/*
  * AVR 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 "avformat.h"
 #include "internal.h"

 #include "pcm.h"

 
 static int avr_probe(AVProbeData *p)
 {

     if (AV_RL32(p->buf) != MKTAG('2', 'B', 'I', 'T'))
         return 0;
 
     if (!AV_RB16(p->buf+12) || AV_RB16(p->buf+12) > 256) // channels
         return AVPROBE_SCORE_EXTENSION/2;
     if (AV_RB16(p->buf+14) > 256) // bps
         return AVPROBE_SCORE_EXTENSION/2;
 
     return AVPROBE_SCORE_EXTENSION;

 }
 
 static int avr_read_header(AVFormatContext *s)
 {
     uint16_t chan, sign, bps;
     AVStream *st;
 
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
 
     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
 
     avio_skip(s->pb, 4); // magic
     avio_skip(s->pb, 8); // sample_name
 
     chan = avio_rb16(s->pb);
     if (!chan) {
         st->codec->channels = 1;
     } else if (chan == 0xFFFFu) {
         st->codec->channels = 2;
     } else {

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

         return AVERROR_PATCHWELCOME;
     }
 
     st->codec->bits_per_coded_sample = bps = avio_rb16(s->pb);
 
     sign = avio_rb16(s->pb);
 
     avio_skip(s->pb, 2); // loop
     avio_skip(s->pb, 2); // midi

     avio_skip(s->pb, 1); // replay speed

     st->codec->sample_rate = avio_rb24(s->pb);

     avio_skip(s->pb, 4 * 3);
     avio_skip(s->pb, 2 * 3);
     avio_skip(s->pb, 20);
     avio_skip(s->pb, 64);
 

     st->codec->codec_id = ff_get_pcm_codec_id(bps, 0, 1, sign);
     if (st->codec->codec_id == AV_CODEC_ID_NONE) {
         avpriv_request_sample(s, "Bps %d and sign %d", bps, sign);

         return AVERROR_PATCHWELCOME;
     }
 

     st->codec->block_align = bps * st->codec->channels / 8;
 

     avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
     return 0;
 }
 
 AVInputFormat ff_avr_demuxer = {
     .name           = "avr",

     .long_name      = NULL_IF_CONFIG_SMALL("AVR (Audio Visual Research)"),

     .read_probe     = avr_probe,
     .read_header    = avr_read_header,

     .read_packet    = ff_pcm_read_packet,

     .read_seek      = ff_pcm_read_seek,

     .extensions     = "avr",

     .flags          = AVFMT_GENERIC_INDEX,

 };