text: /*
   * RAW dvb teletext demuxer
   * Copyright (c) 2016 Marton Balnt <cus@passwd.hu>
   *
   * 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/dvbtxt.h"
  
  #include "avformat.h"
  #include "rawdec.h"
  
  static int dvbtxt_probe(const AVProbeData *p)
  {
      const uint8_t *end = p->buf + p->buf_size;
      const uint8_t *buf;
  
      /* The purpose of this is demuxer is to detect DVB teletext streams in
       * mpegts, so we reject invalid buffer sizes */
      if ((p->buf_size + 45) % 184 != 0)
          return 0;
  
      if (!ff_data_identifier_is_teletext(p->buf[0]))
          return 0;
  
      for (buf = p->buf + 1; buf < end; buf += 46) {
          if (!ff_data_unit_id_is_teletext(buf[0]) && buf[0] != 0xff)
              return 0;
          if (buf[1] != 0x2c)     // data_unit_length
              return 0;
      }
  
      return AVPROBE_SCORE_MAX / 2;
  }
  
  FF_DEF_RAWSUB_DEMUXER(dvbtxt, "dvbtxt", dvbtxt_probe, NULL, AV_CODEC_ID_DVB_TELETEXT, 0)
  