/*
  * Black ops audio demuxer
  * Copyright (c) 2013 Michael Niedermayer
  *
  * 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"

 
 static int probe(AVProbeData *p)
 {
     if (p->buf_size < 2096)
         return 0;
     if (   AV_RL32(p->buf     ) != 1
         || AV_RL32(p->buf +  8) > 100000
         || AV_RL32(p->buf + 12) > 8
         || AV_RL32(p->buf + 16) != 2096
         ||!AV_RL32(p->buf + 21)
         || AV_RL16(p->buf + 25) != 2096
         || AV_RL32(p->buf + 48) % AV_RL32(p->buf + 21)
         )
         return 0;

     return AVPROBE_SCORE_EXTENSION;

 }
 
 
 static int read_header(AVFormatContext *s)
 {
     AVStream *st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
 
     st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
     st->codec->codec_id = AV_CODEC_ID_ADPCM_MS;
 
     avio_rl32(s->pb);
     avio_rl32(s->pb);
     st->codec->sample_rate = avio_rl32(s->pb);
     st->codec->channels    = avio_rl32(s->pb);

     s->internal->data_offset = avio_rl32(s->pb);

     avio_r8(s->pb);
     st->codec->block_align = st->codec->channels * avio_rl32(s->pb);
 

     avio_seek(s->pb, s->internal->data_offset, SEEK_SET);

 
     return 0;
 }
 
 static int read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     AVStream *st = s->streams[0];
 
     return av_get_packet(s->pb, pkt, st->codec->block_align);
 }
 
 AVInputFormat ff_boa_demuxer = {
     .name           = "boa",
     .long_name      = NULL_IF_CONFIG_SMALL("Black Ops Audio"),
     .read_probe     = probe,
     .read_header    = read_header,
     .read_packet    = read_packet,
     .flags          = AVFMT_GENERIC_INDEX,
 };