git.sesse.net Git - vlc/blob - modules/video_filter/subsdelay.c

   1 /*****************************************************************************
   2  * subsdelay.c : Subsdelay plugin for vlc
   3  *****************************************************************************
   4  * Copyright © 2011 VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Yuval Tze <yuvaltze@gmail.com>
   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 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_filter.h>
  35 #include <vlc_subpicture.h>
  36 #include <vlc_es.h>
  37 #include <stdlib.h>
  38
  39 /*****************************************************************************
  40  * Local constants
  41  *****************************************************************************/
  42
  43 /* descriptions */
  44
  45 #define SUBSDELAY_HELP N_("Change subtitle delay")
  46
  47 #define MODE_TEXT N_( "Delay calculation mode" )
  48 #define MODE_LONGTEXT N_( \
  49     "Absolute delay - add absolute delay to each subtitle. " \
  50     "Relative to source delay - multiply subtitle delay. " \
  51     "Relative to source content - determine subtitle delay from its content (text)." )
  52
  53 #define FACTOR_TEXT N_( "Calculation factor" )
  54 #define FACTOR_LONGTEXT N_( "Calculation factor. " \
  55     "In Absolute delay mode the factor represents seconds.")
  56
  57 #define OVERLAP_TEXT N_( "Maximum overlapping subtitles" )
  58 #define OVERLAP_LONGTEXT N_( "Maximum number of subtitles allowed at the same time." )
  59
  60 #define MIN_ALPHA_TEXT N_( "Minimum alpha value" )
  61 #define MIN_ALPHA_LONGTEXT N_( \
  62     "Alpha value of the earliest subtitle, where 0 is fully transparent and 255 is fully opaque." )
  63
  64 #define MIN_STOPS_INTERVAL_TEXT N_( "Interval between two disappearances" )
  65 #define MIN_STOPS_INTERVAL_LONGTEXT N_( \
  66     "Minimum time (in milliseconds) that subtitle should stay after its predecessor has disappeared " \
  67     "(subtitle delay will be extended to meet this requirement)." )
  68
  69 #define MIN_STOP_START_INTERVAL_TEXT N_( "Interval between disappearance and appearance" )
  70 #define MIN_STOP_START_INTERVAL_LONGTEXT N_( \
  71     "Minimum time (in milliseconds) between subtitle disappearance and newer subtitle appearance " \
  72     "(earlier subtitle delay will be extended to fill the gap)." )
  73
  74 #define MIN_START_STOP_INTERVAL_TEXT N_( "Interval between appearance and disappearance" )
  75 #define MIN_START_STOP_INTERVAL_LONGTEXT N_( \
  76     "Minimum time (in milliseconds) that subtitle should stay after newer subtitle has appeared " \
  77     "(earlier subtitle delay will be shortened to avoid the overlap)." )
  78
  79 static const int pi_mode_values[] = { 0, 1, 2 };
  80 static const char * const ppsz_mode_descriptions[] = { N_( "Absolute delay" ), N_( "Relative to source delay" ), N_(
  81         "Relative to source content" ) };
  82
  83 /* parameters */
  84
  85 #define CFG_PREFIX "subsdelay-"
  86
  87 #define CFG_MODE                    CFG_PREFIX "mode"
  88 #define CFG_FACTOR                  CFG_PREFIX "factor"
  89 #define CFG_OVERLAP                 CFG_PREFIX "overlap"
  90
  91 #define CFG_MIN_ALPHA               CFG_PREFIX "min-alpha"
  92 #define CFG_MIN_STOPS_INTERVAL      CFG_PREFIX "min-stops"
  93 #define CFG_MIN_STOP_START_INTERVAL CFG_PREFIX "min-stop-start"
  94 #define CFG_MIN_START_STOP_INTERVAL CFG_PREFIX "min-start-stop"
  95
  96
  97 /* max subtitles handled on the heap */
  98 #define SUBSDELAY_MAX_ENTRIES 16
  99
 100 /* factor convert macros */
 101 #define INT_FACTOR_BASE                  1000
 102 #define FLOAT_FACTOR_TO_INT_FACTOR( x )  (int)( ( x ) * INT_FACTOR_BASE )
 103 #define INT_FACTOR_TO_MICROSEC( x )      ( ( x ) * ( 1000000 / INT_FACTOR_BASE ) )
 104 #define INT_FACTOR_TO_RANK_FACTOR( x )   ( x )
 105 #define MILLISEC_TO_MICROSEC( x )        ( ( x ) * 1000 )
 106
 107
 108 #define SUBSDELAY_MODE_ABSOLUTE                0
 109 #define SUBSDELAY_MODE_RELATIVE_SOURCE_DELAY   1
 110 #define SUBSDELAY_MODE_RELATIVE_SOURCE_CONTENT 2
 111
 112
 113 /*****************************************************************************
 114  * subsdelay_heap_entry_t: Heap entry
 115  *****************************************************************************/
 116
 117 typedef subpicture_updater_sys_t subsdelay_heap_entry_t;
 118
 119 struct subpicture_updater_sys_t
 120 {
 121     subpicture_t *p_subpic; /* local subtitle */
 122
 123     subpicture_t *p_source; /* subtitle source */
 124
 125     filter_t *p_filter; /* assigned subsdelay filter */
 126
 127     subsdelay_heap_entry_t *p_next; /* next entry */
 128
 129     bool b_update_stop; /* new stop value should be calculated */
 130
 131     bool b_update_ephemer; /* actual stop value is unknown */
 132
 133     bool b_update_position; /* subtitle position should be updated */
 134
 135     bool b_check_empty; /* subtitle content should be checked */
 136
 137     mtime_t i_new_stop; /* new stop value */
 138
 139     /* last region data*/
 140
 141     int i_last_region_x;
 142
 143     int i_last_region_y;
 144
 145     int i_last_region_align;
 146
 147     bool b_last_region_saved;
 148 };
 149
 150 /*****************************************************************************
 151  * subsdelay_heap_t: Heap
 152  *****************************************************************************/
 153
 154 typedef struct
 155 {
 156     vlc_mutex_t lock; /* heap global lock */
 157
 158     subsdelay_heap_entry_t *p_list[SUBSDELAY_MAX_ENTRIES]; /* subtitles entries array */
 159
 160     subsdelay_heap_entry_t *p_head; /* subtitles entries linked list */
 161
 162     int i_count; /* subtitles count */
 163
 164 } subsdelay_heap_t;
 165
 166
 167
 168 /*****************************************************************************
 169 * filter_sys_t: Subsdelay filter descriptor
 170  *****************************************************************************/
 171
 172 struct filter_sys_t
 173 {
 174     int i_mode; /* delay calculation mode */
 175
 176     int i_factor; /* calculation factor */
 177
 178     int i_overlap; /* max overlap */
 179
 180     int i_min_alpha; /* oldest subtitle alpha value */
 181
 182     int64_t i_min_stops_interval;
 183
 184     int64_t i_min_stop_start_interval;
 185
 186     int64_t i_min_start_stop_interval;
 187
 188     subsdelay_heap_t heap; /* subpictures list */
 189 };
 190
 191
 192 /*****************************************************************************
 193  * Filter functions
 194  *****************************************************************************/
 195
 196 static int SubsdelayCreate( vlc_object_t * );
 197
 198 static void SubsdelayDestroy( vlc_object_t * );
 199
 200 static subpicture_t * SubsdelayFilter( filter_t *p_filter, subpicture_t* p_subpic );
 201
 202 static int SubsdelayCallback( vlc_object_t *p_this, char const *psz_var, vlc_value_t oldval, vlc_value_t newval,
 203         void *p_data );
 204
 205 /*****************************************************************************
 206  * Helper functions
 207  *****************************************************************************/
 208
 209 static void SubsdelayEnforceDelayRules( filter_t *p_filter );
 210
 211 static int64_t SubsdelayEstimateDelay( filter_t *p_filter, subsdelay_heap_entry_t *p_entry );
 212
 213 static void SubsdelayRecalculateDelays( filter_t *p_filter );
 214
 215 static int SubsdelayCalculateAlpha( filter_t *p_filter, int i_overlapping, int i_source_alpha );
 216
 217 static int SubsdelayGetTextRank( char *psz_text );
 218
 219 static bool SubsdelayIsTextEmpty( char *psz_text );
 220
 221 /*****************************************************************************
 222  * Subpicture functions
 223  *****************************************************************************/
 224
 225 static int SubpicValidateWrapper( subpicture_t *p_subpic, bool has_src_changed, const video_format_t *p_fmt_src,
 226                                   bool has_dst_changed, const video_format_t *p_fmt_dst, mtime_t i_ts );
 227
 228 static void SubpicUpdateWrapper( subpicture_t *p_subpic, const video_format_t *p_fmt_src,
 229                                   const video_format_t *p_fmt_dst, mtime_t i_ts );
 230
 231 static void SubpicDestroyWrapper( subpicture_t *p_subpic );
 232
 233 static void SubpicLocalUpdate( subpicture_t* p_subpic, mtime_t i_ts );
 234
 235 static bool SubpicIsEmpty( subpicture_t* p_subpic );
 236
 237 static subpicture_t *SubpicClone( subpicture_t *p_source, subpicture_updater_t *updater );
 238
 239 static void SubpicDestroyClone( subpicture_t *p_subpic );
 240
 241 /*****************************************************************************
 242  * Heap functions
 243  *****************************************************************************/
 244
 245 static void SubsdelayHeapInit( subsdelay_heap_t *p_heap );
 246
 247 static void SubsdelayHeapDestroy( subsdelay_heap_t *p_heap );
 248
 249 static subsdelay_heap_entry_t *SubsdelayHeapPush( subsdelay_heap_t *p_heap, subpicture_t *p_subpic, filter_t *p_filter );
 250
 251 static void SubsdelayHeapRemove( subsdelay_heap_t *p_heap, subsdelay_heap_entry_t *p_entry );
 252
 253 static void SubsdelayRebuildList( subsdelay_heap_t *p_heap );
 254
 255 static void SubsdelayHeapLock( subsdelay_heap_t *p_heap );
 256
 257 static void SubsdelayHeapUnlock( subsdelay_heap_t *p_heap );
 258
 259 static subsdelay_heap_entry_t * SubsdelayEntryCreate( subpicture_t *p_subpic, filter_t *p_filter );
 260
 261 static void SubsdelayEntryDestroy( subsdelay_heap_entry_t *p_entry );
 262
 263 /* heap / entries special functionality */
 264
 265 static int SubsdelayHeapCountOverlap( subsdelay_heap_t *p_heap, subsdelay_heap_entry_t *p_entry, mtime_t i_date );
 266
 267 static void SubsdelayEntryNewStopValueUpdated( subsdelay_heap_entry_t *p_entry );
 268
 269 /*****************************************************************************
 270  * Module descriptor
 271  *****************************************************************************/
 272
 273 vlc_module_begin()
 274         set_shortname( _("Subsdelay") )
 275         set_description( _("Subtitle delay") )
 276         set_help( SUBSDELAY_HELP )
 277         set_capability( "sub filter", 0 )
 278         set_callbacks( SubsdelayCreate, SubsdelayDestroy )
 279         set_category( CAT_VIDEO )
 280         set_subcategory( SUBCAT_VIDEO_SUBPIC )
 281
 282         add_integer( CFG_MODE, 1, MODE_TEXT, MODE_LONGTEXT, false )
 283         change_integer_list( pi_mode_values, ppsz_mode_descriptions )
 284
 285         add_float_with_range( CFG_FACTOR, 2, 0, 20, FACTOR_TEXT, FACTOR_LONGTEXT, false )
 286
 287         add_integer_with_range( CFG_OVERLAP, 3, 1, 4, OVERLAP_TEXT, OVERLAP_LONGTEXT, false )
 288
 289         add_integer_with_range( CFG_MIN_ALPHA, 70, 0, 255, MIN_ALPHA_TEXT, MIN_ALPHA_LONGTEXT, false )
 290
 291         set_section( N_("Overlap fix"), NULL )
 292
 293         add_integer( CFG_MIN_STOPS_INTERVAL, 1000, MIN_STOPS_INTERVAL_TEXT, MIN_STOPS_INTERVAL_LONGTEXT, false )
 294
 295         add_integer( CFG_MIN_START_STOP_INTERVAL, 1000, MIN_START_STOP_INTERVAL_TEXT,
 296                      MIN_START_STOP_INTERVAL_LONGTEXT, false )
 297
 298         add_integer( CFG_MIN_STOP_START_INTERVAL, 1000, MIN_STOP_START_INTERVAL_TEXT,
 299                      MIN_STOP_START_INTERVAL_LONGTEXT, false )
 300
 301     vlc_module_end ()
 302
 303 static const char * const ppsz_filter_options[] = { "mode", "factor", "overlap", NULL };
 304
 305 /*****************************************************************************
 306  * SubsdelayCreate: Create subsdelay filter
 307  *****************************************************************************/
 308 static int SubsdelayCreate( vlc_object_t *p_this )
 309 {
 310     filter_t *p_filter = (filter_t *) p_this;
 311     filter_sys_t *p_sys;
 312
 313     /* allocate structure */
 314     p_sys = (filter_sys_t*) malloc( sizeof(filter_sys_t) );
 315
 316     if( !p_sys )
 317     {
 318         return VLC_ENOMEM;
 319     }
 320
 321     /* init parameters */
 322
 323     p_sys->i_mode = var_CreateGetIntegerCommand( p_filter, CFG_MODE );
 324     var_AddCallback( p_filter, CFG_MODE, SubsdelayCallback, p_sys );
 325
 326     p_sys->i_factor = FLOAT_FACTOR_TO_INT_FACTOR( var_CreateGetFloatCommand( p_filter, CFG_FACTOR ) );
 327     var_AddCallback( p_filter, CFG_FACTOR, SubsdelayCallback, p_sys );
 328
 329     p_sys->i_overlap = var_CreateGetIntegerCommand( p_filter, CFG_OVERLAP );
 330     var_AddCallback( p_filter, CFG_OVERLAP, SubsdelayCallback, p_sys );
 331
 332     p_sys->i_min_alpha = var_CreateGetIntegerCommand( p_filter, CFG_MIN_ALPHA );
 333     var_AddCallback( p_filter, CFG_MIN_ALPHA, SubsdelayCallback, p_sys );
 334
 335     p_sys->i_min_stops_interval
 336             = MILLISEC_TO_MICROSEC( var_CreateGetIntegerCommand( p_filter, CFG_MIN_STOPS_INTERVAL ) );
 337     var_AddCallback( p_filter, CFG_MIN_STOPS_INTERVAL, SubsdelayCallback, p_sys );
 338
 339     p_sys->i_min_stop_start_interval
 340             = MILLISEC_TO_MICROSEC( var_CreateGetIntegerCommand( p_filter, CFG_MIN_STOP_START_INTERVAL ) );
 341     var_AddCallback( p_filter, CFG_MIN_STOP_START_INTERVAL, SubsdelayCallback, p_sys );
 342
 343     p_sys->i_min_start_stop_interval
 344             = MILLISEC_TO_MICROSEC( var_CreateGetIntegerCommand( p_filter, CFG_MIN_START_STOP_INTERVAL ) );
 345     var_AddCallback( p_filter, CFG_MIN_START_STOP_INTERVAL, SubsdelayCallback, p_sys );
 346
 347     p_filter->p_sys = p_sys;
 348     p_filter->pf_sub_filter = SubsdelayFilter;
 349
 350     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options, p_filter->p_cfg );
 351
 352     SubsdelayHeapInit( &p_sys->heap );
 353
 354     return VLC_SUCCESS;
 355 }
 356
 357 /*****************************************************************************
 358  * SubsdelayDestroy: Destroy subsdelay filter
 359  *****************************************************************************/
 360 static void SubsdelayDestroy( vlc_object_t *p_this )
 361 {
 362     filter_t *p_filter = (filter_t *) p_this;
 363     filter_sys_t *p_sys = p_filter->p_sys;
 364
 365     SubsdelayHeapDestroy( &p_sys->heap );
 366
 367     /* destroy parameters */
 368
 369     var_DelCallback( p_filter, CFG_MODE, SubsdelayCallback, p_sys );
 370     var_Destroy( p_filter, CFG_MODE );
 371
 372     var_DelCallback( p_filter, CFG_FACTOR, SubsdelayCallback, p_sys );
 373     var_Destroy( p_filter, CFG_FACTOR );
 374
 375     var_DelCallback( p_filter, CFG_OVERLAP, SubsdelayCallback, p_sys );
 376     var_Destroy( p_filter, CFG_OVERLAP );
 377
 378     var_DelCallback( p_filter, CFG_MIN_ALPHA, SubsdelayCallback, p_sys );
 379     var_Destroy( p_filter, CFG_MIN_ALPHA );
 380
 381     var_DelCallback( p_filter, CFG_MIN_STOPS_INTERVAL, SubsdelayCallback, p_sys );
 382     var_Destroy( p_filter, CFG_MIN_STOPS_INTERVAL );
 383
 384     var_DelCallback( p_filter, CFG_MIN_STOP_START_INTERVAL, SubsdelayCallback, p_sys );
 385     var_Destroy( p_filter, CFG_MIN_STOP_START_INTERVAL );
 386
 387     var_DelCallback( p_filter, CFG_MIN_START_STOP_INTERVAL, SubsdelayCallback, p_sys );
 388     var_Destroy( p_filter, CFG_MIN_START_STOP_INTERVAL );
 389
 390     free( p_sys );
 391 }
 392
 393 /*****************************************************************************
 394  * SubsdelayFilter: Filter new subpicture
 395  *****************************************************************************/
 396 static subpicture_t * SubsdelayFilter( filter_t *p_filter, subpicture_t* p_subpic )
 397 {
 398     subsdelay_heap_t *p_heap;
 399     subsdelay_heap_entry_t *p_entry;
 400
 401     if( !p_subpic->b_subtitle )
 402     {
 403         return p_subpic;
 404     }
 405
 406     if( SubpicIsEmpty( p_subpic ) )
 407     {
 408         /* empty subtitles usually helps terminate ephemer subtitles, but this filter calculates the stop value anyway,
 409            so this subtitle can be dropped */
 410
 411         subpicture_Delete( p_subpic );
 412
 413         return NULL;
 414     }
 415
 416     p_heap = &p_filter->p_sys->heap;
 417
 418     /* add subpicture to the heap */
 419
 420     SubsdelayHeapLock( p_heap );
 421
 422     p_entry = SubsdelayHeapPush( p_heap, p_subpic, p_filter );
 423     if( !p_entry )
 424     {
 425         SubsdelayHeapUnlock( p_heap );
 426
 427         msg_Err(p_filter, "Can't add subpicture to the heap");
 428
 429         return p_subpic;
 430     }
 431
 432     p_subpic = p_entry->p_subpic; /* get the local subpic */
 433
 434     if( p_subpic->b_ephemer )
 435     {
 436         /* set a relativly long delay in hope that the next subtitle
 437            will arrive in this time and the real delay could be determined */
 438
 439         p_subpic->i_stop = p_subpic->i_start + 20000000; /* start + 20 sec */
 440         p_subpic->b_ephemer = false;
 441     }
 442
 443
 444     SubsdelayEnforceDelayRules( p_filter );
 445
 446     SubsdelayHeapUnlock( p_heap );
 447
 448     return p_subpic;
 449 }
 450
 451 /*****************************************************************************
 452  * SubsdelayCallback: Subsdelay parameters callback
 453  *****************************************************************************/
 454 static int SubsdelayCallback( vlc_object_t *p_this, char const *psz_var, vlc_value_t oldval, vlc_value_t newval,
 455         void *p_data )
 456 {
 457     filter_sys_t *p_sys = (filter_sys_t *) p_data;
 458
 459     VLC_UNUSED( oldval );
 460
 461     SubsdelayHeapLock( &p_sys->heap );
 462
 463     if( !strcmp( psz_var, CFG_MODE ) )
 464     {
 465         p_sys->i_mode = newval.i_int;
 466     }
 467     else if( !strcmp( psz_var, CFG_FACTOR ) )
 468     {
 469         p_sys->i_factor = FLOAT_FACTOR_TO_INT_FACTOR( newval.f_float );
 470     }
 471     else if( !strcmp( psz_var, CFG_OVERLAP ) )
 472     {
 473         p_sys->i_overlap = newval.i_int;
 474     }
 475     else if( !strcmp( psz_var, CFG_MIN_ALPHA ) )
 476     {
 477         p_sys->i_min_alpha = newval.i_int;
 478     }
 479     else if( !strcmp( psz_var, CFG_MIN_STOPS_INTERVAL ) )
 480     {
 481         p_sys->i_min_stops_interval = MILLISEC_TO_MICROSEC( newval.i_int );
 482     }
 483     else if( !strcmp( psz_var, CFG_MIN_STOP_START_INTERVAL ) )
 484     {
 485         p_sys->i_min_stop_start_interval = MILLISEC_TO_MICROSEC( newval.i_int );
 486     }
 487     else if( !strcmp( psz_var, CFG_MIN_START_STOP_INTERVAL ) )
 488     {
 489         p_sys->i_min_start_stop_interval = MILLISEC_TO_MICROSEC( newval.i_int );
 490     }
 491     else
 492     {
 493         SubsdelayHeapUnlock( &p_sys->heap );
 494         return VLC_ENOVAR;
 495     }
 496
 497     SubsdelayRecalculateDelays( (filter_t *) p_this );
 498
 499     SubsdelayHeapUnlock( &p_sys->heap );
 500     return VLC_SUCCESS;
 501 }
 502
 503 /*****************************************************************************
 504  * SubsdelayHeapInit: Initialize heap
 505  *****************************************************************************/
 506 static void SubsdelayHeapInit( subsdelay_heap_t *p_heap )
 507 {
 508     p_heap->i_count = 0;
 509     p_heap->p_head = NULL;
 510
 511     vlc_mutex_init( &p_heap->lock );
 512 }
 513
 514 /*****************************************************************************
 515  * SubsdelayHeapDestroy: Destroy the heap and remove its entries
 516  *****************************************************************************/
 517 static void SubsdelayHeapDestroy( subsdelay_heap_t *p_heap )
 518 {
 519     subsdelay_heap_entry_t *p_entry;
 520
 521     SubsdelayHeapLock( p_heap );
 522
 523     for( p_entry = p_heap->p_head; p_entry != NULL; p_entry = p_entry->p_next )
 524     {
 525         p_entry->p_subpic->i_stop = p_entry->p_source->i_stop;
 526
 527         p_entry->p_filter = NULL;
 528     }
 529
 530     SubsdelayHeapUnlock( p_heap );
 531
 532     vlc_mutex_destroy( &p_heap->lock );
 533 }
 534
 535 /*****************************************************************************
 536  * SubsdelayHeapPush: Add new subpicture to the heap
 537  *****************************************************************************/
 538 static subsdelay_heap_entry_t *SubsdelayHeapPush( subsdelay_heap_t *p_heap, subpicture_t *p_subpic, filter_t *p_filter )
 539 {
 540     subsdelay_heap_entry_t *p_entry, *p_last, *p_new_entry;
 541
 542     if( p_heap->i_count >= SUBSDELAY_MAX_ENTRIES )
 543     {
 544         return NULL; /* the heap is full */
 545     }
 546
 547     p_new_entry = SubsdelayEntryCreate( p_subpic, p_filter );
 548
 549     if( !p_new_entry )
 550     {
 551         return NULL;
 552     }
 553
 554
 555     p_last = NULL;
 556
 557     for( p_entry = p_heap->p_head; p_entry != NULL; p_entry = p_entry->p_next )
 558     {
 559         if( p_entry->p_source->i_start > p_subpic->i_start )
 560         {
 561             /* the new entry should be inserted before p_entry */
 562             break;
 563         }
 564
 565         p_last = p_entry;
 566     }
 567
 568     if( p_last )
 569     {
 570         p_new_entry->p_next = p_last->p_next;
 571         p_last->p_next = p_new_entry;
 572
 573
 574         if( p_last->b_update_ephemer )
 575         {
 576             /* the correct stop value can be determined */
 577
 578             p_last->p_source->i_stop = p_new_entry->p_source->i_start;
 579             p_last->b_update_ephemer = false;
 580         }
 581     }
 582     else
 583     {
 584         p_new_entry->p_next = p_heap->p_head;
 585         p_heap->p_head = p_new_entry;
 586     }
 587
 588
 589     /* rebuild list */
 590
 591     SubsdelayRebuildList( p_heap );
 592
 593     return p_new_entry;
 594 }
 595
 596 /*****************************************************************************
 597  * SubsdelayHeapRemove: Remove entry
 598  *****************************************************************************/
 599 static void SubsdelayHeapRemove( subsdelay_heap_t *p_heap, subsdelay_heap_entry_t *p_entry )
 600 {
 601     subsdelay_heap_entry_t *p_curr, *p_prev;
 602
 603     p_prev = NULL;
 604
 605     for( p_curr = p_heap->p_head; p_curr != NULL; p_curr = p_curr->p_next )
 606     {
 607         if( p_curr == p_entry )
 608         {
 609             break;
 610         }
 611
 612         p_prev = p_curr;
 613     }
 614
 615     if( p_prev )
 616     {
 617         p_prev->p_next = p_entry->p_next;
 618     }
 619     else
 620     {
 621         p_heap->p_head = p_entry->p_next;
 622     }
 623
 624     p_entry->p_filter = NULL;
 625
 626     SubsdelayRebuildList( p_heap );
 627 }
 628
 629
 630 static void SubsdelayRebuildList( subsdelay_heap_t *p_heap )
 631 {
 632     subsdelay_heap_entry_t *p_curr;
 633     int i_index;
 634
 635     i_index = 0;
 636     for( p_curr = p_heap->p_head; p_curr != NULL; p_curr = p_curr->p_next )
 637     {
 638         p_heap->p_list[i_index] = p_curr;
 639         i_index++;
 640     }
 641
 642     p_heap->i_count = i_index;
 643 }
 644
 645 /*****************************************************************************
 646  * SubsdelayHeapLock: Lock the heap
 647  *****************************************************************************/
 648 static void SubsdelayHeapLock( subsdelay_heap_t *p_heap )
 649 {
 650     vlc_mutex_lock( &p_heap->lock );
 651 }
 652
 653 /*****************************************************************************
 654  * SubsdelayHeapUnlock: Unlock the heap
 655  *****************************************************************************/
 656 static void SubsdelayHeapUnlock( subsdelay_heap_t *p_heap )
 657 {
 658     vlc_mutex_unlock( &p_heap->lock );
 659 }
 660
 661
 662 /*****************************************************************************
 663  * SubsdelayHeapCreateEntry: Create new entry
 664  *****************************************************************************/
 665 static subsdelay_heap_entry_t * SubsdelayEntryCreate( subpicture_t *p_source, filter_t *p_filter )
 666 {
 667     subsdelay_heap_entry_t *p_entry;
 668
 669     subpicture_t *p_new_subpic;
 670
 671     subpicture_updater_t updater;
 672
 673     /* allocate structure */
 674
 675     p_entry = (subsdelay_heap_entry_t *) malloc( sizeof( subsdelay_heap_entry_t ) );
 676
 677     if( !p_entry )
 678     {
 679         return NULL;
 680     }
 681
 682     /* initialize local updater */
 683
 684     updater.p_sys = p_entry;
 685     updater.pf_validate = SubpicValidateWrapper;
 686     updater.pf_update = SubpicUpdateWrapper;
 687     updater.pf_destroy = SubpicDestroyWrapper;
 688
 689     /* create new subpic */
 690
 691     p_new_subpic = SubpicClone( p_source,  &updater );
 692
 693     if( !p_new_subpic )
 694     {
 695         free( p_entry );
 696         return NULL;
 697     }
 698
 699     /* initialize entry */
 700
 701     p_entry->p_subpic = p_new_subpic;
 702     p_entry->p_source = p_source;
 703     p_entry->p_filter = p_filter;
 704     p_entry->p_next = NULL;
 705     p_entry->b_update_stop = true;
 706     p_entry->b_update_ephemer = p_source->b_ephemer;
 707     p_entry->b_update_position = true;
 708     p_entry->b_check_empty = true;
 709     p_entry->i_new_stop = p_source->i_stop;
 710     p_entry->b_last_region_saved = false;
 711     p_entry->i_last_region_x = 0;
 712     p_entry->i_last_region_y = 0;
 713     p_entry->i_last_region_align = 0;
 714
 715     return p_entry;
 716 }
 717
 718 /*****************************************************************************
 719  * SubsdelayEntryDestroy: Destroy entry
 720  *****************************************************************************/
 721 static void SubsdelayEntryDestroy( subsdelay_heap_entry_t *p_entry )
 722 {
 723     SubpicDestroyClone( p_entry->p_source );
 724     free( p_entry );
 725 }
 726
 727 /*****************************************************************************
 728  * SubsdelayHeapCountOverlap: Count overlapping subtitles at a given time
 729  *****************************************************************************/
 730 static int SubsdelayHeapCountOverlap( subsdelay_heap_t *p_heap, subsdelay_heap_entry_t *p_entry, mtime_t i_date )
 731 {
 732     subsdelay_heap_entry_t *p_curr;
 733     int i_overlaps;
 734
 735     VLC_UNUSED( p_heap );
 736
 737     i_overlaps = 0;
 738
 739     for( p_curr = p_entry->p_next; p_curr != NULL; p_curr = p_curr->p_next )
 740     {
 741         if( p_curr->p_source->i_start > i_date )
 742         {
 743             break;
 744         }
 745
 746         if( !p_curr->b_check_empty ) /* subtitle was checked, and it's not empty */
 747         {
 748             i_overlaps++;
 749         }
 750     }
 751
 752     return i_overlaps;
 753 }
 754
 755 /*****************************************************************************
 756  * SubsdelayEntryNewStopValueUpdated: Update source stop value after the new
 757  *     stop value was changed
 758  *****************************************************************************/
 759 static void SubsdelayEntryNewStopValueUpdated( subsdelay_heap_entry_t *p_entry )
 760 {
 761     if( !p_entry->b_update_stop )
 762     {
 763         p_entry->p_subpic->i_stop = p_entry->i_new_stop - 100000; /* 0.1 sec less */
 764     }
 765 }
 766
 767 /*****************************************************************************
 768  * SubsdelayEnforceDelayRules: Update subtitles delay after adding new
 769  *     subtitle or changing subtitle stop value
 770  *****************************************************************************/
 771 static void SubsdelayEnforceDelayRules( filter_t *p_filter )
 772 {
 773     subsdelay_heap_entry_t ** p_list;
 774     int i, j, i_count, i_overlap;
 775     int64_t i_offset;
 776     int64_t i_min_stops_interval;
 777     int64_t i_min_stop_start_interval;
 778     int64_t i_min_start_stop_interval;
 779
 780     p_list = p_filter->p_sys->heap.p_list;
 781     i_count = p_filter->p_sys->heap.i_count;
 782
 783     i_overlap = p_filter->p_sys->i_overlap;
 784     i_min_stops_interval = p_filter->p_sys->i_min_stops_interval;
 785     i_min_stop_start_interval = p_filter->p_sys->i_min_stop_start_interval;
 786     i_min_start_stop_interval = p_filter->p_sys->i_min_start_stop_interval;
 787
 788     /* step 1 - enforce min stops interval rule (extend delays) */
 789
 790     /* look for:
 791     [subtitle 1 ..............]
 792            [subtitle 2 ..............]
 793                               |<-MinStopsInterval->|
 794
 795      * and extend newer subtitle:
 796     [subtitle 1 ..............]
 797            [subtitle 2 ............................]
 798                               |<-MinStopsInterval->|
 799     */
 800
 801     for( i = 0; i < i_count - 1; i++ )
 802     {
 803         p_list[i + 1]->i_new_stop = __MAX( p_list[i + 1]->i_new_stop,
 804                 p_list[i]->i_new_stop + i_min_stops_interval );
 805     }
 806
 807     /* step 2 - enforce min stop start interval rule (extend delays) */
 808
 809     /* look for:
 810     [subtitle 1 .........]
 811                                    [subtitle 2 ....]
 812           |<-MinStopStartInterval->|
 813
 814      * and fill the gap:
 815     [subtitle 1 ..................]
 816                                    [subtitle 2 ....]
 817           |<-MinStopStartInterval->|
 818     */
 819
 820     for( i = 0; i < i_count; i++ )
 821     {
 822         for( j = i + 1; j < __MIN( i_count, i + 1 + i_overlap ); j++ )
 823         {
 824             i_offset = p_list[j]->p_source->i_start - p_list[i]->i_new_stop;
 825
 826             if( i_offset <= 0 )
 827             {
 828                 continue;
 829             }
 830
 831             if( i_offset < i_min_stop_start_interval )
 832             {
 833                 p_list[i]->i_new_stop = p_list[j]->p_source->i_start;
 834             }
 835
 836             break;
 837         }
 838     }
 839
 840     /* step 3 - enforce min start stop interval rule (shorten delays) */
 841
 842     /* look for:
 843     [subtitle 1 ............]
 844                     [subtitle 2 ....................]
 845                     |<-MinStartStopInterval->|
 846
 847      * and remove the overlapping part:
 848     [subtitle 1 ...]
 849                     [subtitle 2 ....................]
 850                     |<-MinStartStopInterval->|
 851     */
 852
 853
 854     for( i = 0; i < i_count; i++ )
 855     {
 856         for( j = i + 1; j < __MIN( i_count, i + 1 + i_overlap ); j++ )
 857         {
 858             i_offset = p_list[i]->i_new_stop - p_list[j]->p_source->i_start;
 859
 860             if( i_offset <= 0 )
 861             {
 862                 break;
 863             }
 864
 865             if( i_offset < i_min_start_stop_interval )
 866             {
 867                 p_list[i]->i_new_stop = p_list[j]->p_source->i_start;
 868                 break;
 869             }
 870         }
 871     }
 872
 873     /* step 4 - enforce max overlapping rule (shorten delays)*/
 874
 875     /* look for: (overlap = 2)
 876     [subtitle 1 ..............]
 877              [subtitle 2 ..............]
 878                       [subtitle 3 ..............]
 879
 880
 881      * and cut older subtitle:
 882     [subtitle 1 .....]
 883              [subtitle 2 ..............]
 884                       [subtitle 3 ..............]
 885     */
 886
 887     for( i = 0; i < i_count - i_overlap; i++ )
 888     {
 889         if( p_list[i]->i_new_stop > p_list[i + i_overlap]->p_source->i_start )
 890         {
 891             p_list[i]->i_new_stop = p_list[i + i_overlap]->p_source->i_start;
 892         }
 893     }
 894
 895     /* finally - update all */
 896
 897     for( i = 0; i < i_count; i++ )
 898     {
 899         SubsdelayEntryNewStopValueUpdated( p_list[i] );
 900     }
 901 }
 902
 903 /*****************************************************************************
 904  * SubsdelayRecalculateDelays: Recalculate subtitles delay after changing
 905  *     one of the filter's parameters
 906  *****************************************************************************/
 907 static void SubsdelayRecalculateDelays( filter_t *p_filter )
 908 {
 909     subsdelay_heap_entry_t *p_curr;
 910
 911     for( p_curr = p_filter->p_sys->heap.p_head; p_curr != NULL; p_curr = p_curr->p_next )
 912     {
 913         if( !p_curr->b_update_ephemer )
 914         {
 915             p_curr->i_new_stop = p_curr->p_source->i_start + SubsdelayEstimateDelay( p_filter, p_curr );
 916             p_curr->b_update_stop = false;
 917         }
 918     }
 919
 920     SubsdelayEnforceDelayRules( p_filter );
 921 }
 922
 923 /*****************************************************************************
 924  * SubpicValidateWrapper: Subpicture validate callback wrapper
 925  *****************************************************************************/
 926 static int SubpicValidateWrapper( subpicture_t *p_subpic, bool has_src_changed, const video_format_t *p_fmt_src,
 927                                   bool has_dst_changed, const video_format_t *p_fmt_dst, mtime_t i_ts )
 928 {
 929     subsdelay_heap_entry_t *p_entry;
 930     mtime_t i_new_ts;
 931     int i_result = VLC_SUCCESS;
 932
 933     p_entry = p_subpic->updater.p_sys;
 934     if( !p_entry )
 935     {
 936         return VLC_SUCCESS;
 937     }
 938
 939     /* call source validate */
 940     if( p_entry->p_source->updater.pf_validate )
 941     {
 942         i_new_ts = p_entry->p_source->i_start +
 943                    ( (double)( p_entry->p_source->i_stop - p_entry->p_source->i_start ) * ( i_ts - p_entry->p_source->i_start ) ) /
 944                    ( p_entry->i_new_stop - p_entry->p_source->i_start );
 945
 946         i_result = p_entry->p_source->updater.pf_validate( p_entry->p_source, has_src_changed, p_fmt_src,
 947                                                         has_dst_changed, p_fmt_dst, i_new_ts );
 948     }
 949
 950
 951     p_entry->b_last_region_saved = false;
 952
 953     if( p_subpic->p_region )
 954     {
 955         /* save copy */
 956         p_entry->i_last_region_x = p_subpic->p_region->i_x;
 957         p_entry->i_last_region_y = p_subpic->p_region->i_y;
 958         p_entry->i_last_region_align = p_subpic->p_region->i_align;
 959
 960         p_entry->b_last_region_saved = true;
 961     }
 962
 963     if( !i_result )
 964     {
 965         /* subpic update isn't necessary, so local update should be called here */
 966         SubpicLocalUpdate( p_subpic, i_ts );
 967     }
 968
 969     return i_result;
 970 }
 971
 972 /*****************************************************************************
 973  * SubpicUpdateWrapper: Subpicture update callback wrapper
 974  *****************************************************************************/
 975 static void SubpicUpdateWrapper( subpicture_t *p_subpic, const video_format_t *p_fmt_src,
 976                                   const video_format_t *p_fmt_dst, mtime_t i_ts )
 977 {
 978     subsdelay_heap_entry_t *p_entry;
 979     mtime_t i_new_ts;
 980
 981     p_entry = p_subpic->updater.p_sys;
 982     if( !p_entry )
 983     {
 984         return;
 985     }
 986
 987     /* call source update */
 988     if( p_entry->p_source->updater.pf_update )
 989     {
 990         i_new_ts = p_entry->p_source->i_start +
 991                    ( (double)( p_entry->p_source->i_stop - p_entry->p_source->i_start ) * ( i_ts - p_entry->p_source->i_start ) ) /
 992                    ( p_entry->i_new_stop - p_entry->p_source->i_start );
 993
 994         p_entry->p_source->p_region = p_entry->p_subpic->p_region;
 995
 996         p_entry->p_source->updater.pf_update( p_entry->p_source, p_fmt_src, p_fmt_dst, i_new_ts );
 997
 998         p_entry->p_subpic->p_region = p_entry->p_source->p_region;
 999     }
1000
1001     SubpicLocalUpdate( p_subpic, i_ts );
1002 }
1003
1004 /*****************************************************************************
1005  * SubpicDestroyCallback: Subpicture destroy callback
1006  *****************************************************************************/
1007 static void SubpicDestroyWrapper( subpicture_t *p_subpic )
1008 {
1009     subsdelay_heap_entry_t *p_entry;
1010     subsdelay_heap_t *p_heap;
1011
1012     p_entry = p_subpic->updater.p_sys;
1013
1014     if( !p_entry )
1015     {
1016         return;
1017     }
1018
1019     if( p_entry->p_filter )
1020     {
1021         p_heap = &p_entry->p_filter->p_sys->heap;
1022
1023         SubsdelayHeapLock( p_heap );
1024         SubsdelayHeapRemove( p_heap, p_entry );
1025         SubsdelayHeapUnlock( p_heap );
1026     }
1027
1028     SubsdelayEntryDestroy( p_entry );
1029 }
1030
1031 /*****************************************************************************
1032  * SubpicLocalUpdate: rewrite some of the subpicture parameters
1033  *****************************************************************************/
1034 static void SubpicLocalUpdate( subpicture_t* p_subpic, mtime_t i_ts )
1035 {
1036     subsdelay_heap_entry_t *p_entry;
1037     subsdelay_heap_t *p_heap;
1038     filter_t *p_filter;
1039
1040     int i_overlapping;
1041
1042     p_entry = p_subpic->updater.p_sys;
1043     if( !p_entry || !p_entry->p_filter )
1044     {
1045         return;
1046     }
1047
1048     p_filter = p_entry->p_filter;
1049     p_heap = &p_filter->p_sys->heap;
1050
1051     SubsdelayHeapLock( p_heap );
1052
1053     if( p_entry->b_check_empty && p_subpic->p_region )
1054     {
1055         if( SubsdelayIsTextEmpty( p_subpic->p_region->psz_html ) ||
1056             SubsdelayIsTextEmpty( p_subpic->p_region->psz_text ) )
1057         {
1058             /* remove empty subtitle */
1059
1060             p_subpic->b_ephemer = false;
1061             p_subpic->i_stop = p_subpic->i_start;
1062
1063             SubsdelayHeapRemove( p_heap, p_entry );
1064
1065             SubsdelayHeapUnlock( p_heap );
1066
1067             return;
1068         }
1069
1070         p_entry->b_check_empty = false;
1071     }
1072
1073     if( p_entry->b_update_stop && !p_entry->b_update_ephemer )
1074     {
1075         p_entry->i_new_stop = p_entry->p_source->i_start + SubsdelayEstimateDelay( p_filter, p_entry );
1076         p_entry->b_update_stop = false;
1077
1078         SubsdelayEnforceDelayRules( p_filter );
1079     }
1080
1081     i_overlapping = SubsdelayHeapCountOverlap( p_heap, p_entry, i_ts );
1082
1083     p_subpic->i_alpha = SubsdelayCalculateAlpha( p_filter, i_overlapping, p_entry->p_source->i_alpha );
1084
1085     if( p_entry->b_update_position )
1086     {
1087         p_subpic->b_absolute = false;
1088
1089         if( p_subpic->p_region )
1090         {
1091             p_subpic->p_region->i_x = 0;
1092             p_subpic->p_region->i_y = 10;
1093             p_subpic->p_region->i_align = ( p_subpic->p_region->i_align & ( ~SUBPICTURE_ALIGN_MASK ) )
1094                     | SUBPICTURE_ALIGN_BOTTOM;
1095         }
1096
1097         p_entry->b_update_position = false;
1098     }
1099     else if( p_entry->b_last_region_saved )
1100     {
1101         p_subpic->b_absolute = true;
1102
1103         if( p_subpic->p_region )
1104         {
1105             p_subpic->p_region->i_x = p_entry->i_last_region_x;
1106             p_subpic->p_region->i_y = p_entry->i_last_region_y;
1107             p_subpic->p_region->i_align = p_entry->i_last_region_align;
1108         }
1109     }
1110
1111     SubsdelayHeapUnlock( p_heap );
1112 }
1113
1114 /*****************************************************************************
1115  * SubpicIsEmpty: subpic region contains empty string
1116  *****************************************************************************/
1117 static bool SubpicIsEmpty( subpicture_t* p_subpic )
1118 {
1119     return ( p_subpic->p_region && ( SubsdelayIsTextEmpty( p_subpic->p_region->psz_html ) ||
1120                                      SubsdelayIsTextEmpty( p_subpic->p_region->psz_text ) ) );
1121 }
1122
1123 /*****************************************************************************
1124  * SubpicClone: Clone subpicture (shallow copy)
1125  *****************************************************************************/
1126 static subpicture_t *SubpicClone( subpicture_t *p_source, subpicture_updater_t *updater )
1127 {
1128     subpicture_t *p_subpic;
1129     subpicture_updater_t subpic_updater;
1130     subpicture_private_t *p_subpic_private;
1131
1132     p_subpic = subpicture_New( updater );
1133
1134     if( !p_subpic )
1135     {
1136         return NULL;
1137     }
1138
1139     /* save private members */
1140     subpic_updater = p_subpic->updater;
1141     p_subpic_private = p_subpic->p_private;
1142
1143     /* copy the entire struct */
1144     memcpy( p_subpic, p_source, sizeof( subpicture_t ) );
1145
1146     /* restore private members */
1147     p_subpic->updater = subpic_updater;
1148     p_subpic->p_private = p_subpic_private;
1149
1150     return p_subpic;
1151 }
1152
1153 /*****************************************************************************
1154  * SubpicDestroyClone: destroy cloned subpicture (shared references will not
1155  *     be destroyed)
1156  *****************************************************************************/
1157 static void SubpicDestroyClone( subpicture_t *p_subpic )
1158 {
1159     p_subpic->p_region = NULL; /* don't destroy region */
1160     subpicture_Delete( p_subpic );
1161 }
1162
1163 /*****************************************************************************
1164  * SubsdelayEstimateDelay: Calculate new subtitle delay according to its
1165  *     content and the calculation mode
1166  *****************************************************************************/
1167 static int64_t SubsdelayEstimateDelay( filter_t *p_filter, subsdelay_heap_entry_t *p_entry )
1168 {
1169     int i_mode;
1170     int i_factor;
1171     int i_rank;
1172
1173     i_mode = p_filter->p_sys->i_mode;
1174     i_factor = p_filter->p_sys->i_factor;
1175
1176     if( i_mode == SUBSDELAY_MODE_ABSOLUTE )
1177     {
1178         return ( p_entry->p_source->i_stop - p_entry->p_source->i_start + INT_FACTOR_TO_MICROSEC( i_factor ) );
1179     }
1180
1181     if( i_mode == SUBSDELAY_MODE_RELATIVE_SOURCE_CONTENT )
1182     {
1183         if( p_entry->p_subpic && p_entry->p_subpic->p_region && ( p_entry->p_subpic->p_region->psz_text
1184                 || p_entry->p_subpic->p_region->psz_html ) )
1185         {
1186             if( p_entry->p_subpic->p_region->psz_text )
1187             {
1188                 i_rank = SubsdelayGetTextRank( p_entry->p_subpic->p_region->psz_text );
1189             }
1190             else
1191             {
1192                 i_rank = SubsdelayGetTextRank( p_entry->p_subpic->p_region->psz_html );
1193             }
1194
1195             return ( i_rank * INT_FACTOR_TO_RANK_FACTOR( i_factor ) );
1196         }
1197
1198         /* content is unavailable, calculation mode should be based on source delay */
1199         i_mode = SUBSDELAY_MODE_RELATIVE_SOURCE_DELAY;
1200     }
1201
1202     if( i_mode == SUBSDELAY_MODE_RELATIVE_SOURCE_DELAY )
1203     {
1204         return ( ( i_factor * ( p_entry->p_source->i_stop - p_entry->p_source->i_start ) ) / INT_FACTOR_BASE );
1205     }
1206
1207     return 10000000; /* 10 sec */
1208 }
1209
1210 /*****************************************************************************
1211  * SubsdelayCalculateAlpha: Calculate subtitle alpha according to source alpha
1212  *     value and number of overlapping subtitles
1213  *****************************************************************************/
1214 static int SubsdelayCalculateAlpha( filter_t *p_filter, int i_overlapping, int i_source_alpha )
1215 {
1216     int i_new_alpha;
1217     int i_min_alpha;
1218
1219     i_min_alpha = p_filter->p_sys->i_min_alpha;
1220
1221     if( i_overlapping > p_filter->p_sys->i_overlap - 1)
1222     {
1223         i_overlapping = p_filter->p_sys->i_overlap - 1;
1224     }
1225
1226     switch ( p_filter->p_sys->i_overlap )
1227     {
1228     case 1:
1229         i_new_alpha = 255;
1230         break;
1231
1232     case 2:
1233         i_new_alpha = 255 - i_overlapping * ( 255 - i_min_alpha );
1234         break;
1235
1236     case 3:
1237         i_new_alpha = 255 - i_overlapping * ( 255 - i_min_alpha ) / 2;
1238         break;
1239
1240     default:
1241         i_new_alpha = 255 - i_overlapping * ( 255 - i_min_alpha ) / 3;
1242         break;
1243     }
1244
1245     return ( i_source_alpha * i_new_alpha ) / 255;
1246 }
1247
1248 /*****************************************************************************
1249  * SubsdelayGetWordRank: Calculate single word rank according to its length
1250  *****************************************************************************/
1251 static int SubsdelayGetWordRank( int i_length )
1252 {
1253     /* p_rank[0] = p_rank[1] = p_rank[2] = 300;
1254     for( i = 3; i < 20; i++ ) p_rank[i] = (int) ( 1.1 * p_rank[i - 1] ); */
1255
1256     static const int p_rank[20] = { 300, 300, 300, 330, 363, 399, 438, 481, 529, 581,
1257                                     639, 702, 772, 849, 933, 1026, 1128, 1240, 1364, 1500 };
1258
1259     if( i_length < 1 )
1260     {
1261         return 0;
1262     }
1263
1264     if( i_length > 20 )
1265     {
1266         i_length = 20;
1267     }
1268
1269     return p_rank[i_length - 1];
1270 }
1271
1272 /*****************************************************************************
1273  * SubsdelayGetTextRank: Calculate text rank
1274  *****************************************************************************/
1275 static int SubsdelayGetTextRank( char *psz_text )
1276 {
1277     bool b_skip_esc;
1278     bool b_skip_tag;
1279     char c;
1280
1281     int i, i_word_length, i_rank;
1282
1283     i = 0;
1284     i_word_length = 0;
1285     i_rank = 0;
1286
1287     b_skip_esc = false;
1288     b_skip_tag = false;
1289
1290     while ( psz_text[i] != '\0' )
1291     {
1292         c = psz_text[i];
1293         i++;
1294
1295         if( c == '\\' && !b_skip_esc )
1296         {
1297             b_skip_esc = true;
1298             continue;
1299         }
1300
1301         if( psz_text[i] == '<' )
1302         {
1303             b_skip_tag = true;
1304             continue;
1305         }
1306
1307         if( !b_skip_esc && !b_skip_tag )
1308         {
1309             if( c == ' ' || c == ',' || c == '.' || c == '-' || c == '?' || c == '!' ) /* common delimiters */
1310             {
1311                 if( i_word_length > 0 )
1312                 {
1313                     i_rank += SubsdelayGetWordRank( i_word_length );
1314                 }
1315
1316                 i_word_length = 0;
1317             }
1318             else
1319             {
1320                 i_word_length++;
1321             }
1322         }
1323
1324         b_skip_esc = false;
1325
1326         if( c == '>' )
1327         {
1328             b_skip_tag = false;
1329         }
1330
1331     }
1332
1333     if( i_word_length > 0 )
1334     {
1335         i_rank += SubsdelayGetWordRank( i_word_length );
1336     }
1337
1338     return i_rank;
1339 }
1340
1341 /*****************************************************************************
1342  * SubsdelayIsTextEmpty: Check if the text contains spaces only
1343  *****************************************************************************/
1344 static bool SubsdelayIsTextEmpty( char *psz_text )
1345 {
1346     if( !psz_text )
1347     {
1348         return false;
1349     }
1350
1351     psz_text += strspn( psz_text, " " );
1352     return !( *psz_text );
1353 }