX | AVFMT_NO_BYTE_SEEK,
 };