text: /*
   * RAW DTS demuxer
   * Copyright (c) 2008 Benjamin Larsson
   *
   * 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 "libavcodec/bytestream.h"
  #include "avformat.h"
  #include "rawdec.h"
  
  #define DCA_MARKER_14B_BE 0x1FFFE800
  #define DCA_MARKER_14B_LE 0xFF1F00E8
  #define DCA_MARKER_RAW_BE 0x7FFE8001
  #define DCA_MARKER_RAW_LE 0xFE7F0180
  
  static int dts_probe(AVProbeData *p)
  {
      const uint8_t *buf, *bufp;
      uint32_t state = -1;
      int markers[3] = {0};
      int sum, max;
  
      buf = p->buf;
  
      for(; buf < (p->buf+p->buf_size)-2; buf+=2) {
          bufp = buf;
          state = (state << 16) | bytestream_get_be16(&bufp);
  
          /* regular bitstream */
          if (state == DCA_MARKER_RAW_BE || state == DCA_MARKER_RAW_LE)
              markers[0]++;
  
          /* 14 bits big-endian bitstream */
          if (state == DCA_MARKER_14B_BE)
              if ((bytestream_get_be16(&bufp) & 0xFFF0) == 0x07F0)
                  markers[1]++;
  
          /* 14 bits little-endian bitstream */
          if (state == DCA_MARKER_14B_LE)
              if ((bytestream_get_be16(&bufp) & 0xF0FF) == 0xF007)
                  markers[2]++;
      }
      sum = markers[0] + markers[1] + markers[2];
      max = markers[1] > markers[0];
      max = markers[2] > markers[max] ? 2 : max;
      if (markers[max] > 3 && p->buf_size / markers[max] < 32*1024 &&
          markers[max] * 4 > sum * 3)
          return AVPROBE_SCORE_EXTENSION + 1;
  
      return 0;
  }
  
  AVInputFormat ff_dts_demuxer = {
      .name           = "dts",
      .long_name      = NULL_IF_CONFIG_SMALL("raw DTS"),
      .read_probe     = dts_probe,
      .read_header    = ff_raw_audio_read_header,
      .read_packet    = ff_raw_read_partial_packet,
      .flags          = AVFMT_GENERIC_INDEX,
      .extensions     = "dts",
      .raw_codec_id   = AV_CODEC_ID_DTS,
  };
  