/*
  * ADP demuxer
  * Copyright (c) 2013 James Almer
  *
  * 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/channel_layout.h"
 #include "libavutil/intreadwrite.h"
 #include "avformat.h"
 #include "internal.h"
 
 static int adp_probe(AVProbeData *p)
 {

     int i, changes = 0;

     uint8_t last = 0;

 
     if (p->buf_size < 32)
         return 0;
 

     for (i = 0; i < p->buf_size - 3; i+=32) {

         if (p->buf[i] != p->buf[i+2] || p->buf[i+1] != p->buf[i+3])
             return 0;

         if (p->buf[i] != last)
             changes++;
         last = p->buf[i];
     }
     if (changes <= 1)
         return 0;

 
     return p->buf_size < 260 ? 1 : AVPROBE_SCORE_MAX / 4;
 }
 
 static int adp_read_header(AVFormatContext *s)
 {
     AVStream *st;
 
     st = avformat_new_stream(s, NULL);
     if (!st)
         return AVERROR(ENOMEM);
 

     st->codecpar->codec_type     = AVMEDIA_TYPE_AUDIO;
     st->codecpar->codec_id       = AV_CODEC_ID_ADPCM_DTK;
     st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
     st->codecpar->channels       = 2;
     st->codecpar->sample_rate    = 48000;

     st->start_time            = 0;

     if (s->pb->seekable & AVIO_SEEKABLE_NORMAL)

         st->duration          = av_get_audio_frame_duration2(st->codecpar, avio_size(s->pb));

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

 
     return 0;
 }
 
 static int adp_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     int ret, size = 1024;
 

     if (avio_feof(s->pb))

         return AVERROR_EOF;
 
     ret = av_get_packet(s->pb, pkt, size);
 
     if (ret != size) {
         if (ret < 0) {

             av_packet_unref(pkt);

             return ret;
         }
         av_shrink_packet(pkt, ret);
     }
     pkt->stream_index = 0;
 
     return ret;
 }
 
 AVInputFormat ff_adp_demuxer = {
     .name           = "adp",
     .long_name      = NULL_IF_CONFIG_SMALL("ADP"),
     .read_probe     = adp_probe,
     .read_header    = adp_read_header,
     .read_packet    = adp_read_packet,
     .extensions     = "adp,dtk",
 };