/*
  * CRYO APC audio format demuxer
  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
  *
  * 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 <string.h>

 #include "avformat.h"
 
 static int apc_probe(AVProbeData *p)
 {
     if (!strncmp(p->buf, "CRYO_APC", 8))
         return AVPROBE_SCORE_MAX;
 
     return 0;
 }
 
 static int apc_read_header(AVFormatContext *s, AVFormatParameters *ap)
 {

     ByteIOContext *pb = s->pb;

     AVStream *st;
 
     get_le32(pb); /* CRYO */
     get_le32(pb); /* _APC */
     get_le32(pb); /* 1.20 */
 
     st = av_new_stream(s, 0);
     if (!st)

         return AVERROR(ENOMEM);

 
     st->codec->codec_type = CODEC_TYPE_AUDIO;
     st->codec->codec_id = CODEC_ID_ADPCM_IMA_WS;
 
     get_le32(pb); /* number of samples */
     st->codec->sample_rate = get_le32(pb);
 
     st->codec->extradata_size = 2 * 4;
     st->codec->extradata = av_malloc(st->codec->extradata_size +
                                      FF_INPUT_BUFFER_PADDING_SIZE);
     if (!st->codec->extradata)

         return AVERROR(ENOMEM);

 
     /* initial predictor values for adpcm decoder */
     get_buffer(pb, st->codec->extradata, 2 * 4);
 
     st->codec->channels = 1;
     if (get_le32(pb))
         st->codec->channels = 2;
 

     st->codec->bits_per_coded_sample = 4;
     st->codec->bit_rate = st->codec->bits_per_coded_sample * st->codec->channels

                           * st->codec->sample_rate;
     st->codec->block_align = 1;
 
     return 0;
 }
 
 #define MAX_READ_SIZE 4096
 
 static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
 {

     if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0)

         return AVERROR(EIO);

     pkt->stream_index = 0;
     return 0;
 }
 
 AVInputFormat apc_demuxer = {
     "apc",

     NULL_IF_CONFIG_SMALL("CRYO APC format"),

     0,
     apc_probe,
     apc_read_header,
     apc_read_packet,
 };