/*
  * GENH demuxer
  * Copyright (c) 2015 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 "libavcodec/internal.h"

 #include "avformat.h"
 #include "internal.h"
 
 typedef struct GENHDemuxContext {
     unsigned dsp_int_type;
     unsigned interleave_size;
 } GENHDemuxContext;
 
 static int genh_probe(AVProbeData *p)
 {
     if (AV_RL32(p->buf) != MKTAG('G','E','N','H'))
         return 0;

     if (AV_RL32(p->buf+4) <= 0 || AV_RL32(p->buf+4) > 0xFFFF) // channels
         return 0;

 
     return AVPROBE_SCORE_MAX / 3 * 2;
 }
 
 static int genh_read_header(AVFormatContext *s)
 {
     unsigned start_offset, header_size, codec, coef_type, coef[2];
     GENHDemuxContext *c = s->priv_data;

     av_unused unsigned coef_splitted[2];

     int align, ch, ret;

     AVStream *st;
 
     avio_skip(s->pb, 4);
 
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
 

     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
     st->codecpar->channels    = avio_rl32(s->pb);

     if (st->codecpar->channels <= 0 || st->codecpar->channels > FF_SANE_NB_CHANNELS)

         return AVERROR_INVALIDDATA;

     if (st->codecpar->channels == 1)
         st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
     else if (st->codecpar->channels == 2)
         st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;

     align                  =
     c->interleave_size     = avio_rl32(s->pb);

     if (align < 0 || align > INT_MAX / st->codecpar->channels)

         return AVERROR_INVALIDDATA;

     st->codecpar->block_align = align * st->codecpar->channels;
     st->codecpar->sample_rate = avio_rl32(s->pb);

     avio_skip(s->pb, 4);
     st->duration = avio_rl32(s->pb);
 
     codec = avio_rl32(s->pb);
     switch (codec) {

     case  0: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_PSX;        break;

     case  1:

     case 11: st->codecpar->bits_per_coded_sample = 4;
              st->codecpar->block_align = 36 * st->codecpar->channels;
              st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_WAV;    break;
     case  2: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_DTK;        break;
     case  3: st->codecpar->codec_id = st->codecpar->block_align > 0 ?

                                    AV_CODEC_ID_PCM_S16BE_PLANAR :
                                    AV_CODEC_ID_PCM_S16BE;        break;

     case  4: st->codecpar->codec_id = st->codecpar->block_align > 0 ?

                                    AV_CODEC_ID_PCM_S16LE_PLANAR :
                                    AV_CODEC_ID_PCM_S16LE;        break;

     case  5: st->codecpar->codec_id = st->codecpar->block_align > 0 ?

                                    AV_CODEC_ID_PCM_S8_PLANAR :
                                    AV_CODEC_ID_PCM_S8;           break;

     case  6: st->codecpar->codec_id = AV_CODEC_ID_SDX2_DPCM;        break;
     case  7: ret = ff_alloc_extradata(st->codecpar, 2);

              if (ret < 0)
                  return ret;

              AV_WL16(st->codecpar->extradata, 3);
              st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_WS;     break;
     case 10: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_AICA;       break;
     case 12: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_THP;        break;
     case 13: st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;           break;
     case 17: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_QT;     break;

     default:
              avpriv_request_sample(s, "codec %d", codec);
              return AVERROR_PATCHWELCOME;
     }
 
     start_offset = avio_rl32(s->pb);
     header_size  = avio_rl32(s->pb);
 
     if (header_size > start_offset)
         return AVERROR_INVALIDDATA;
 
     if (header_size == 0)
         start_offset = 0x800;
 
     coef[0]          = avio_rl32(s->pb);
     coef[1]          = avio_rl32(s->pb);
     c->dsp_int_type  = avio_rl32(s->pb);
     coef_type        = avio_rl32(s->pb);
     coef_splitted[0] = avio_rl32(s->pb);
     coef_splitted[1] = avio_rl32(s->pb);
 

     if (st->codecpar->codec_id == AV_CODEC_ID_ADPCM_THP) {
         if (st->codecpar->channels > 2) {
             avpriv_request_sample(s, "channels %d>2", st->codecpar->channels);

             return AVERROR_PATCHWELCOME;
         }
 

         ff_alloc_extradata(st->codecpar, 32 * st->codecpar->channels);
         for (ch = 0; ch < st->codecpar->channels; ch++) {

             if (coef_type & 1) {
                 avpriv_request_sample(s, "coef_type & 1");
                 return AVERROR_PATCHWELCOME;
             } else {
                 avio_seek(s->pb, coef[ch], SEEK_SET);

                 avio_read(s->pb, st->codecpar->extradata + 32 * ch, 32);

             }
         }
 
         if (c->dsp_int_type == 1) {

             st->codecpar->block_align = 8 * st->codecpar->channels;

             if (c->interleave_size != 1 &&
                 c->interleave_size != 2 &&
                 c->interleave_size != 4)
                 return AVERROR_INVALIDDATA;
         }
     }
 
     avio_skip(s->pb, start_offset - avio_tell(s->pb));
 

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

 
     return 0;
 }
 
 static int genh_read_packet(AVFormatContext *s, AVPacket *pkt)
 {

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

     GENHDemuxContext *c = s->priv_data;
     int ret;
 

     if (c->dsp_int_type == 1 && par->codec_id == AV_CODEC_ID_ADPCM_THP &&
         par->channels > 1) {

         int i, ch;
 
         if (avio_feof(s->pb))
             return AVERROR_EOF;

         ret = av_new_packet(pkt, 8 * par->channels);

         if (ret < 0)
             return ret;

         for (i = 0; i < 8 / c->interleave_size; i++) {

             for (ch = 0; ch < par->channels; ch++) {

                 pkt->data[ch * 8 + i*c->interleave_size+0] = avio_r8(s->pb);
                 pkt->data[ch * 8 + i*c->interleave_size+1] = avio_r8(s->pb);
             }
         }
         ret = 0;

     } else if (par->codec_id == AV_CODEC_ID_SDX2_DPCM) {
         ret = av_get_packet(s->pb, pkt, par->block_align * 1024);

     } else {

         ret = av_get_packet(s->pb, pkt, par->block_align ? par->block_align : 1024 * par->channels);

     }
 
     pkt->stream_index = 0;
     return ret;
 }
 
 AVInputFormat ff_genh_demuxer = {
     .name           = "genh",
     .long_name      = NULL_IF_CONFIG_SMALL("GENeric Header"),
     .priv_data_size = sizeof(GENHDemuxContext),
     .read_probe     = genh_probe,
     .read_header    = genh_read_header,
     .read_packet    = genh_read_packet,
     .extensions     = "genh",
 };