modules/codec/scte18.h

   1 /*****************************************************************************
   2  * scte18.h : SCTE-18 EAS decoder
   3  *****************************************************************************
   4  * Copyright (C) 2016 - VideoLAN Authors
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU Lesser General Public License as published by
   8  * the Free Software Foundation; either version 2.1 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  *****************************************************************************/
  19 #ifndef VLC_SCTE18_H
  20 #define VLC_SCTE18_H
  21
  22 #define SCTE18_SI_BASE_PID 0x1FFB
  23 #define SCTE18_TABLE_ID    0xD8
  24 #define SCTE18_DESCRIPTION N_("Emergency Alert Messaging for Cable")
  25
  26 enum
  27 {
  28     EAS_PRIORITY_TEST = 0,
  29     EAS_PRIORITY_LOW = 3,
  30     EAS_PRIORITY_MEDIUM = 7,
  31     EAS_PRIORITY_HIGH = 11,
  32     EAS_PRIORITY_MAX = 15
  33 };
  34
  35 /* Get priority without decoding
  36  */
  37 static inline int scte18_get_EAS_priority( const uint8_t *p_buffer, size_t i_buffer )
  38 {
  39     if( i_buffer < 17 || p_buffer[0] )
  40         return -1;
  41
  42     size_t i_offset = 6;
  43     size_t i_len = p_buffer[i_offset]; /* EAS code Len */
  44     i_offset += i_len + 1; /* EAS code Text */
  45     if( i_offset >= i_buffer )
  46         return -1;
  47
  48     i_len = p_buffer[i_offset]; /* NOA Len */
  49     i_offset += i_len + 1; /* NOA Text */
  50
  51     i_offset += 1 + 4 + 2 + 1;
  52
  53     if( i_offset >= i_buffer )
  54         return -1;
  55
  56     return (p_buffer[i_offset] & 0x0f);
  57 }
  58
  59 #endif