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 it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef VLC_CC_H_
  25 #define VLC_CC_H_
  26
  27 #include <vlc_bits.h>
  28
  29 #define BLOCK_FLAG_ORDERED_CAPTIONS (0x01 << BLOCK_FLAG_PRIVATE_SHIFT)
  30
  31 #define CC_PKT_BYTE0(field) (0xFC | (0x03 & field))
  32
  33 /* CC have a maximum rate of 9600 bit/s (per field?) */
  34 #define CC_MAX_DATA_SIZE (2 * 3*600)
  35 enum cc_payload_type_e
  36 {
  37     CC_PAYLOAD_NONE,
  38     CC_PAYLOAD_GA94,
  39     CC_PAYLOAD_DVD,
  40     CC_PAYLOAD_REPLAYTV,
  41     CC_PAYLOAD_SCTE20,
  42 };
  43 typedef struct
  44 {
  45     /* Which channel are present */
  46     bool pb_present[4];
  47
  48     /* */
  49     bool b_reorder;
  50
  51     /* */
  52     enum cc_payload_type_e i_payload_type;
  53     int i_payload_other_count;
  54
  55     /* CC data per field
  56      *  byte[x+0]: field (0/1)
  57      *  byte[x+1]: cc data 1
  58      *  byte[x+2]: cc data 2
  59      */
  60     int     i_data;
  61     uint8_t p_data[CC_MAX_DATA_SIZE];
  62 } cc_data_t;
  63
  64 static inline void cc_Init( cc_data_t *c )
  65 {
  66     int i;
  67
  68     for( i = 0; i < 4; i++ )
  69         c-> pb_present[i] = false;
  70     c->i_data = 0;
  71     c->b_reorder = false;
  72     c->i_payload_type = CC_PAYLOAD_NONE;
  73     c->i_payload_other_count = 0;
  74 }
  75 static inline void cc_Exit( cc_data_t *c )
  76 {
  77     VLC_UNUSED(c);
  78     return;
  79 }
  80 static inline void cc_Flush( cc_data_t *c )
  81 {
  82     c->i_data = 0;
  83 }
  84
  85 static inline void cc_AppendData( cc_data_t *c, uint8_t cc_preamble, const uint8_t cc[2] )
  86 {
  87     uint8_t i_field = cc_preamble & 0x03;
  88     if( i_field == 0 || i_field == 1 )
  89     {
  90         c->pb_present[2*i_field+0] =
  91         c->pb_present[2*i_field+1] = true;
  92     }
  93
  94     c->p_data[c->i_data++] = cc_preamble;
  95     c->p_data[c->i_data++] = cc[0];
  96     c->p_data[c->i_data++] = cc[1];
  97 }
  98
  99 static inline void cc_Extract( cc_data_t *c, enum cc_payload_type_e i_payload_type,
 100                                bool b_top_field_first, const uint8_t *p_src, int i_src )
 101 {
 102     if( c->i_payload_type != CC_PAYLOAD_NONE && c->i_payload_type != i_payload_type )
 103     {
 104         c->i_payload_other_count++;
 105         if( c->i_payload_other_count < 50 )
 106             return;
 107     }
 108     c->i_payload_type        = i_payload_type;
 109     c->i_payload_other_count = 0;
 110
 111     if( i_payload_type == CC_PAYLOAD_GA94 )
 112     {
 113         /* cc_data()
 114          *          u1 reserved(1)
 115          *          u1 process_cc_data_flag
 116          *          u1 additional_data_flag
 117          *          u5 cc_count
 118          *          u8 reserved(1111 1111)
 119          *          for cc_count
 120          *              u5 marker bit(1111 1)
 121          *              u1 cc_valid
 122          *              u2 cc_type
 123          *              u8 cc_data_1
 124          *              u8 cc_data_2
 125          *          u8 marker bit(1111 1111)
 126          *          if additional_data_flag
 127          *              unknown
 128          */
 129         /* cc_type:
 130          *  0x00: field 1
 131          *  0x01: field 2
 132          */
 133         const uint8_t *cc = &p_src[0];
 134         const int i_count_cc = cc[0]&0x1f;
 135         int i;
 136
 137         if( !(cc[0]&0x40) ) // process flag
 138             return;
 139         if( i_src < 1+1 + i_count_cc*3 + 1)  // broken packet
 140             return;
 141         if( i_count_cc <= 0 )   // no cc present
 142             return;
 143         if( cc[2+i_count_cc * 3] != 0xff )  // marker absent
 144             return;
 145         cc += 2;
 146
 147         for( i = 0; i < i_count_cc; i++, cc += 3 )
 148         {
 149             if( c->i_data + 3 > CC_MAX_DATA_SIZE )
 150                 break;
 151
 152             cc_AppendData( c, cc[0], &cc[1] );
 153         }
 154         c->b_reorder = true;
 155     }
 156     else if( i_payload_type == CC_PAYLOAD_DVD )
 157     {
 158         /* user_data
 159          *          (u32 stripped earlier)
 160          *          u32 (0x43 0x43 0x01 0xf8)
 161          *          u1 caption_odd_field_first (CC1/CC2)
 162          *          u1 caption_filler
 163          *          u5 cc_block_count  (== cc_count / 2)
 164          *          u1 caption_extra_field_added (because odd cc_count)
 165          *          for cc_block_count * 2 + caption_extra_field_added
 166          *              u7 cc_filler_1
 167          *              u1 cc_field_is_odd
 168          *              u8 cc_data_1
 169          *              u8 cc_data_2
 170          */
 171         const int b_truncate = p_src[4] & 0x01;
 172         const int i_field_first = (p_src[4] & 0x80) ? 0 : 1;
 173         const int i_count_cc2 = (p_src[4] >> 1) & 0xf;
 174         const uint8_t *cc = &p_src[5];
 175         int i;
 176
 177         if( i_src < 4+1+6*i_count_cc2 - ( b_truncate ? 3 : 0) )
 178             return;
 179         for( i = 0; i < i_count_cc2; i++ )
 180         {
 181             int j;
 182             for( j = 0; j < 2; j++, cc += 3 )
 183             {
 184                 const int i_field = j == i_field_first ? 0 : 1;
 185
 186                 if( b_truncate && i == i_count_cc2 - 1 && j == 1 )
 187                     break;
 188                 if( (cc[0] & 0xfe) != 0xfe )
 189                     continue;
 190                 if( c->i_data + 3 > CC_MAX_DATA_SIZE )
 191                     continue;
 192
 193                 cc_AppendData( c, CC_PKT_BYTE0(i_field), &cc[1] );
 194             }
 195         }
 196         c->b_reorder = false;
 197     }
 198     else if( i_payload_type == CC_PAYLOAD_REPLAYTV )
 199     {
 200         const uint8_t *cc = &p_src[0];
 201         for( int i_cc_count = i_src >> 2; i_cc_count > 0;
 202              i_cc_count--, cc += 4 )
 203         {
 204             if( c->i_data + 3 > CC_MAX_DATA_SIZE )
 205                 return;
 206             uint8_t i_field = (cc[0] & 0x02) >> 1;
 207             cc_AppendData( c, CC_PKT_BYTE0(i_field), &cc[2] );
 208         }
 209         c->b_reorder = false;
 210     }
 211     else /* CC_PAYLOAD_SCTE20 */
 212     {
 213         /* user_data(2)
 214          *          (u32 stripped earlier)
 215          *          u16 p_cc_scte20
 216          *          u5 cc_count
 217          *          for cc_count
 218          *              u2 cc_priority
 219          *              u2 cc_field_num
 220          *              u5 cc_line_offset
 221          *              u8 cc_data_1[1:8]
 222          *              u8 cc_data_2[1:8]
 223          *              u1 marker bit
 224          *          un additional_realtimevideodata
 225          *          un reserved
 226          */
 227         bs_t s;
 228         bs_init( &s, &p_src[2], i_src - 2 );
 229         const int i_cc_count = bs_read( &s, 5 );
 230         for( int i = 0; i < i_cc_count; i++ )
 231         {
 232             bs_skip( &s, 2 );
 233             const int i_field_idx = bs_read( &s, 2 );
 234             bs_skip( &s, 5 );
 235             uint8_t cc[2];
 236             for( int j = 0; j < 2; j++ )
 237             {
 238                 cc[j] = 0;
 239                 for( int k = 0; k < 8; k++ )
 240                     cc[j] |= bs_read( &s, 1 ) << k;
 241             }
 242             bs_skip( &s, 1 );
 243
 244             if( i_field_idx == 0 )
 245                 continue;
 246             if( c->i_data + 2*3 > CC_MAX_DATA_SIZE )
 247                 continue;
 248
 249             /* 1,2,3 -> 0,1,0. I.E. repeated field 3 is merged with field 1 */
 250             int i_field = ((i_field_idx - 1) & 1);
 251             if (!b_top_field_first)
 252                 i_field ^= 1;
 253
 254             cc_AppendData( c, CC_PKT_BYTE0(i_field), &cc[0] );
 255         }
 256         c->b_reorder = true;
 257     }
 258 }
 259
 260
 261 static inline void cc_ProbeAndExtract( cc_data_t *c, bool b_top_field_first, const uint8_t *p_src, int i_src )
 262 {
 263     static const uint8_t p_cc_ga94[4] = { 0x47, 0x41, 0x39, 0x34 };
 264     static const uint8_t p_cc_dvd[4] = { 0x43, 0x43, 0x01, 0xf8 }; /* ascii 'CC', type_code, cc_block_size */
 265     static const uint8_t p_cc_replaytv4a[2] = { 0xbb, 0x02 };/* RTV4K, BB02xxxxCC02 */
 266     static const uint8_t p_cc_replaytv4b[2] = { 0xcc, 0x02 };/* see DVR-ClosedCaption in samples */
 267     static const uint8_t p_cc_replaytv5a[2] = { 0x99, 0x02 };/* RTV5K, 9902xxxxAA02 */
 268     static const uint8_t p_cc_replaytv5b[2] = { 0xaa, 0x02 };/* see DVR-ClosedCaption in samples */
 269     static const uint8_t p_cc_scte20[2] = { 0x03, 0x81 };    /* user_data_type_code, SCTE 20 */
 270     static const uint8_t p_cc_scte20_old[2] = { 0x03, 0x01 };/* user_data_type_code, old, Note 1 */
 271
 272     if( i_src < 4 )
 273         return;
 274
 275     enum cc_payload_type_e i_payload_type;
 276     if( !memcmp( p_cc_ga94, p_src, 4 ) && i_src >= 5+1+1+1 && p_src[4] == 0x03 )
 277     {
 278         /* CC from DVB/ATSC TS */
 279         i_payload_type = CC_PAYLOAD_GA94;
 280         i_src -= 5;
 281         p_src += 5;
 282     }
 283     else if( !memcmp( p_cc_dvd, p_src, 4 ) && i_src > 4+1 )
 284     {
 285         i_payload_type = CC_PAYLOAD_DVD;
 286     }
 287     else if( i_src >= 2+2 + 2+2 &&
 288              ( ( !memcmp( p_cc_replaytv4a, &p_src[0], 2 ) && !memcmp( p_cc_replaytv4b, &p_src[4], 2 ) ) ||
 289                ( !memcmp( p_cc_replaytv5a, &p_src[0], 2 ) && !memcmp( p_cc_replaytv5b, &p_src[4], 2 ) ) ) )
 290     {
 291         i_payload_type = CC_PAYLOAD_REPLAYTV;
 292     }
 293     else if( ( !memcmp( p_cc_scte20, p_src, 2 ) ||
 294                !memcmp( p_cc_scte20_old, p_src, 2 ) ) && i_src > 2 )
 295     {
 296         i_payload_type = CC_PAYLOAD_SCTE20;
 297     }
 298     else if (p_src[0] == 0x03 && p_src[1] == i_src - 2) /* DIRECTV */
 299     {
 300         i_payload_type = CC_PAYLOAD_GA94;
 301         i_src -= 2;
 302         p_src += 2;
 303     }
 304     else
 305     {
 306 #if 0
 307 #define V(x) ( ( x < 0x20 || x >= 0x7f ) ? '?' : x )
 308         fprintf( stderr, "-------------- unknown user data " );
 309         for( int i = 0; i < i_src; i++ )
 310             fprintf( stderr, "%2.2x ", p_src[i] );
 311         for( int i = 0; i < i_src; i++ )
 312             fprintf( stderr, "%c ", V(p_src[i]) );
 313         fprintf( stderr, "\n" );
 314 #undef V
 315 #endif
 316         return;
 317     }
 318
 319     cc_Extract( c, i_payload_type, b_top_field_first, p_src, i_src );
 320 }
 321
 322 #endif /* _CC_H */
 323