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