modules/codec/telx.c

   1 /*****************************************************************************
   2  * telx.c : Minimalistic Teletext subtitles decoder
   3  *****************************************************************************
   4  * Copyright (C) 2007 Vincent Penne
   5  * Some code converted from ProjectX java dvb decoder (c) 2001-2005 by dvb.matt
   6  * $Id$
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22 /*****************************************************************************
  23  *
  24  * information on teletext format can be found here :
  25  * http://pdc.ro.nu/teletext.html
  26  *
  27  *****************************************************************************/
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31 #include <assert.h>
  32 #include <stdint.h>
  33
  34 #include <vlc_common.h>
  35 #include <vlc_plugin.h>
  36
  37 #include <vlc_bits.h>
  38 #include <vlc_codec.h>
  39
  40 /* #define TELX_DEBUG */
  41 #ifdef TELX_DEBUG
  42 #   define dbg( a ) msg_Dbg a
  43 #else
  44 #   define dbg( a )
  45 #endif
  46
  47 /*****************************************************************************
  48  * Module descriptor.
  49  *****************************************************************************/
  50 static int  Open ( vlc_object_t * );
  51 static void Close( vlc_object_t * );
  52 static subpicture_t *Decode( decoder_t *, block_t ** );
  53
  54 #define OVERRIDE_PAGE_TEXT N_("Override page")
  55 #define OVERRIDE_PAGE_LONGTEXT N_("Override the indicated page, try this if " \
  56         "your subtitles don't appear (-1 = autodetect from TS, " \
  57         "0 = autodetect from teletext, " \
  58         ">0 = actual page number, usually 888 or 889).")
  59
  60 #define IGNORE_SUB_FLAG_TEXT N_("Ignore subtitle flag")
  61 #define IGNORE_SUB_FLAG_LONGTEXT N_("Ignore the subtitle flag, try this if " \
  62         "your subtitles don't appear.")
  63
  64 #define FRENCH_WORKAROUND_TEXT N_("Workaround for France")
  65 #define FRENCH_WORKAROUND_LONGTEXT N_("Some French channels do not flag " \
  66         "their subtitling pages correctly due to a historical " \
  67         "interpretation mistake. Try using this wrong interpretation if " \
  68         "your subtitles don't appear.")
  69
  70 vlc_module_begin ()
  71     set_description( N_("Teletext subtitles decoder") )
  72     set_shortname( "Teletext" )
  73     set_capability( "decoder", 50 )
  74     set_category( CAT_INPUT )
  75     set_subcategory( SUBCAT_INPUT_SCODEC )
  76     set_callbacks( Open, Close )
  77
  78     add_integer( "telx-override-page", -1, NULL,
  79                  OVERRIDE_PAGE_TEXT, OVERRIDE_PAGE_LONGTEXT, true )
  80     add_bool( "telx-ignore-subtitle-flag", false, NULL,
  81               IGNORE_SUB_FLAG_TEXT, IGNORE_SUB_FLAG_LONGTEXT, true )
  82     add_bool( "telx-french-workaround", false, NULL,
  83               FRENCH_WORKAROUND_TEXT, FRENCH_WORKAROUND_LONGTEXT, true )
  84
  85 vlc_module_end ()
  86
  87 /****************************************************************************
  88  * Local structures
  89  ****************************************************************************/
  90
  91 struct decoder_sys_t
  92 {
  93   int         i_align;
  94   bool        b_is_subtitle[9];
  95   char        ppsz_lines[32][128];
  96   char        psz_prev_text[512];
  97   mtime_t     prev_pts;
  98   int         i_page[9];
  99   bool        b_erase[9];
 100   const uint16_t *  pi_active_national_set[9];
 101   int         i_wanted_page, i_wanted_magazine;
 102   bool        b_ignore_sub_flag;
 103 };
 104
 105 /****************************************************************************
 106  * Local data
 107  ****************************************************************************/
 108
 109 /*
 110  * My doc only mentions 13 national characters, but experiments show there
 111  * are more, in france for example I already found two more (0x9 and 0xb).
 112  *
 113  * Conversion is in this order :
 114  *
 115  * 0x23 0x24 0x40 0x5b 0x5c 0x5d 0x5e 0x5f 0x60 0x7b 0x7c 0x7d 0x7e
 116  * (these are the standard ones)
 117  * 0x08 0x09 0x0a 0x0b 0x0c 0x0d (apparently a control character) 0x0e 0x0f
 118  */
 119
 120 static const uint16_t ppi_national_subsets[][20] =
 121 {
 122   { 0x00a3, 0x0024, 0x0040, 0x00ab, 0x00bd, 0x00bb, 0x005e, 0x0023,
 123     0x002d, 0x00bc, 0x00a6, 0x00be, 0x00f7 }, /* english ,000 */
 124
 125   { 0x00e9, 0x00ef, 0x00e0, 0x00eb, 0x00ea, 0x00f9, 0x00ee, 0x0023,
 126     0x00e8, 0x00e2, 0x00f4, 0x00fb, 0x00e7, 0, 0x00eb, 0, 0x00ef }, /* french  ,001 */
 127
 128   { 0x0023, 0x00a4, 0x00c9, 0x00c4, 0x00d6, 0x00c5, 0x00dc, 0x005f,
 129     0x00e9, 0x00e4, 0x00f6, 0x00e5, 0x00fc }, /* swedish,finnish,hungarian ,010 */
 130
 131   { 0x0023, 0x016f, 0x010d, 0x0165, 0x017e, 0x00fd, 0x00ed, 0x0159,
 132     0x00e9, 0x00e1, 0x011b, 0x00fa, 0x0161 }, /* czech,slovak  ,011 */
 133
 134   { 0x0023, 0x0024, 0x00a7, 0x00c4, 0x00d6, 0x00dc, 0x005e, 0x005f,
 135     0x00b0, 0x00e4, 0x00f6, 0x00fc, 0x00df }, /* german ,100 */
 136
 137   { 0x00e7, 0x0024, 0x00a1, 0x00e1, 0x00e9, 0x00ed, 0x00f3, 0x00fa,
 138     0x00bf, 0x00fc, 0x00f1, 0x00e8, 0x00e0 }, /* portuguese,spanish ,101 */
 139
 140   { 0x00a3, 0x0024, 0x00e9, 0x00b0, 0x00e7, 0x00bb, 0x005e, 0x0023,
 141     0x00f9, 0x00e0, 0x00f2, 0x00e8, 0x00ec }, /* italian  ,110 */
 142
 143   { 0x0023, 0x00a4, 0x0162, 0x00c2, 0x015e, 0x0102, 0x00ce, 0x0131,
 144     0x0163, 0x00e2, 0x015f, 0x0103, 0x00ee }, /* rumanian ,111 */
 145
 146   /* I have these tables too, but I don't know how they can be triggered */
 147   { 0x0023, 0x0024, 0x0160, 0x0117, 0x0119, 0x017d, 0x010d, 0x016b,
 148     0x0161, 0x0105, 0x0173, 0x017e, 0x012f }, /* lettish,lithuanian ,1000 */
 149
 150   { 0x0023, 0x0144, 0x0105, 0x005a, 0x015a, 0x0141, 0x0107, 0x00f3,
 151     0x0119, 0x017c, 0x015b, 0x0142, 0x017a }, /* polish,  1001 */
 152
 153   { 0x0023, 0x00cb, 0x010c, 0x0106, 0x017d, 0x0110, 0x0160, 0x00eb,
 154     0x010d, 0x0107, 0x017e, 0x0111, 0x0161 }, /* serbian,croatian,slovenian, 1010 */
 155
 156   { 0x0023, 0x00f5, 0x0160, 0x00c4, 0x00d6, 0x017e, 0x00dc, 0x00d5,
 157     0x0161, 0x00e4, 0x00f6, 0x017e, 0x00fc }, /* estonian  ,1011 */
 158
 159   { 0x0054, 0x011f, 0x0130, 0x015e, 0x00d6, 0x00c7, 0x00dc, 0x011e,
 160     0x0131, 0x015f, 0x00f6, 0x00e7, 0x00fc }, /* turkish  ,1100 */
 161 };
 162
 163
 164 /*****************************************************************************
 165  * Open: probe the decoder and return score
 166  *****************************************************************************
 167  * Tries to launch a decoder and return score so that the interface is able
 168  * to chose.
 169  *****************************************************************************/
 170 static int Open( vlc_object_t *p_this )
 171 {
 172     decoder_t     *p_dec = (decoder_t *) p_this;
 173     decoder_sys_t *p_sys = NULL;
 174     int            i_val;
 175
 176
 177     if( p_dec->fmt_in.i_codec != VLC_CODEC_TELETEXT)
 178     {
 179         return VLC_EGENERIC;
 180     }
 181
 182     p_dec->pf_decode_sub = Decode;
 183     p_sys = p_dec->p_sys = calloc( 1, sizeof(*p_sys) );
 184     if( p_sys == NULL )
 185         return VLC_ENOMEM;
 186     p_dec->fmt_out.i_cat = SPU_ES;
 187     p_dec->fmt_out.i_codec = 0;
 188
 189     p_sys->i_align = 0;
 190     for ( int i = 0; i < 9; i++ )
 191         p_sys->pi_active_national_set[i] = ppi_national_subsets[1];
 192
 193     i_val = var_CreateGetInteger( p_dec, "telx-override-page" );
 194     if( i_val == -1 && p_dec->fmt_in.subs.teletext.i_magazine != -1 &&
 195         ( p_dec->fmt_in.subs.teletext.i_magazine != 1 ||
 196           p_dec->fmt_in.subs.teletext.i_page != 0 ) ) /* ignore if TS demux wants page 100 (unlikely to be sub) */
 197     {
 198         bool b_val;
 199         p_sys->i_wanted_magazine = p_dec->fmt_in.subs.teletext.i_magazine;
 200         p_sys->i_wanted_page = p_dec->fmt_in.subs.teletext.i_page;
 201
 202         b_val = var_CreateGetBool( p_dec, "telx-french-workaround" );
 203         if( p_sys->i_wanted_page < 100 &&
 204             (b_val || (p_sys->i_wanted_page % 16) >= 10))
 205         {
 206             /* See http://www.nada.kth.se/~ragge/vdr/ttxtsubs/TROUBLESHOOTING.txt
 207              * paragraph about French channels - they mix up decimal and
 208              * hexadecimal */
 209             p_sys->i_wanted_page = (p_sys->i_wanted_page / 10) * 16 +
 210                                    (p_sys->i_wanted_page % 10);
 211         }
 212     }
 213     else if( i_val <= 0 )
 214     {
 215         p_sys->i_wanted_magazine = -1;
 216         p_sys->i_wanted_page = -1;
 217     }
 218     else
 219     {
 220         p_sys->i_wanted_magazine = i_val / 100;
 221         p_sys->i_wanted_page = (((i_val % 100) / 10) << 4)
 222                                |((i_val % 100) % 10);
 223     }
 224     p_sys->b_ignore_sub_flag = var_CreateGetBool( p_dec,
 225                                     "telx-ignore-subtitle-flag" );
 226
 227     msg_Dbg( p_dec, "starting telx on magazine %d page %02x flag %d",
 228              p_sys->i_wanted_magazine, p_sys->i_wanted_page,
 229              p_sys->b_ignore_sub_flag );
 230
 231     return VLC_SUCCESS;
 232
 233 /*  error: */
 234 /*     if (p_sys) { */
 235 /*       free(p_sys); */
 236 /*       p_sys = NULL; */
 237 /*     } */
 238 /*     return VLC_EGENERIC; */
 239 }
 240
 241 /*****************************************************************************
 242  * Close:
 243  *****************************************************************************/
 244 static void Close( vlc_object_t *p_this )
 245 {
 246     decoder_t     *p_dec = (decoder_t*) p_this;
 247     decoder_sys_t *p_sys = p_dec->p_sys;
 248
 249     free( p_sys );
 250 }
 251
 252 /**************************
 253  * change bits endianness *
 254  **************************/
 255 static uint8_t bytereverse( int n )
 256 {
 257     n = (((n >> 1) & 0x55) | ((n << 1) & 0xaa));
 258     n = (((n >> 2) & 0x33) | ((n << 2) & 0xcc));
 259     n = (((n >> 4) & 0x0f) | ((n << 4) & 0xf0));
 260     return n;
 261 }
 262
 263 static int hamming_8_4( int a )
 264 {
 265     switch (a) {
 266     case 0xA8:
 267         return 0;
 268     case 0x0B:
 269         return 1;
 270     case 0x26:
 271         return 2;
 272     case 0x85:
 273         return 3;
 274     case 0x92:
 275         return 4;
 276     case 0x31:
 277         return 5;
 278     case 0x1C:
 279         return 6;
 280     case 0xBF:
 281         return 7;
 282     case 0x40:
 283         return 8;
 284     case 0xE3:
 285         return 9;
 286     case 0xCE:
 287         return 10;
 288     case 0x6D:
 289         return 11;
 290     case 0x7A:
 291         return 12;
 292     case 0xD9:
 293         return 13;
 294     case 0xF4:
 295         return 14;
 296     case 0x57:
 297         return 15;
 298     default:
 299         return -1;     // decoding error , not yet corrected
 300     }
 301 }
 302
 303 // utc-2 --> utf-8
 304 // this is not a general function, but it's enough for what we do here
 305 // the result buffer need to be at least 4 bytes long
 306 static void to_utf8( char * res, uint16_t ch )
 307 {
 308     if( ch >= 0x80 )
 309     {
 310         if( ch >= 0x800 )
 311         {
 312             res[0] = (ch >> 12) | 0xE0;
 313             res[1] = ((ch >> 6) & 0x3F) | 0x80;
 314             res[2] = (ch & 0x3F) | 0x80;
 315             res[3] = 0;
 316         }
 317         else
 318         {
 319             res[0] = (ch >> 6) | 0xC0;
 320             res[1] = (ch & 0x3F) | 0x80;
 321             res[2] = 0;
 322         }
 323     }
 324     else
 325     {
 326         res[0] = ch;
 327         res[1] = 0;
 328     }
 329 }
 330
 331 static void decode_string( char * res, int res_len,
 332                            decoder_sys_t *p_sys, int magazine,
 333                            uint8_t * packet, int len )
 334 {
 335     char utf8[7];
 336     char * pt = res;
 337     int i;
 338
 339     for ( i = 0; i < len; i++ )
 340     {
 341         int in = bytereverse( packet[i] ) & 0x7f;
 342         uint16_t out = 32;
 343         size_t l;
 344
 345         switch ( in )
 346         {
 347         /* special national characters */
 348         case 0x23:
 349             out = p_sys->pi_active_national_set[magazine][0];
 350             break;
 351         case 0x24:
 352             out = p_sys->pi_active_national_set[magazine][1];
 353             break;
 354         case 0x40:
 355             out = p_sys->pi_active_national_set[magazine][2];
 356             break;
 357         case 0x5b:
 358             out = p_sys->pi_active_national_set[magazine][3];
 359             break;
 360         case 0x5c:
 361             out = p_sys->pi_active_national_set[magazine][4];
 362             break;
 363         case 0x5d:
 364             out = p_sys->pi_active_national_set[magazine][5];
 365             break;
 366         case 0x5e:
 367             out = p_sys->pi_active_national_set[magazine][6];
 368             break;
 369         case 0x5f:
 370             out = p_sys->pi_active_national_set[magazine][7];
 371             break;
 372         case 0x60:
 373             out = p_sys->pi_active_national_set[magazine][8];
 374             break;
 375         case 0x7b:
 376             out = p_sys->pi_active_national_set[magazine][9];
 377             break;
 378         case 0x7c:
 379             out = p_sys->pi_active_national_set[magazine][10];
 380             break;
 381         case 0x7d:
 382             out = p_sys->pi_active_national_set[magazine][11];
 383             break;
 384         case 0x7e:
 385             out = p_sys->pi_active_national_set[magazine][12];
 386             break;
 387
 388         /* some special control characters (empirical) */
 389         case 0x0d:
 390             /* apparently this starts a sequence that ends with 0xb 0xb */
 391             while ( i + 1 < len && (bytereverse( packet[i+1] ) & 0x7f) != 0x0b )
 392                 i++;
 393             i += 2;
 394             break;
 395             /* goto skip; */
 396
 397         default:
 398             /* non documented national range 0x08 - 0x0f */
 399             if ( in >= 0x08 && in <= 0x0f )
 400             {
 401                 out = p_sys->pi_active_national_set[magazine][13 + in - 8];
 402                 break;
 403             }
 404
 405             /* normal ascii */
 406             if ( in > 32 && in < 0x7f )
 407                 out = in;
 408         }
 409
 410         /* handle undefined national characters */
 411         if ( out == 0 )
 412             out = 32;
 413
 414         /* convert to utf-8 */
 415         to_utf8( utf8, out );
 416         l = strlen( utf8 );
 417         if ( pt + l < res + res_len - 1 )
 418         {
 419             strcpy(pt, utf8);
 420             pt += l;
 421         }
 422
 423         /* skip: ; */
 424     }
 425     /* end: */
 426     *pt++ = 0;
 427 }
 428
 429 /*****************************************************************************
 430  * Decode:
 431  *****************************************************************************/
 432 static subpicture_t *Decode( decoder_t *p_dec, block_t **pp_block )
 433 {
 434     decoder_sys_t *p_sys = p_dec->p_sys;
 435     block_t       *p_block;
 436     subpicture_t  *p_spu = NULL;
 437     video_format_t fmt;
 438     /* int erase = 0; */
 439     int len, offset;
 440 #if 0
 441     int i_wanted_magazine = i_conf_wanted_page / 100;
 442     int i_wanted_page = 0x10 * ((i_conf_wanted_page % 100) / 10)
 443                          | (i_conf_wanted_page % 10);
 444 #endif
 445     bool b_update = false;
 446     char psz_text[512], *pt = psz_text;
 447     char psz_line[256];
 448     int i, total;
 449
 450     if( pp_block == NULL || *pp_block == NULL )
 451         return NULL;
 452     p_block = *pp_block;
 453     *pp_block = NULL;
 454
 455     dbg((p_dec, "start of telx packet with header %2x\n",
 456                 * (uint8_t *) p_block->p_buffer));
 457     len = p_block->i_buffer;
 458     for ( offset = 1; offset + 46 <= len; offset += 46 )
 459     {
 460         uint8_t * packet = (uint8_t *) p_block->p_buffer+offset;
 461 //        int vbi = ((0x20 & packet[2]) != 0 ? 0 : 313) + (0x1F & packet[2]);
 462
 463 //        dbg((p_dec, "vbi %d header %02x %02x %02x\n", vbi, packet[0], packet[1], packet[2]));
 464         if ( packet[0] == 0xFF ) continue;
 465
 466 /*      if (packet[1] != 0x2C) { */
 467 /*         printf("wrong header\n"); */
 468 /*         //goto error; */
 469 /*         continue; */
 470 /*       } */
 471
 472         int mpag = (hamming_8_4( packet[4] ) << 4) | hamming_8_4( packet[5] );
 473         int row, magazine;
 474         if ( mpag < 0 )
 475         {
 476             /* decode error */
 477             dbg((p_dec, "mpag hamming error\n"));
 478             continue;
 479         }
 480
 481         row = 0xFF & bytereverse(mpag);
 482         magazine = (7 & row) == 0 ? 8 : (7 & row);
 483         row >>= 3;
 484
 485         if ( p_sys->i_wanted_page != -1
 486               && magazine != p_sys->i_wanted_magazine )
 487             continue;
 488
 489         if ( row == 0 )
 490         {
 491             /* row 0 : flags and header line */
 492             int flag = 0;
 493             int a;
 494
 495             for ( a = 0; a < 6; a++ )
 496             {
 497                 flag |= (0xF & (bytereverse( hamming_8_4(packet[8 + a]) ) >> 4))
 498                           << (a * 4);
 499             }
 500
 501     /*         if (!p_sys->b_ignore_sub_flag && !(1 & flag>>15)) */
 502     /*           continue; */
 503
 504             p_sys->i_page[magazine] = (0xF0 & bytereverse( hamming_8_4(packet[7]) )) |
 505                              (0xF & (bytereverse( hamming_8_4(packet[6]) ) >> 4) );
 506
 507             decode_string( psz_line, sizeof(psz_line), p_sys, magazine,
 508                            packet + 14, 40 - 14 );
 509
 510             dbg((p_dec, "mag %d flags %x page %x character set %d subtitles %d", magazine, flag,
 511                  p_sys->i_page[magazine],
 512                  7 & flag>>21, 1 & flag>>15, psz_line));
 513
 514             p_sys->pi_active_national_set[magazine] =
 515                                  ppi_national_subsets[7 & (flag >> 21)];
 516
 517             p_sys->b_is_subtitle[magazine] = p_sys->b_ignore_sub_flag
 518                                               || ( (1 & (flag >> 15))
 519                                                   && (1 & (flag>>16)) );
 520
 521             dbg(( p_dec, "FLAGS%s%s%s%s%s%s%s mag_ser %d",
 522                   (1 & (flag>>14))? " news" : "",
 523                   (1 & (flag>>15))? " subtitle" : "",
 524                   (1 & (flag>>7))? " erase" : "",
 525                   (1 & (flag>>16))? " suppressed_head" : "",
 526                   (1 & (flag>>17))? " update" : "",
 527                   (1 & (flag>>18))? " interrupt" : "",
 528                   (1 & (flag>>19))? " inhibit" : "",
 529                   (1 & (flag>>20)) ));
 530
 531             if ( (p_sys->i_wanted_page != -1
 532                    && p_sys->i_page[magazine] != p_sys->i_wanted_page)
 533                    || !p_sys->b_is_subtitle[magazine] )
 534                 continue;
 535
 536             p_sys->b_erase[magazine] = (1 & (flag >> 7));
 537
 538             dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts, (long int)(p_sys->prev_pts+1500000)));
 539             /* kludge here :
 540              * we ignore the erase flag if it happens less than 1.5 seconds
 541              * before last caption
 542              * TODO   make this time configurable
 543              * UPDATE the kludge seems to be no more necessary
 544              *        so it's commented out*/
 545             if ( /*p_block->i_pts > p_sys->prev_pts + 1500000 && */
 546                  p_sys->b_erase[magazine] )
 547             {
 548                 int i;
 549
 550                 dbg((p_dec, "ERASE !\n"));
 551
 552                 p_sys->b_erase[magazine] = 0;
 553                 for ( i = 1; i < 32; i++ )
 554                 {
 555                     if ( !p_sys->ppsz_lines[i][0] ) continue;
 556                     /* b_update = true; */
 557                     p_sys->ppsz_lines[i][0] = 0;
 558                 }
 559             }
 560
 561             /* replace the row if it's different */
 562             if ( strcmp(psz_line, p_sys->ppsz_lines[row]) )
 563             {
 564                 strncpy( p_sys->ppsz_lines[row], psz_line,
 565                          sizeof(p_sys->ppsz_lines[row]) - 1);
 566             }
 567             b_update = true;
 568
 569         }
 570         else if ( row < 24 )
 571         {
 572             char * t;
 573             int i;
 574             /* row 1-23 : normal lines */
 575
 576             if ( (p_sys->i_wanted_page != -1
 577                    && p_sys->i_page[magazine] != p_sys->i_wanted_page)
 578                    || !p_sys->b_is_subtitle[magazine]
 579                    || (p_sys->i_wanted_page == -1
 580                         && p_sys->i_page[magazine] > 0x99) )
 581                 continue;
 582
 583             decode_string( psz_line, sizeof(psz_line), p_sys, magazine,
 584                            packet + 6, 40 );
 585             t = psz_line;
 586
 587             /* remove starting spaces */
 588             while ( *t == 32 ) t++;
 589
 590             /* remove trailing spaces */
 591             for ( i = strlen(t) - 1; i >= 0 && t[i] == 32; i-- );
 592             t[i + 1] = 0;
 593
 594             /* replace the row if it's different */
 595             if ( strcmp( t, p_sys->ppsz_lines[row] ) )
 596             {
 597                 strncpy( p_sys->ppsz_lines[row], t,
 598                          sizeof(p_sys->ppsz_lines[row]) - 1 );
 599                 b_update = true;
 600             }
 601
 602             if (t[0])
 603                 p_sys->prev_pts = p_block->i_pts;
 604
 605             dbg((p_dec, "%d %d : ", magazine, row));
 606             dbg((p_dec, "%s\n", t));
 607
 608 #ifdef TELX_DEBUG
 609             {
 610                 char dbg[256];
 611                 dbg[0] = 0;
 612                 for ( i = 0; i < 40; i++ )
 613                 {
 614                     int in = bytereverse(packet[6 + i]) & 0x7f;
 615                     sprintf(dbg + strlen(dbg), "%02x ", in);
 616                 }
 617                 dbg((p_dec, "%s\n", dbg));
 618                 dbg[0] = 0;
 619                 for ( i = 0; i < 40; i++ )
 620                 {
 621                     decode_string( psz_line, sizeof(psz_line), p_sys, magazine,
 622                                    packet + 6 + i, 1 );
 623                     sprintf( dbg + strlen(dbg), "%s  ", psz_line );
 624                 }
 625                 dbg((p_dec, "%s\n", dbg));
 626             }
 627 #endif
 628         }
 629         else if ( row == 25 )
 630         {
 631             /* row 25 : alternate header line */
 632             if ( (p_sys->i_wanted_page != -1
 633                    && p_sys->i_page[magazine] != p_sys->i_wanted_page)
 634                    || !p_sys->b_is_subtitle[magazine] )
 635                 continue;
 636
 637             decode_string( psz_line, sizeof(psz_line), p_sys, magazine,
 638                            packet + 6, 40 );
 639
 640             /* replace the row if it's different */
 641             if ( strcmp( psz_line, p_sys->ppsz_lines[0] ) )
 642             {
 643                 strncpy( p_sys->ppsz_lines[0], psz_line,
 644                          sizeof(p_sys->ppsz_lines[0]) - 1 );
 645                 /* b_update = true; */
 646             }
 647         }
 648 /*       else if (row == 26) { */
 649 /*         // row 26 : TV listings */
 650 /*       } else */
 651 /*         dbg((p_dec, "%d %d : %s\n", magazine, row, decode_string(p_sys, magazine, packet+6, 40))); */
 652     }
 653
 654     if ( !b_update )
 655         goto error;
 656
 657     total = 0;
 658     for ( i = 1; i < 24; i++ )
 659     {
 660         size_t l = strlen( p_sys->ppsz_lines[i] );
 661
 662         if ( l > sizeof(psz_text) - total - 1 )
 663             l = sizeof(psz_text) - total - 1;
 664
 665         if ( l > 0 )
 666         {
 667             memcpy( pt, p_sys->ppsz_lines[i], l );
 668             total += l;
 669             pt += l;
 670             if ( sizeof(psz_text) - total - 1 > 0 )
 671             {
 672                 *pt++ = '\n';
 673                 total++;
 674             }
 675         }
 676     }
 677     *pt = 0;
 678
 679     if ( !strcmp(psz_text, p_sys->psz_prev_text) )
 680         goto error;
 681
 682     dbg((p_dec, "UPDATE TELETEXT PICTURE\n"));
 683
 684     assert( sizeof(p_sys->psz_prev_text) >= sizeof(psz_text) );
 685     strcpy( p_sys->psz_prev_text, psz_text );
 686
 687     /* Create the subpicture unit */
 688     p_spu = decoder_NewSubpicture( p_dec, NULL );
 689     if( !p_spu )
 690     {
 691         msg_Warn( p_dec, "can't get spu buffer" );
 692         goto error;
 693     }
 694
 695     /* Create a new subpicture region */
 696     memset( &fmt, 0, sizeof(video_format_t) );
 697     fmt.i_chroma = VLC_CODEC_TEXT;
 698     fmt.i_width = fmt.i_height = 0;
 699     fmt.i_x_offset = fmt.i_y_offset = 0;
 700     p_spu->p_region = subpicture_region_New( &fmt );
 701     if( p_spu->p_region == NULL )
 702     {
 703         msg_Err( p_dec, "cannot allocate SPU region" );
 704         goto error;
 705     }
 706
 707     /* Normal text subs, easy markup */
 708     p_spu->p_region->i_align = SUBPICTURE_ALIGN_BOTTOM | p_sys->i_align;
 709     p_spu->p_region->i_x = p_sys->i_align ? 20 : 0;
 710     p_spu->p_region->i_y = 10;
 711     p_spu->p_region->psz_text = strdup(psz_text);
 712
 713     p_spu->i_start = p_block->i_pts;
 714     p_spu->i_stop = p_block->i_pts + p_block->i_length;
 715     p_spu->b_ephemer = (p_block->i_length == 0);
 716     p_spu->b_absolute = false;
 717     dbg((p_dec, "%ld --> %ld\n", (long int) p_block->i_pts/100000, (long int)p_block->i_length/100000));
 718
 719     block_Release( p_block );
 720     return p_spu;
 721
 722 error:
 723     if ( p_spu != NULL )
 724     {
 725         decoder_DeleteSubpicture( p_dec, p_spu );
 726         p_spu = NULL;
 727     }
 728
 729     block_Release( p_block );
 730     return NULL;
 731 }