modules/codec/cc.h

   1 /*****************************************************************************
   2  * cc.h
   3  *****************************************************************************
   4  * Copyright (C) 2007 Laurent Aimar
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef _CC_H
  25 #define _CC_H 1
  26
  27 #include <vlc_bits.h>
  28
  29 /* CC have a maximum rate of 9600 bit/s (per field?) */
  30 #define CC_MAX_DATA_SIZE (2 * 3*600)
  31 typedef struct
  32 {
  33     /* Which channel are present */
  34     bool pb_present[4];
  35
  36     /* */
  37     bool b_reorder;
  38
  39     /* CC data per field
  40      *  byte[x+0]: field (0/1)
  41      *  byte[x+1]: cc data 1
  42      *  byte[x+2]: cc data 2
  43      */
  44     int     i_data;
  45     uint8_t p_data[CC_MAX_DATA_SIZE];
  46 } cc_data_t;
  47
  48 static inline void cc_Init( cc_data_t *c )
  49 {
  50     int i;
  51
  52     for( i = 0; i < 4; i++ )
  53         c-> pb_present[i] = false;
  54     c->i_data = 0;
  55     c->b_reorder = false;
  56 }
  57 static inline void cc_Exit( cc_data_t *c )
  58 {
  59     VLC_UNUSED(c);
  60     return;
  61 }
  62 static inline void cc_Flush( cc_data_t *c )
  63 {
  64     c->i_data = 0;
  65 }
  66
  67 static inline void cc_AppendData( cc_data_t *c, int i_field, const uint8_t cc[2] )
  68 {
  69     if( i_field == 0 || i_field == 1 )
  70     {
  71         c->pb_present[2*i_field+0] =
  72         c->pb_present[2*i_field+1] = true;
  73     }
  74
  75     c->p_data[c->i_data++] = i_field;
  76     c->p_data[c->i_data++] = cc[0];
  77     c->p_data[c->i_data++] = cc[1];
  78 }
  79
  80 static inline void cc_Extract( cc_data_t *c, bool b_top_field_first, const uint8_t *p_src, int i_src )
  81 {
  82     static const uint8_t p_cc_ga94[4] = { 0x47, 0x41, 0x39, 0x34 };
  83     static const uint8_t p_cc_dvd[4] = { 0x43, 0x43, 0x01, 0xf8 };
  84     static const uint8_t p_cc_replaytv4a[2] = { 0xbb, 0x02 };
  85     static const uint8_t p_cc_replaytv4b[2] = { 0xcc, 0x02 };
  86     static const uint8_t p_cc_replaytv5a[2] = { 0x99, 0x02 };
  87     static const uint8_t p_cc_replaytv5b[2] = { 0xaa, 0x02 };
  88     static const uint8_t p_cc_scte20[2] = { 0x03, 0x81 };
  89     static const uint8_t p_cc_scte20_old[2] = { 0x03, 0x01 };
  90     //static const uint8_t p_afd_start[4] = { 0x44, 0x54, 0x47, 0x31 };
  91
  92     if( i_src < 4 )
  93         return;
  94
  95     if( !memcmp( p_cc_ga94, p_src, 4 ) && i_src >= 5+1+1+1 && p_src[4] == 0x03 )
  96     {
  97         /* Extract CC from DVB/ATSC TS */
  98         /* cc_data()
  99          *          u1 reserved(1)
 100          *          u1 process_cc_data_flag
 101          *          u1 additional_data_flag
 102          *          u5 cc_count
 103          *          u8 reserved(1111 1111)
 104          *          for cc_count
 105          *              u5 marker bit(1111 1)
 106          *              u1 cc_valid
 107          *              u2 cc_type
 108          *              u8 cc_data_1
 109          *              u8 cc_data_2
 110          *          u8 marker bit(1111 1111)
 111          *          if additional_data_flag
 112          *              unknown
 113          */
 114         /* cc_type:
 115          *  0x00: field 1
 116          *  0x01: field 2
 117          */
 118         const uint8_t *cc = &p_src[5];
 119         const int i_count_cc = cc[0]&0x1f;
 120         int i;
 121
 122         if( !(cc[0]&0x40) ) // process flag
 123             return;
 124         if( i_src < 5 + 1+1 + i_count_cc*3 + 1)  // broken packet
 125             return;
 126         if( i_count_cc <= 0 )   // no cc present
 127             return;
 128         if( cc[2+i_count_cc * 3] != 0xff )  // marker absent
 129             return;
 130         cc += 2;
 131
 132         for( i = 0; i < i_count_cc; i++, cc += 3 )
 133         {
 134             int i_field = cc[0] & 0x03;
 135             if( ( cc[0] & 0xfc ) != 0xfc )
 136                 continue;
 137             if( i_field != 0 && i_field != 1 )
 138                 continue;
 139             if( c->i_data + 3 > CC_MAX_DATA_SIZE )
 140                 continue;
 141
 142             cc_AppendData( c, i_field, &cc[1] );
 143         }
 144         c->b_reorder = true;
 145     }
 146     else if( !memcmp( p_cc_dvd, p_src, 4 ) && i_src > 4+1 )
 147     {
 148         /* DVD CC */
 149         const int b_truncate = p_src[4] & 0x01;
 150         const int i_field_first = (p_src[4] & 0x80) ? 0 : 1;
 151         const int i_count_cc2 = (p_src[4] >> 1) & 0xf;
 152         const uint8_t *cc = &p_src[5];
 153         int i;
 154
 155         if( i_src < 4+1+6*i_count_cc2 - ( b_truncate ? 3 : 0) )
 156             return;
 157         for( i = 0; i < i_count_cc2; i++ )
 158         {
 159             int j;
 160             for( j = 0; j < 2; j++, cc += 3 )
 161             {
 162                 const int i_field = j == i_field_first ? 0 : 1;
 163
 164                 if( b_truncate && i == i_count_cc2 - 1 && j == 1 )
 165                     break;
 166                 if( cc[0] != 0xff && cc[0] != 0xfe )
 167                     continue;
 168                 if( c->i_data + 3 > CC_MAX_DATA_SIZE )
 169                     continue;
 170
 171                 cc_AppendData( c, i_field, &cc[1] );
 172             }
 173         }
 174         c->b_reorder = false;
 175     }
 176     else if( i_src >= 2+2 + 2+2 &&
 177              ( ( !memcmp( p_cc_replaytv4a, &p_src[0], 2 ) && !memcmp( p_cc_replaytv4b, &p_src[4], 2 ) ) ||
 178                ( !memcmp( p_cc_replaytv5a, &p_src[0], 2 ) && !memcmp( p_cc_replaytv5b, &p_src[4], 2 ) ) ) )
 179     {
 180         /* ReplayTV CC */
 181         const uint8_t *cc = &p_src[0];
 182         int i;
 183         if( c->i_data + 2*3 > CC_MAX_DATA_SIZE )
 184             return;
 185
 186         for( i = 0; i < 2; i++, cc += 4 )
 187         {
 188             const int i_field = i == 0 ? 1 : 0;
 189
 190             cc_AppendData( c, i_field, &cc[2] );
 191         }
 192         c->b_reorder = false;
 193     }
 194     else if( ( !memcmp( p_cc_scte20, p_src, 2 ) ||
 195                !memcmp( p_cc_scte20_old, p_src, 2 ) ) && i_src > 2 )
 196     {
 197         /* SCTE-20 CC */
 198         bs_t s;
 199         bs_init( &s, &p_src[2], i_src - 2 );
 200         const int i_cc_count = bs_read( &s, 5 );
 201         for( int i = 0; i < i_cc_count; i++ )
 202         {
 203             bs_skip( &s, 2 );
 204             const int i_field_idx = bs_read( &s, 2 );
 205             bs_skip( &s, 5 );
 206             uint8_t cc[2];
 207             for( int j = 0; j < 2; j++ )
 208             {
 209                 cc[j] = 0;
 210                 for( int k = 0; k < 8; k++ )
 211                     cc[j] |= bs_read( &s, 1 ) << k;
 212             }
 213             bs_skip( &s, 1 );
 214
 215             if( i_field_idx == 0 )
 216                 continue;
 217             if( c->i_data + 2*3 > CC_MAX_DATA_SIZE )
 218                 continue;
 219
 220             /* 1,2,3 -> 0,1,0. I.E. repeated field 3 is merged with field 1 */
 221             int i_field = ((i_field_idx - 1) & 1);
 222             if (!b_top_field_first)
 223                 i_field ^= 1;
 224
 225             cc_AppendData( c, i_field, &cc[0] );
 226         }
 227         c->b_reorder = true;
 228     }
 229     else
 230     {
 231 #if 0
 232 #define V(x) ( ( x < 0x20 || x >= 0x7f ) ? '?' : x )
 233         fprintf( stderr, "-------------- unknown user data " );
 234         for( int i = 0; i < i_src; i++ )
 235             fprintf( stderr, "%2.2x ", p_src[i] );
 236         for( int i = 0; i < i_src; i++ )
 237             fprintf( stderr, "%c ", V(p_src[i]) );
 238         fprintf( stderr, "\n" );
 239 #undef V
 240 #endif
 241         /* TODO DVD CC, ... */
 242     }
 243 }
 244
 245 #endif /* _CC_H */
 246