git.sesse.net Git - vlc/blob - modules/codec/subtitles/subsdec.c

   1 /*****************************************************************************
   2  * subsdec.c : text subtitles decoder
   3  *****************************************************************************
   4  * Copyright (C) 2000-2006 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@videolan.org>
   8  *          Samuel Hocevar <sam@zoy.org>
   9  *          Derk-Jan Hartman <hartman at videolan dot org>
  10  *          Bernie Purcell <bitmap@videolan.org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30 #ifdef HAVE_CONFIG_H
  31 # include "config.h"
  32 #endif
  33
  34 #include "subsdec.h"
  35 #include <vlc_plugin.h>
  36
  37 /*****************************************************************************
  38  * Local prototypes
  39  *****************************************************************************/
  40 static int  OpenDecoder   ( vlc_object_t * );
  41 static void CloseDecoder  ( vlc_object_t * );
  42
  43 static subpicture_t   *DecodeBlock   ( decoder_t *, block_t ** );
  44 static subpicture_t   *ParseText     ( decoder_t *, block_t * );
  45 static char           *StripTags      ( char * );
  46 static char           *CreateHtmlSubtitle ( char * );
  47
  48
  49 /*****************************************************************************
  50  * Module descriptor.
  51  *****************************************************************************/
  52 static const char *ppsz_encodings[] = { DEFAULT_NAME, "ASCII", "UTF-8", "",
  53     "ISO-8859-1", "CP1252", "MacRoman", "MacIceland","ISO-8859-15", "",
  54     "ISO-8859-2", "CP1250", "MacCentralEurope", "MacCroatian", "MacRomania", "",
  55     "ISO-8859-5", "CP1251", "MacCyrillic", "MacUkraine", "KOI8-R", "KOI8-U", "KOI8-RU", "",
  56     "ISO-8859-6", "CP1256", "MacArabic", "",
  57     "ISO-8859-7", "CP1253", "MacGreek", "",
  58     "ISO-8859-8", "CP1255", "MacHebrew", "",
  59     "ISO-8859-9", "CP1254", "MacTurkish", "",
  60     "ISO-8859-13", "CP1257", "",
  61     "ISO-2022-JP", "ISO-2022-JP-1", "ISO-2022-JP-2", "EUC-JP", "SHIFT_JIS", "",
  62     "ISO-2022-CN", "ISO-2022-CN-EXT", "EUC-CN", "EUC-TW", "BIG5", "BIG5-HKSCS", "",
  63     "ISO-2022-KR", "EUC-KR", "",
  64     "MacThai", "KOI8-T", "",
  65     "ISO-8859-3", "ISO-8859-4", "ISO-8859-10", "ISO-8859-14", "ISO-8859-16", "",
  66     "CP850", "CP862", "CP866", "CP874", "CP932", "CP949", "CP950", "CP1133", "CP1258", "",
  67     "Macintosh", "",
  68     "UTF-7", "UTF-16", "UTF-16BE", "UTF-16LE", "UTF-32", "UTF-32BE", "UTF-32LE",
  69     "C99", "JAVA", "UCS-2", "UCS-2BE", "UCS-2LE", "UCS-4", "UCS-4BE", "UCS-4LE", "",
  70     "HZ", "GBK", "GB18030", "JOHAB", "ARMSCII-8",
  71     "Georgian-Academy", "Georgian-PS", "TIS-620", "MuleLao-1", "VISCII", "TCVN",
  72     "HPROMAN8", "NEXTSTEP" };
  73 /*
  74 SSA supports charset selection.
  75 The following known charsets are used:
  76
  77 0 = Ansi - Western European
  78 1 = default
  79 2 = symbol
  80 3 = invalid
  81 77 = Mac
  82 128 = Japanese (Shift JIS)
  83 129 = Hangul
  84 130 = Johab
  85 134 = GB2312 Simplified Chinese
  86 136 = Big5 Traditional Chinese
  87 161 = Greek
  88 162 = Turkish
  89 163 = Vietnamese
  90 177 = Hebrew
  91 178 = Arabic
  92 186 = Baltic
  93 204 = Russian (Cyrillic)
  94 222 = Thai
  95 238 = Eastern European
  96 254 = PC 437
  97 */
  98
  99 static int  pi_justification[] = { 0, 1, 2 };
 100 static const char *ppsz_justification_text[] = {N_("Center"),N_("Left"),N_("Right")};
 101
 102 #define ENCODING_TEXT N_("Subtitles text encoding")
 103 #define ENCODING_LONGTEXT N_("Set the encoding used in text subtitles")
 104 #define ALIGN_TEXT N_("Subtitles justification")
 105 #define ALIGN_LONGTEXT N_("Set the justification of subtitles")
 106 #define AUTODETECT_UTF8_TEXT N_("UTF-8 subtitles autodetection")
 107 #define AUTODETECT_UTF8_LONGTEXT N_("This enables automatic detection of " \
 108             "UTF-8 encoding within subtitles files.")
 109 #define FORMAT_TEXT N_("Formatted Subtitles")
 110 #define FORMAT_LONGTEXT N_("Some subtitle formats allow for text formatting. " \
 111  "VLC partly implements this, but you can choose to disable all formatting.")
 112
 113
 114 vlc_module_begin();
 115     set_shortname( _("Subtitles"));
 116     set_description( _("Text subtitles decoder") );
 117     set_capability( "decoder", 50 );
 118     set_callbacks( OpenDecoder, CloseDecoder );
 119     set_category( CAT_INPUT );
 120     set_subcategory( SUBCAT_INPUT_SCODEC );
 121
 122     add_integer( "subsdec-align", 0, NULL, ALIGN_TEXT, ALIGN_LONGTEXT,
 123                  false );
 124         change_integer_list( pi_justification, ppsz_justification_text, 0 );
 125     add_string( "subsdec-encoding", DEFAULT_NAME, NULL,
 126                 ENCODING_TEXT, ENCODING_LONGTEXT, false );
 127         change_string_list( ppsz_encodings, 0, 0 );
 128     add_bool( "subsdec-autodetect-utf8", true, NULL,
 129               AUTODETECT_UTF8_TEXT, AUTODETECT_UTF8_LONGTEXT, false );
 130     add_bool( "subsdec-formatted", true, NULL, FORMAT_TEXT, FORMAT_LONGTEXT,
 131                  false );
 132 vlc_module_end();
 133
 134 /*****************************************************************************
 135  * OpenDecoder: probe the decoder and return score
 136  *****************************************************************************
 137  * Tries to launch a decoder and return score so that the interface is able
 138  * to chose.
 139  *****************************************************************************/
 140 static int OpenDecoder( vlc_object_t *p_this )
 141 {
 142     decoder_t     *p_dec = (decoder_t*)p_this;
 143     decoder_sys_t *p_sys;
 144     vlc_value_t    val;
 145
 146     switch( p_dec->fmt_in.i_codec )
 147     {
 148         case VLC_FOURCC('s','u','b','t'):
 149         case VLC_FOURCC('s','s','a',' '):
 150         case VLC_FOURCC('t','1','4','0'):
 151             break;
 152         default:
 153             return VLC_EGENERIC;
 154     }
 155
 156     p_dec->pf_decode_sub = DecodeBlock;
 157
 158     /* Allocate the memory needed to store the decoder's structure */
 159     p_dec->p_sys = p_sys = malloc( sizeof( *p_sys ) );
 160     if( p_sys == NULL )
 161     {
 162         msg_Err( p_dec, "out of memory" );
 163         return VLC_ENOMEM;
 164     }
 165
 166     /* init of p_sys */
 167     memset( p_sys, 0, sizeof( *p_sys ) );
 168     p_sys->i_align = 0;
 169     p_sys->iconv_handle = (vlc_iconv_t)-1;
 170     p_sys->b_autodetect_utf8 = false;
 171     p_sys->b_ass = false;
 172     p_sys->i_original_height = -1;
 173     p_sys->i_original_width = -1;
 174     TAB_INIT( p_sys->i_ssa_styles, p_sys->pp_ssa_styles );
 175     TAB_INIT( p_sys->i_images, p_sys->pp_images );
 176
 177     char *psz_charset = NULL;
 178
 179     /* First try demux-specified encoding */
 180     if( p_dec->fmt_in.i_codec == VLC_FOURCC('t','1','4','0') )
 181         psz_charset = strdup( "UTF-8" ); /* IUT T.140 is always using UTF-8 */
 182     else
 183     if( p_dec->fmt_in.subs.psz_encoding && *p_dec->fmt_in.subs.psz_encoding )
 184     {
 185         psz_charset = strdup (p_dec->fmt_in.subs.psz_encoding);
 186         msg_Dbg (p_dec, "trying demuxer-specified character encoding: %s",
 187                  p_dec->fmt_in.subs.psz_encoding ?: "not specified");
 188     }
 189
 190     /* Second, try configured encoding */
 191     if (psz_charset == NULL)
 192     {
 193         psz_charset = var_CreateGetNonEmptyString (p_dec, "subsdec-encoding");
 194         if ((psz_charset != NULL) && !strcasecmp (psz_charset, DEFAULT_NAME))
 195         {
 196             free (psz_charset);
 197             psz_charset = NULL;
 198         }
 199
 200         msg_Dbg (p_dec, "trying configured character encoding: %s",
 201                  psz_charset ?: "not specified");
 202     }
 203
 204     /* Third, try "local" encoding with optional UTF-8 autodetection */
 205     if (psz_charset == NULL)
 206     {
 207         psz_charset = strdup (GetFallbackEncoding ());
 208         msg_Dbg (p_dec, "trying default character encoding: %s",
 209                  psz_charset ?: "not specified");
 210
 211         if (var_CreateGetBool (p_dec, "subsdec-autodetect-utf8"))
 212         {
 213             msg_Dbg (p_dec, "using automatic UTF-8 detection");
 214             p_sys->b_autodetect_utf8 = true;
 215         }
 216     }
 217
 218     /* Forth, don't do character decoding, i.e. assume UTF-8 */
 219     if (psz_charset == NULL)
 220     {
 221         psz_charset = strdup ("UTF-8");
 222         msg_Dbg (p_dec, "using UTF-8 character encoding" );
 223     }
 224
 225     if ((psz_charset != NULL)
 226      && strcasecmp (psz_charset, "UTF-8")
 227      && strcasecmp (psz_charset, "utf8"))
 228     {
 229         p_sys->iconv_handle = vlc_iconv_open ("UTF-8", psz_charset);
 230         if (p_sys->iconv_handle == (vlc_iconv_t)(-1))
 231             msg_Err (p_dec, "cannot convert from %s: %m", psz_charset);
 232     }
 233     free (psz_charset);
 234
 235     var_Create( p_dec, "subsdec-align", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
 236     var_Get( p_dec, "subsdec-align", &val );
 237     p_sys->i_align = val.i_int;
 238
 239     if( p_dec->fmt_in.i_codec == VLC_FOURCC('s','s','a',' ')
 240      && var_CreateGetBool( p_dec, "subsdec-formatted" ) )
 241     {
 242         if( p_dec->fmt_in.i_extra > 0 )
 243             ParseSSAHeader( p_dec );
 244     }
 245
 246     return VLC_SUCCESS;
 247 }
 248
 249 /****************************************************************************
 250  * DecodeBlock: the whole thing
 251  ****************************************************************************
 252  * This function must be fed with complete subtitles units.
 253  ****************************************************************************/
 254 static subpicture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 255 {
 256     subpicture_t *p_spu = NULL;
 257
 258     if( !pp_block || *pp_block == NULL ) return NULL;
 259
 260     p_spu = ParseText( p_dec, *pp_block );
 261
 262     block_Release( *pp_block );
 263     *pp_block = NULL;
 264
 265     return p_spu;
 266 }
 267
 268 /*****************************************************************************
 269  * CloseDecoder: clean up the decoder
 270  *****************************************************************************/
 271 static void CloseDecoder( vlc_object_t *p_this )
 272 {
 273     decoder_t *p_dec = (decoder_t *)p_this;
 274     decoder_sys_t *p_sys = p_dec->p_sys;
 275
 276     if( p_sys->iconv_handle != (vlc_iconv_t)-1 )
 277         vlc_iconv_close( p_sys->iconv_handle );
 278
 279     if( p_sys->pp_ssa_styles )
 280     {
 281         int i;
 282         for( i = 0; i < p_sys->i_ssa_styles; i++ )
 283         {
 284             if( !p_sys->pp_ssa_styles[i] )
 285                 continue;
 286
 287             free( p_sys->pp_ssa_styles[i]->psz_stylename );
 288             free( p_sys->pp_ssa_styles[i]->font_style.psz_fontname );
 289             free( p_sys->pp_ssa_styles[i] );
 290         }
 291         TAB_CLEAN( p_sys->i_ssa_styles, p_sys->pp_ssa_styles );
 292     }
 293     if( p_sys->pp_images )
 294     {
 295         int i;
 296         for( i = 0; i < p_sys->i_images; i++ )
 297         {
 298             if( !p_sys->pp_images[i] )
 299                 continue;
 300
 301             if( p_sys->pp_images[i]->p_pic )
 302                 p_sys->pp_images[i]->p_pic->pf_release( p_sys->pp_images[i]->p_pic );
 303             free( p_sys->pp_images[i]->psz_filename );
 304
 305             free( p_sys->pp_images[i] );
 306         }
 307         TAB_CLEAN( p_sys->i_images, p_sys->pp_images );
 308     }
 309
 310     free( p_sys );
 311 }
 312
 313 /*****************************************************************************
 314  * ParseText: parse an text subtitle packet and send it to the video output
 315  *****************************************************************************/
 316 static subpicture_t *ParseText( decoder_t *p_dec, block_t *p_block )
 317 {
 318     decoder_sys_t *p_sys = p_dec->p_sys;
 319     subpicture_t *p_spu = NULL;
 320     char *psz_subtitle = NULL;
 321     video_format_t fmt;
 322
 323     /* We cannot display a subpicture with no date */
 324     if( p_block->i_pts == 0 )
 325     {
 326         msg_Warn( p_dec, "subtitle without a date" );
 327         return NULL;
 328     }
 329
 330     /* Check validity of packet data */
 331     /* An "empty" line containing only \0 can be used to force
 332        and ephemer picture from the screen */
 333     if( p_block->i_buffer < 1 )
 334     {
 335         msg_Warn( p_dec, "no subtitle data" );
 336         return NULL;
 337     }
 338
 339     /* Should be resiliant against bad subtitles */
 340     psz_subtitle = strndup( (const char *)p_block->p_buffer,
 341                             p_block->i_buffer );
 342     if( psz_subtitle == NULL )
 343         return NULL;
 344
 345     if( p_sys->iconv_handle == (vlc_iconv_t)-1 )
 346     {
 347         if (EnsureUTF8( psz_subtitle ) == NULL)
 348         {
 349             msg_Err( p_dec, _("failed to convert subtitle encoding.\n"
 350                      "Try manually setting a character-encoding "
 351                      "before you open the file.") );
 352         }
 353     }
 354     else
 355     {
 356
 357         if( p_sys->b_autodetect_utf8 )
 358         {
 359             if( IsUTF8( psz_subtitle ) == NULL )
 360             {
 361                 msg_Dbg( p_dec, "invalid UTF-8 sequence: "
 362                          "disabling UTF-8 subtitles autodetection" );
 363                 p_sys->b_autodetect_utf8 = false;
 364             }
 365         }
 366
 367         if( !p_sys->b_autodetect_utf8 )
 368         {
 369             size_t inbytes_left = strlen( psz_subtitle );
 370             size_t outbytes_left = 6 * inbytes_left;
 371             char *psz_new_subtitle = malloc( outbytes_left + 1 );
 372             char *psz_convert_buffer_out = psz_new_subtitle;
 373             const char *psz_convert_buffer_in = psz_subtitle;
 374
 375             size_t ret = vlc_iconv( p_sys->iconv_handle,
 376                                     &psz_convert_buffer_in, &inbytes_left,
 377                                     &psz_convert_buffer_out, &outbytes_left );
 378
 379             *psz_convert_buffer_out++ = '\0';
 380             free( psz_subtitle );
 381
 382             if( ( ret == (size_t)(-1) ) || inbytes_left )
 383             {
 384                 free( psz_new_subtitle );
 385                 msg_Err( p_dec, _("failed to convert subtitle encoding.\n"
 386                         "Try manually setting a character-encoding "
 387                                 "before you open the file.") );
 388                 return NULL;
 389             }
 390
 391             psz_subtitle = realloc( psz_new_subtitle,
 392                                     psz_convert_buffer_out - psz_new_subtitle );
 393         }
 394     }
 395
 396     /* Create the subpicture unit */
 397     p_spu = p_dec->pf_spu_buffer_new( p_dec );
 398     if( !p_spu )
 399     {
 400         msg_Warn( p_dec, "can't get spu buffer" );
 401         free( psz_subtitle );
 402         return NULL;
 403     }
 404
 405     p_spu->b_pausable = true;
 406
 407     /* Create a new subpicture region */
 408     memset( &fmt, 0, sizeof(video_format_t) );
 409     fmt.i_chroma = VLC_FOURCC('T','E','X','T');
 410     fmt.i_aspect = 0;
 411     fmt.i_width = fmt.i_height = 0;
 412     fmt.i_x_offset = fmt.i_y_offset = 0;
 413     p_spu->p_region = p_spu->pf_create_region( VLC_OBJECT(p_dec), &fmt );
 414     if( !p_spu->p_region )
 415     {
 416         msg_Err( p_dec, "cannot allocate SPU region" );
 417         free( psz_subtitle );
 418         p_dec->pf_spu_buffer_del( p_dec, p_spu );
 419         return NULL;
 420     }
 421
 422     /* Decode and format the subpicture unit */
 423     if( p_dec->fmt_in.i_codec != VLC_FOURCC('s','s','a',' ') )
 424     {
 425         /* Normal text subs, easy markup */
 426         p_spu->p_region->i_align = SUBPICTURE_ALIGN_BOTTOM | p_sys->i_align;
 427         p_spu->i_x = p_sys->i_align ? 20 : 0;
 428         p_spu->i_y = 10;
 429
 430         /* Remove formatting from string */
 431
 432         p_spu->p_region->psz_text = StripTags( psz_subtitle );
 433         if( var_CreateGetBool( p_dec, "subsdec-formatted" ) )
 434         {
 435             p_spu->p_region->psz_html = CreateHtmlSubtitle( psz_subtitle );
 436         }
 437
 438         p_spu->i_start = p_block->i_pts;
 439         p_spu->i_stop = p_block->i_pts + p_block->i_length;
 440         p_spu->b_ephemer = (p_block->i_length == 0);
 441         p_spu->b_absolute = false;
 442     }
 443     else
 444     {
 445         /* Decode SSA/USF strings */
 446         if( p_dec->fmt_in.i_codec == VLC_FOURCC('s','s','a',' ') )
 447             ParseSSAString( p_dec, psz_subtitle, p_spu );
 448
 449         p_spu->i_start = p_block->i_pts;
 450         p_spu->i_stop = p_block->i_pts + p_block->i_length;
 451         p_spu->b_ephemer = (p_block->i_length == 0);
 452         p_spu->b_absolute = false;
 453         p_spu->i_original_picture_width = p_sys->i_original_width;
 454         p_spu->i_original_picture_height = p_sys->i_original_height;
 455     }
 456     free( psz_subtitle );
 457
 458     return p_spu;
 459 }
 460
 461 char* GotoNextLine( char *psz_text )
 462 {
 463     char *p_newline = psz_text;
 464
 465     while( p_newline[0] != '\0' )
 466     {
 467         if( p_newline[0] == '\n' || p_newline[0] == '\r' )
 468         {
 469             p_newline++;
 470             while( p_newline[0] == '\n' || p_newline[0] == '\r' )
 471                 p_newline++;
 472             break;
 473         }
 474         else p_newline++;
 475     }
 476     return p_newline;
 477 }
 478
 479 /* Function now handles tags with attribute values, and tries
 480  * to deal with &' commands too. It no longer modifies the string
 481  * in place, so that the original text can be reused
 482  */
 483 static char *StripTags( char *psz_subtitle )
 484 {
 485     char *psz_text_start;
 486     char *psz_text;
 487
 488     psz_text = psz_text_start = malloc( strlen( psz_subtitle ) + 1 );
 489     if( !psz_text_start )
 490         return NULL;
 491
 492     while( *psz_subtitle )
 493     {
 494         if( *psz_subtitle == '<' )
 495         {
 496             if( strncasecmp( psz_subtitle, "<br/>", 5 ) == 0 )
 497                 *psz_text++ = '\n';
 498
 499             psz_subtitle += strcspn( psz_subtitle, ">" );
 500         }
 501         else if( *psz_subtitle == '&' )
 502         {
 503             if( !strncasecmp( psz_subtitle, "&lt;", 4 ))
 504             {
 505                 *psz_text++ = '<';
 506                 psz_subtitle += strcspn( psz_subtitle, ";" );
 507             }
 508             else if( !strncasecmp( psz_subtitle, "&gt;", 4 ))
 509             {
 510                 *psz_text++ = '>';
 511                 psz_subtitle += strcspn( psz_subtitle, ";" );
 512             }
 513             else if( !strncasecmp( psz_subtitle, "&amp;", 5 ))
 514             {
 515                 *psz_text++ = '&';
 516                 psz_subtitle += strcspn( psz_subtitle, ";" );
 517             }
 518             else if( !strncasecmp( psz_subtitle, "&quot;", 6 ))
 519             {
 520                 *psz_text++ = '\"';
 521                 psz_subtitle += strcspn( psz_subtitle, ";" );
 522             }
 523             else
 524             {
 525                 /* Assume it is just a normal ampersand */
 526                 *psz_text++ = '&';
 527             }
 528         }
 529         else
 530         {
 531             *psz_text++ = *psz_subtitle;
 532         }
 533
 534         psz_subtitle++;
 535     }
 536     *psz_text = '\0';
 537     psz_text_start = realloc( psz_text_start, strlen( psz_text_start ) + 1 );
 538
 539     return psz_text_start;
 540 }
 541
 542 /* Try to respect any style tags present in the subtitle string. The main
 543  * problem here is a lack of adequate specs for the subtitle formats.
 544  * SSA/ASS and USF are both detail spec'ed -- but they are handled elsewhere.
 545  * SAMI has a detailed spec, but extensive rework is needed in the demux
 546  * code to prevent all this style information being excised, as it presently
 547  * does.
 548  * That leaves the others - none of which were (I guess) originally intended
 549  * to be carrying style information. Over time people have used them that way.
 550  * In the absence of specifications from which to work, the tags supported
 551  * have been restricted to the simple set permitted by the USF DTD, ie. :
 552  *  Basic: <br>, <i>, <b>, <u>
 553  *  Extended: <font>
 554  *    Attributes: face
 555  *                family
 556  *                size
 557  *                color
 558  *                outline-color
 559  *                shadow-color
 560  *                outline-level
 561  *                shadow-level
 562  *                back-color
 563  *                alpha
 564  * There is also the further restriction that the subtitle be well-formed
 565  * as an XML entity, ie. the HTML sentence:
 566  *        <b><i>Bold and Italics</b></i>
 567  * doesn't qualify because the tags aren't nested one inside the other.
 568  * <text> tags are automatically added to the output to ensure
 569  * well-formedness.
 570  * If the text doesn't qualify for any reason, a NULL string is
 571  * returned, and the rendering engine will fall back to the
 572  * plain text version of the subtitle.
 573  */
 574 static char *CreateHtmlSubtitle( char *psz_subtitle )
 575 {
 576     char   *psz_tag = malloc( ( strlen( psz_subtitle ) / 3 ) + 1 );
 577     if( !psz_tag ) return NULL;
 578     size_t  i_buf_size     = strlen( psz_subtitle ) + 100;
 579     char   *psz_html_start = malloc( i_buf_size );
 580
 581     psz_tag[ 0 ] = '\0';
 582
 583     if( psz_html_start != NULL )
 584     {
 585         char *psz_html = psz_html_start;
 586
 587         strcpy( psz_html, "<text>" );
 588         psz_html += 6;
 589
 590         while( *psz_subtitle )
 591         {
 592             if( *psz_subtitle == '\n' )
 593             {
 594                 strcpy( psz_html, "<br/>" );
 595                 psz_html += 5;
 596                 psz_subtitle++;
 597             }
 598             else if( *psz_subtitle == '<' )
 599             {
 600                 if( !strncasecmp( psz_subtitle, "<br/>", 5 ))
 601                 {
 602                     strcpy( psz_html, "<br/>" );
 603                     psz_html += 5;
 604                     psz_subtitle += 5;
 605                 }
 606                 else if( !strncasecmp( psz_subtitle, "<b>", 3 ) )
 607                 {
 608                     strcpy( psz_html, "<b>" );
 609                     strcat( psz_tag, "b" );
 610                     psz_html += 3;
 611                     psz_subtitle += 3;
 612                 }
 613                 else if( !strncasecmp( psz_subtitle, "<i>", 3 ) )
 614                 {
 615                     strcpy( psz_html, "<i>" );
 616                     strcat( psz_tag, "i" );
 617                     psz_html += 3;
 618                     psz_subtitle += 3;
 619                 }
 620                 else if( !strncasecmp( psz_subtitle, "<u>", 3 ) )
 621                 {
 622                     strcpy( psz_html, "<u>" );
 623                     strcat( psz_tag, "u" );
 624                     psz_html += 3;
 625                     psz_subtitle += 3;
 626                 }
 627                 else if( !strncasecmp( psz_subtitle, "<font ", 6 ))
 628                 {
 629                     const char *psz_attribs[] = { "face=\"", "family=\"", "size=\"",
 630                             "color=\"", "outline-color=\"", "shadow-color=\"",
 631                             "outline-level=\"", "shadow-level=\"", "back-color=\"",
 632                             "alpha=\"", NULL };
 633
 634                     strcpy( psz_html, "<font " );
 635                     strcat( psz_tag, "f" );
 636                     psz_html += 6;
 637                     psz_subtitle += 6;
 638
 639                     while( *psz_subtitle != '>' )
 640                     {
 641                         int  k;
 642
 643                         for( k=0; psz_attribs[ k ]; k++ )
 644                         {
 645                             int i_len = strlen( psz_attribs[ k ] );
 646
 647                             if( !strncasecmp( psz_subtitle, psz_attribs[ k ], i_len ))
 648                             {
 649                                 i_len += strcspn( psz_subtitle + i_len, "\"" ) + 1;
 650
 651                                 strncpy( psz_html, psz_subtitle, i_len );
 652                                 psz_html += i_len;
 653                                 psz_subtitle += i_len;
 654                                 break;
 655                             }
 656                         }
 657                         if( psz_attribs[ k ] == NULL )
 658                         {
 659                             /* Jump over unrecognised tag */
 660                             int i_len = strcspn( psz_subtitle, "\"" ) + 1;
 661
 662                             i_len += strcspn( psz_subtitle + i_len, "\"" ) + 1;
 663                             psz_subtitle += i_len;
 664                         }
 665                         while (*psz_subtitle == ' ')
 666                             *psz_html++ = *psz_subtitle++;
 667                     }
 668                     *psz_html++ = *psz_subtitle++;
 669                 }
 670                 else if( !strncmp( psz_subtitle, "</", 2 ))
 671                 {
 672                     bool  b_match     = false;
 673                     int         i_len       = strlen( psz_tag ) - 1;
 674                     char       *psz_lastTag = NULL;
 675
 676                     if( i_len >= 0 )
 677                     {
 678                         psz_lastTag = psz_tag + i_len;
 679                         i_len = 0;
 680
 681                         switch( *psz_lastTag )
 682                         {
 683                             case 'b':
 684                                 b_match = !strncasecmp( psz_subtitle, "</b>", 4 );
 685                                 i_len   = 4;
 686                                 break;
 687                             case 'i':
 688                                 b_match = !strncasecmp( psz_subtitle, "</i>", 4 );
 689                                 i_len   = 4;
 690                                 break;
 691                             case 'u':
 692                                 b_match = !strncasecmp( psz_subtitle, "</u>", 4 );
 693                                 i_len   = 4;
 694                                 break;
 695                             case 'f':
 696                                 b_match = !strncasecmp( psz_subtitle, "</font>", 7 );
 697                                 i_len   = 7;
 698                                 break;
 699                         }
 700                     }
 701                     if( ! b_match )
 702                     {
 703                         /* Not well formed -- kill everything */
 704                         free( psz_html_start );
 705                         psz_html_start = NULL;
 706                         break;
 707                     }
 708                     *psz_lastTag = '\0';
 709                     strncpy( psz_html, psz_subtitle, i_len );
 710                     psz_html += i_len;
 711                     psz_subtitle += i_len;
 712                 }
 713                 else
 714                 {
 715                     psz_subtitle += strcspn( psz_subtitle, ">" );
 716                 }
 717             }
 718             else if( *psz_subtitle == '&' )
 719             {
 720                 if( !strncasecmp( psz_subtitle, "&lt;", 4 ))
 721                 {
 722                     strcpy( psz_html, "&lt;" );
 723                     psz_html += 4;
 724                     psz_subtitle += 4;
 725                 }
 726                 else if( !strncasecmp( psz_subtitle, "&gt;", 4 ))
 727                 {
 728                     strcpy( psz_html, "&gt;" );
 729                     psz_html += 4;
 730                     psz_subtitle += 4;
 731                 }
 732                 else if( !strncasecmp( psz_subtitle, "&amp;", 5 ))
 733                 {
 734                     strcpy( psz_html, "&amp;" );
 735                     psz_html += 5;
 736                     psz_subtitle += 5;
 737                 }
 738                 else
 739                 {
 740                     strcpy( psz_html, "&amp;" );
 741                     psz_html += 5;
 742                     psz_subtitle++;
 743                 }
 744             }
 745             else
 746             {
 747                 *psz_html = *psz_subtitle;
 748                 if( psz_html > psz_html_start )
 749                 {
 750                     /* Check for double whitespace */
 751                     if((( *psz_html == ' ' ) ||
 752                         ( *psz_html == '\t' )) &&
 753                        (( *(psz_html-1) == ' ' ) ||
 754                         ( *(psz_html-1) == '\t' )))
 755                     {
 756                         strcpy( psz_html, NO_BREAKING_SPACE );
 757                         psz_html += strlen( NO_BREAKING_SPACE ) - 1;
 758                     }
 759                 }
 760                 psz_html++;
 761                 psz_subtitle++;
 762             }
 763
 764             if( ( size_t )( psz_html - psz_html_start ) > i_buf_size - 10 )
 765             {
 766                 int i_len = psz_html - psz_html_start;
 767
 768                 i_buf_size += 100;
 769                 psz_html_start = realloc( psz_html_start, i_buf_size );
 770                 psz_html = psz_html_start + i_len;
 771                 *psz_html = '\0';
 772             }
 773         }
 774         strcpy( psz_html, "</text>" );
 775         psz_html += 7;
 776
 777         if( psz_tag[ 0 ] != '\0' )
 778         {
 779             /* Not well formed -- kill everything */
 780             free( psz_html_start );
 781             psz_html_start = NULL;
 782         }
 783         else if( psz_html_start )
 784         {
 785             /* Shrink the memory requirements */
 786             psz_html_start = realloc( psz_html_start,  psz_html - psz_html_start + 1 );
 787         }
 788     }
 789     free( psz_tag );
 790     return psz_html_start;
 791 }