modules/codec/libass.c

   1 /*****************************************************************************
   2  * SSA/ASS subtitle decoder using libass.
   3  *****************************************************************************
   4  * Copyright (C) 2008-2009 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, 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 <string.h>
  33 #include <limits.h>
  34 #include <assert.h>
  35 #include <math.h>
  36
  37 #include <vlc_common.h>
  38 #include <vlc_plugin.h>
  39 #include <vlc_codec.h>
  40 #include <vlc_input.h>
  41 #include <vlc_dialog.h>
  42
  43 #include <ass/ass.h>
  44
  45 #if defined(WIN32)
  46 #   include <vlc_charset.h>
  47 #endif
  48
  49 /* Compatibility with old libass */
  50 #if !defined(LIBASS_VERSION) || LIBASS_VERSION < 0x00907010
  51 #   define ASS_Renderer    ass_renderer_t
  52 #   define ASS_Library     ass_library_t
  53 #   define ASS_Track       ass_track_t
  54 #   define ASS_Image       ass_image_t
  55 #endif
  56
  57 /*****************************************************************************
  58  * Module descriptor
  59  *****************************************************************************/
  60 static int  Create ( vlc_object_t * );
  61 static void Destroy( vlc_object_t * );
  62
  63 vlc_module_begin ()
  64     set_shortname( N_("Subtitles (advanced)"))
  65     set_description( N_("Subtitle renderers using libass") )
  66     set_capability( "decoder", 100 )
  67     set_category( CAT_INPUT )
  68     set_subcategory( SUBCAT_INPUT_SCODEC )
  69     set_callbacks( Create, Destroy )
  70 vlc_module_end ()
  71
  72 /*****************************************************************************
  73  * Local prototypes
  74  *****************************************************************************/
  75 static subpicture_t *DecodeBlock( decoder_t *, block_t ** );
  76
  77 /* Yes libass sux with threads */
  78 typedef struct
  79 {
  80     vlc_object_t   *p_libvlc;
  81
  82     int             i_refcount;
  83     ASS_Library     *p_library;
  84     ASS_Renderer    *p_renderer;
  85     video_format_t  fmt;
  86 } ass_handle_t;
  87 static ass_handle_t *AssHandleHold( decoder_t *p_dec );
  88 static void AssHandleRelease( ass_handle_t * );
  89
  90 /* */
  91 struct decoder_sys_t
  92 {
  93     mtime_t      i_max_stop;
  94
  95     /* decoder_sys_t is shared between decoder and spu units */
  96     vlc_mutex_t  lock;
  97     int          i_refcount;
  98
  99     /* */
 100     ass_handle_t *p_ass;
 101
 102     /* */
 103     ASS_Track    *p_track;
 104 };
 105 static void DecSysRelease( decoder_sys_t *p_sys );
 106 static void DecSysHold( decoder_sys_t *p_sys );
 107
 108 /* */
 109 static int SubpictureValidate( subpicture_t *,
 110                                bool, const video_format_t *,
 111                                bool, const video_format_t *,
 112                                mtime_t );
 113 static void SubpictureUpdate( subpicture_t *,
 114                               const video_format_t *,
 115                               const video_format_t *,
 116                               mtime_t );
 117 static void SubpictureDestroy( subpicture_t * );
 118
 119 struct subpicture_updater_sys_t
 120 {
 121     decoder_sys_t *p_dec_sys;
 122     void          *p_subs_data;
 123     int           i_subs_len;
 124     mtime_t       i_pts;
 125
 126     ASS_Image     *p_img;
 127 };
 128
 129 typedef struct
 130 {
 131     int x0;
 132     int y0;
 133     int x1;
 134     int y1;
 135 } rectangle_t;
 136
 137 static int BuildRegions( rectangle_t *p_region, int i_max_region, ASS_Image *p_img_list, int i_width, int i_height );
 138 static void RegionDraw( subpicture_region_t *p_region, ASS_Image *p_img );
 139
 140 static vlc_mutex_t libass_lock = VLC_STATIC_MUTEX;
 141
 142 //#define DEBUG_REGION
 143
 144 /*****************************************************************************
 145  * Create: Open libass decoder.
 146  *****************************************************************************/
 147 static int Create( vlc_object_t *p_this )
 148 {
 149     decoder_t *p_dec = (decoder_t *)p_this;
 150     decoder_sys_t *p_sys;
 151     ASS_Track *p_track;
 152
 153     if( p_dec->fmt_in.i_codec != VLC_CODEC_SSA )
 154         return VLC_EGENERIC;
 155
 156     p_dec->pf_decode_sub = DecodeBlock;
 157
 158     p_dec->p_sys = p_sys = malloc( sizeof( decoder_sys_t ) );
 159     if( !p_sys )
 160         return VLC_ENOMEM;
 161
 162     /* */
 163     p_sys->i_max_stop = VLC_TS_INVALID;
 164     p_sys->p_ass = AssHandleHold( p_dec );
 165     if( !p_sys->p_ass )
 166     {
 167         free( p_sys );
 168         return VLC_EGENERIC;
 169     }
 170     vlc_mutex_init( &p_sys->lock );
 171     p_sys->i_refcount = 1;
 172
 173     /* Add a track */
 174     vlc_mutex_lock( &libass_lock );
 175     p_sys->p_track = p_track = ass_new_track( p_sys->p_ass->p_library );
 176     if( !p_track )
 177     {
 178         vlc_mutex_unlock( &libass_lock );
 179         DecSysRelease( p_sys );
 180         return VLC_EGENERIC;
 181     }
 182     ass_process_codec_private( p_track, p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra );
 183     vlc_mutex_unlock( &libass_lock );
 184
 185     p_dec->fmt_out.i_cat = SPU_ES;
 186     p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
 187
 188     return VLC_SUCCESS;
 189 }
 190
 191 /*****************************************************************************
 192  * Destroy: finish
 193  *****************************************************************************/
 194 static void Destroy( vlc_object_t *p_this )
 195 {
 196     decoder_t *p_dec = (decoder_t *)p_this;
 197
 198     DecSysRelease( p_dec->p_sys );
 199 }
 200
 201 static void DecSysHold( decoder_sys_t *p_sys )
 202 {
 203     vlc_mutex_lock( &p_sys->lock );
 204     p_sys->i_refcount++;
 205     vlc_mutex_unlock( &p_sys->lock );
 206 }
 207 static void DecSysRelease( decoder_sys_t *p_sys )
 208 {
 209     /* */
 210     vlc_mutex_lock( &p_sys->lock );
 211     p_sys->i_refcount--;
 212     if( p_sys->i_refcount > 0 )
 213     {
 214         vlc_mutex_unlock( &p_sys->lock );
 215         return;
 216     }
 217     vlc_mutex_unlock( &p_sys->lock );
 218     vlc_mutex_destroy( &p_sys->lock );
 219
 220     vlc_mutex_lock( &libass_lock );
 221     if( p_sys->p_track )
 222         ass_free_track( p_sys->p_track );
 223     vlc_mutex_unlock( &libass_lock );
 224
 225     AssHandleRelease( p_sys->p_ass );
 226     free( p_sys );
 227 }
 228
 229 /****************************************************************************
 230  * DecodeBlock:
 231  ****************************************************************************/
 232 static subpicture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 233 {
 234     decoder_sys_t *p_sys = p_dec->p_sys;
 235
 236     subpicture_t *p_spu = NULL;
 237     block_t *p_block;
 238
 239     if( !pp_block || *pp_block == NULL )
 240         return NULL;
 241
 242     p_block = *pp_block;
 243     if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 244     {
 245         p_sys->i_max_stop = VLC_TS_INVALID;
 246         block_Release( p_block );
 247         return NULL;
 248     }
 249     *pp_block = NULL;
 250
 251     if( p_block->i_buffer == 0 || p_block->p_buffer[0] == '\0' )
 252     {
 253         block_Release( p_block );
 254         return NULL;
 255     }
 256
 257     subpicture_updater_sys_t *p_spu_sys = malloc( sizeof(*p_spu_sys) );
 258     if( !p_spu_sys )
 259     {
 260         block_Release( p_block );
 261         return NULL;
 262     }
 263
 264     subpicture_updater_t updater = {
 265         .pf_validate = SubpictureValidate,
 266         .pf_update   = SubpictureUpdate,
 267         .pf_destroy  = SubpictureDestroy,
 268         .p_sys       = p_spu_sys,
 269     };
 270     p_spu = decoder_NewSubpicture( p_dec, &updater );
 271     if( !p_spu )
 272     {
 273         msg_Warn( p_dec, "can't get spu buffer" );
 274         free( p_spu_sys );
 275         block_Release( p_block );
 276         return NULL;
 277     }
 278
 279     p_spu_sys->p_img = NULL;
 280     p_spu_sys->p_dec_sys = p_sys;
 281     p_spu_sys->i_subs_len = p_block->i_buffer;
 282     p_spu_sys->p_subs_data = malloc( p_block->i_buffer );
 283     p_spu_sys->i_pts = p_block->i_pts;
 284     if( !p_spu_sys->p_subs_data )
 285     {
 286         decoder_DeleteSubpicture( p_dec, p_spu );
 287         block_Release( p_block );
 288         return NULL;
 289     }
 290     memcpy( p_spu_sys->p_subs_data, p_block->p_buffer,
 291             p_block->i_buffer );
 292
 293     p_spu->i_start = p_block->i_pts;
 294     p_spu->i_stop = __MAX( p_sys->i_max_stop, p_block->i_pts + p_block->i_length );
 295     p_spu->b_ephemer = true;
 296     p_spu->b_absolute = true;
 297
 298     p_sys->i_max_stop = p_spu->i_stop;
 299
 300     vlc_mutex_lock( &libass_lock );
 301     if( p_sys->p_track )
 302     {
 303         ass_process_chunk( p_sys->p_track, p_spu_sys->p_subs_data, p_spu_sys->i_subs_len,
 304                            p_block->i_pts / 1000, p_block->i_length / 1000 );
 305     }
 306     vlc_mutex_unlock( &libass_lock );
 307
 308     DecSysHold( p_sys ); /* Keep a reference for the returned subpicture */
 309
 310     block_Release( p_block );
 311
 312     return p_spu;
 313 }
 314
 315 /****************************************************************************
 316  *
 317  ****************************************************************************/
 318 static int SubpictureValidate( subpicture_t *p_subpic,
 319                                bool b_fmt_src, const video_format_t *p_fmt_src,
 320                                bool b_fmt_dst, const video_format_t *p_fmt_dst,
 321                                mtime_t i_ts )
 322 {
 323     decoder_sys_t *p_sys = p_subpic->updater.p_sys->p_dec_sys;
 324     ass_handle_t *p_ass = p_sys->p_ass;
 325
 326     vlc_mutex_lock( &libass_lock );
 327
 328     /* FIXME why this mix of src/dst */
 329     video_format_t fmt = *p_fmt_dst;
 330     fmt.i_chroma         = VLC_CODEC_RGBA;
 331     fmt.i_bits_per_pixel = 0;
 332     fmt.i_width          =
 333     fmt.i_visible_width  = p_fmt_src->i_width;
 334     fmt.i_height         =
 335     fmt.i_visible_height = p_fmt_src->i_height;
 336     fmt.i_x_offset       =
 337     fmt.i_y_offset       = 0;
 338
 339     if( b_fmt_src || b_fmt_dst )
 340     {
 341         ass_set_frame_size( p_ass->p_renderer, fmt.i_width, fmt.i_height );
 342 #if defined( LIBASS_VERSION ) && LIBASS_VERSION >= 0x00907000
 343         ass_set_aspect_ratio( p_ass->p_renderer, 1.0, 1.0 ); // TODO ?
 344 #else
 345         ass_set_aspect_ratio( p_ass->p_renderer, 1.0 ); // TODO ?
 346 #endif
 347         p_ass->fmt = fmt;
 348     }
 349
 350     /* */
 351     const mtime_t i_stream_date = p_subpic->updater.p_sys->i_pts + (i_ts - p_subpic->i_start);
 352     int i_changed;
 353     ASS_Image *p_img = ass_render_frame( p_ass->p_renderer, p_sys->p_track,
 354                                          i_stream_date/1000, &i_changed );
 355
 356     if( !i_changed && !b_fmt_src && !b_fmt_dst &&
 357         (p_img != NULL) == (p_subpic->p_region != NULL) )
 358     {
 359         vlc_mutex_unlock( &libass_lock );
 360         return VLC_SUCCESS;
 361     }
 362     p_subpic->updater.p_sys->p_img = p_img;
 363
 364     /* The lock is released by SubpictureUpdate */
 365     return VLC_EGENERIC;
 366 }
 367
 368 static void SubpictureUpdate( subpicture_t *p_subpic,
 369                               const video_format_t *p_fmt_src,
 370                               const video_format_t *p_fmt_dst,
 371                               mtime_t i_ts )
 372 {
 373     VLC_UNUSED( p_fmt_src ); VLC_UNUSED( p_fmt_dst ); VLC_UNUSED( i_ts );
 374
 375     decoder_sys_t *p_sys = p_subpic->updater.p_sys->p_dec_sys;
 376     ass_handle_t *p_ass = p_sys->p_ass;
 377
 378     video_format_t fmt = p_ass->fmt;
 379     ASS_Image *p_img = p_subpic->updater.p_sys->p_img;
 380     //vlc_assert_locked( &libass_lock );
 381
 382     /* */
 383     p_subpic->i_original_picture_height = fmt.i_height;
 384     p_subpic->i_original_picture_width = fmt.i_width;
 385
 386     /* XXX to improve efficiency we merge regions that are close minimizing
 387      * the lost surface.
 388      * libass tends to create a lot of small regions and thus spu engine
 389      * reinstanciate a lot the scaler, and as we do not support subpel blending
 390      * it looks ugly (text unaligned).
 391      */
 392     const int i_max_region = 4;
 393     rectangle_t region[i_max_region];
 394     const int i_region = BuildRegions( region, i_max_region, p_img, fmt.i_width, fmt.i_height );
 395
 396     if( i_region <= 0 )
 397     {
 398         vlc_mutex_unlock( &libass_lock );
 399         return;
 400     }
 401
 402     /* Allocate the regions and draw them */
 403     subpicture_region_t *pp_region[i_max_region];
 404     subpicture_region_t **pp_region_last = &p_subpic->p_region;
 405
 406     for( int i = 0; i < i_region; i++ )
 407     {
 408         subpicture_region_t *r;
 409         video_format_t fmt_region;
 410
 411         /* */
 412         fmt_region = fmt;
 413         fmt_region.i_width =
 414         fmt_region.i_visible_width  = region[i].x1 - region[i].x0;
 415         fmt_region.i_height =
 416         fmt_region.i_visible_height = region[i].y1 - region[i].y0;
 417
 418         pp_region[i] = r = subpicture_region_New( &fmt_region );
 419         if( !r )
 420             break;
 421         r->i_x = region[i].x0;
 422         r->i_y = region[i].y0;
 423         r->i_align = SUBPICTURE_ALIGN_TOP | SUBPICTURE_ALIGN_LEFT;
 424
 425         /* */
 426         RegionDraw( r, p_img );
 427
 428         /* */
 429         *pp_region_last = r;
 430         pp_region_last = &r->p_next;
 431     }
 432     vlc_mutex_unlock( &libass_lock );
 433
 434 }
 435 static void SubpictureDestroy( subpicture_t *p_subpic )
 436 {
 437     subpicture_updater_sys_t *p_sys = p_subpic->updater.p_sys;
 438
 439     DecSysRelease( p_sys->p_dec_sys );
 440     free( p_sys->p_subs_data );
 441     free( p_sys );
 442 }
 443
 444 static rectangle_t r_create( int x0, int y0, int x1, int y1 )
 445 {
 446     rectangle_t r = { x0, y0, x1, y1 };
 447     return r;
 448 }
 449 static rectangle_t r_img( const ASS_Image *p_img )
 450 {
 451     return r_create( p_img->dst_x, p_img->dst_y, p_img->dst_x+p_img->w, p_img->dst_y+p_img->h );
 452 }
 453 static void r_add( rectangle_t *r, const rectangle_t *n )
 454 {
 455     r->x0 = __MIN( r->x0, n->x0 );
 456     r->y0 = __MIN( r->y0, n->y0 );
 457     r->x1 = __MAX( r->x1, n->x1 );
 458     r->y1 = __MAX( r->y1, n->y1 );
 459 }
 460 static int r_surface( const rectangle_t *r )
 461 {
 462     return (r->x1-r->x0) * (r->y1-r->y0);
 463 }
 464 static bool r_overlap( const rectangle_t *a, const rectangle_t *b, int i_dx, int i_dy )
 465 {
 466     return  __MAX(a->x0-i_dx, b->x0) < __MIN( a->x1+i_dx, b->x1 ) &&
 467             __MAX(a->y0-i_dy, b->y0) < __MIN( a->y1+i_dy, b->y1 );
 468 }
 469
 470 static int BuildRegions( rectangle_t *p_region, int i_max_region, ASS_Image *p_img_list, int i_width, int i_height )
 471 {
 472     ASS_Image *p_tmp;
 473     int i_count;
 474
 475 #ifdef DEBUG_REGION
 476     int64_t i_ck_start = mdate();
 477 #endif
 478
 479     for( p_tmp = p_img_list, i_count = 0; p_tmp != NULL; p_tmp = p_tmp->next )
 480         if( p_tmp->w > 0 && p_tmp->h > 0 )
 481             i_count++;
 482     if( i_count <= 0 )
 483         return 0;
 484
 485     ASS_Image **pp_img = calloc( i_count, sizeof(*pp_img) );
 486     if( !pp_img )
 487         return 0;
 488
 489     for( p_tmp = p_img_list, i_count = 0; p_tmp != NULL; p_tmp = p_tmp->next )
 490         if( p_tmp->w > 0 && p_tmp->h > 0 )
 491             pp_img[i_count++] = p_tmp;
 492
 493     /* */
 494     const int i_w_inc = __MAX( ( i_width + 49 ) / 50, 32 );
 495     const int i_h_inc = __MAX( ( i_height + 99 ) / 100, 32 );
 496     int i_maxh = i_w_inc;
 497     int i_maxw = i_h_inc;
 498     int i_region;
 499     rectangle_t region[i_max_region+1];
 500
 501     i_region = 0;
 502     for( int i_used = 0; i_used < i_count; )
 503     {
 504         int n;
 505         for( n = 0; n < i_count; n++ )
 506         {
 507             if( pp_img[n] )
 508                 break;
 509         }
 510         assert( i_region < i_max_region + 1 );
 511         region[i_region++] = r_img( pp_img[n] );
 512         pp_img[n] = NULL; i_used++;
 513
 514         bool b_ok;
 515         do {
 516             b_ok = false;
 517             for( n = 0; n < i_count; n++ )
 518             {
 519                 ASS_Image *p_img = pp_img[n];
 520                 if( !p_img )
 521                     continue;
 522                 rectangle_t r = r_img( p_img );
 523
 524                 int k;
 525                 int i_best = -1;
 526                 int i_best_s = INT_MAX;
 527                 for( k = 0; k < i_region; k++ )
 528                 {
 529                     if( !r_overlap( &region[k], &r, i_maxw, i_maxh ) )
 530                         continue;
 531                     int s = r_surface( &r );
 532                     if( s < i_best_s )
 533                     {
 534                         i_best_s = s;
 535                         i_best = k;
 536                     }
 537                 }
 538                 if( i_best >= 0 )
 539                 {
 540                     r_add( &region[i_best], &r );
 541                     pp_img[n] = NULL; i_used++;
 542                     b_ok = true;
 543                 }
 544             }
 545         } while( b_ok );
 546
 547         if( i_region > i_max_region )
 548         {
 549             int i_best_i = -1;
 550             int i_best_j = -1;
 551             int i_best_ds = INT_MAX;
 552
 553             /* merge best */
 554             for( int i = 0; i < i_region; i++ )
 555             {
 556                 for( int j = i+1; j < i_region; j++ )
 557                 {
 558                     rectangle_t n = region[i];
 559                     r_add( &n, &region[j] );
 560                     int ds = r_surface( &n ) - r_surface( &region[i] ) - r_surface( &region[j] );
 561
 562                     if( ds < i_best_ds )
 563                     {
 564                         i_best_i = i;
 565                         i_best_j = j;
 566                         i_best_ds = ds;
 567                     }
 568                 }
 569             }
 570 #ifdef DEBUG_REGION
 571             msg_Err( p_spu, "Merging %d and %d", i_best_i, i_best_j );
 572 #endif
 573             r_add( &region[i_best_i], &region[i_best_j] );
 574
 575             if( i_best_j+1 < i_region )
 576                 memmove( &region[i_best_j], &region[i_best_j+1], sizeof(*region) * ( i_region - (i_best_j+1)  ) );
 577             i_region--;
 578         }
 579     }
 580
 581     /* */
 582     for( int n = 0; n < i_region; n++ )
 583         p_region[n] = region[n];
 584
 585 #ifdef DEBUG_REGION
 586     int64_t i_ck_time = mdate() - i_ck_start;
 587     msg_Err( p_spu, "ASS: %d objects merged into %d region in %d micros", i_count, i_region, (int)(i_ck_time) );
 588 #endif
 589
 590     free( pp_img );
 591
 592     return i_region;
 593 }
 594
 595 static void RegionDraw( subpicture_region_t *p_region, ASS_Image *p_img )
 596 {
 597     const plane_t *p = &p_region->p_picture->p[0];
 598     const int i_x = p_region->i_x;
 599     const int i_y = p_region->i_y;
 600     const int i_width  = p_region->fmt.i_width;
 601     const int i_height = p_region->fmt.i_height;
 602
 603     memset( p->p_pixels, 0x00, p->i_pitch * p->i_lines );
 604     for( ; p_img != NULL; p_img = p_img->next )
 605     {
 606         if( p_img->dst_x < i_x || p_img->dst_x + p_img->w > i_x + i_width ||
 607             p_img->dst_y < i_y || p_img->dst_y + p_img->h > i_y + i_height )
 608             continue;
 609
 610         const unsigned r = (p_img->color >> 24)&0xff;
 611         const unsigned g = (p_img->color >> 16)&0xff;
 612         const unsigned b = (p_img->color >>  8)&0xff;
 613         const unsigned a = (p_img->color      )&0xff;
 614         int x, y;
 615
 616         for( y = 0; y < p_img->h; y++ )
 617         {
 618             for( x = 0; x < p_img->w; x++ )
 619             {
 620                 const unsigned alpha = p_img->bitmap[y*p_img->stride+x];
 621                 const unsigned an = (255 - a) * alpha / 255;
 622
 623                 uint8_t *p_rgba = &p->p_pixels[(y+p_img->dst_y-i_y) * p->i_pitch + 4 * (x+p_img->dst_x-i_x)];
 624                 const unsigned ao = p_rgba[3];
 625
 626                 /* Native endianness, but RGBA ordering */
 627                 if( ao == 0 )
 628                 {
 629                     /* Optimized but the else{} will produce the same result */
 630                     p_rgba[0] = r;
 631                     p_rgba[1] = g;
 632                     p_rgba[2] = b;
 633                     p_rgba[3] = an;
 634                 }
 635                 else
 636                 {
 637                     p_rgba[3] = 255 - ( 255 - p_rgba[3] ) * ( 255 - an ) / 255;
 638                     if( p_rgba[3] != 0 )
 639                     {
 640                         p_rgba[0] = ( p_rgba[0] * ao * (255-an) / 255 + r * an ) / p_rgba[3];
 641                         p_rgba[1] = ( p_rgba[1] * ao * (255-an) / 255 + g * an ) / p_rgba[3];
 642                         p_rgba[2] = ( p_rgba[2] * ao * (255-an) / 255 + b * an ) / p_rgba[3];
 643                     }
 644                 }
 645             }
 646         }
 647     }
 648
 649 #ifdef DEBUG_REGION
 650     /* XXX Draw a box for debug */
 651 #define P(x,y) ((uint32_t*)&p->p_pixels[(y)*p->i_pitch + 4*(x)])
 652     for( int y = 0; y < p->i_lines; y++ )
 653         *P(0,y) = *P(p->i_visible_pitch/4-1,y) = 0xff000000;
 654     for( int x = 0; x < p->i_visible_pitch; x++ )
 655         *P(x/4,0) = *P(x/4,p->i_visible_lines-1) = 0xff000000;
 656 #undef P
 657 #endif
 658 }
 659
 660 /* */
 661 static ass_handle_t *AssHandleHold( decoder_t *p_dec )
 662 {
 663     vlc_mutex_lock( &libass_lock );
 664
 665     ass_handle_t *p_ass = NULL;
 666     ASS_Library *p_library = NULL;
 667     ASS_Renderer *p_renderer = NULL;
 668     vlc_value_t val;
 669
 670     var_Create( p_dec->p_libvlc, "libass-handle", VLC_VAR_ADDRESS );
 671     if( var_Get( p_dec->p_libvlc, "libass-handle", &val ) )
 672         val.p_address = NULL;
 673
 674     if( val.p_address )
 675     {
 676         p_ass = val.p_address;
 677
 678         p_ass->i_refcount++;
 679
 680         vlc_mutex_unlock( &libass_lock );
 681         return p_ass;
 682     }
 683
 684     /* */
 685     p_ass = malloc( sizeof(*p_ass) );
 686     if( !p_ass )
 687         goto error;
 688
 689     /* */
 690     p_ass->p_libvlc = VLC_OBJECT(p_dec->p_libvlc);
 691     p_ass->i_refcount = 1;
 692
 693     /* Create libass library */
 694     p_ass->p_library = p_library = ass_library_init();
 695     if( !p_library )
 696         goto error;
 697
 698     /* load attachments */
 699     input_attachment_t  **pp_attachments;
 700     int                   i_attachments;
 701
 702     if( decoder_GetInputAttachments( p_dec, &pp_attachments, &i_attachments ))
 703     {
 704         i_attachments = 0;
 705         pp_attachments = NULL;
 706     }
 707     for( int k = 0; k < i_attachments; k++ )
 708     {
 709         input_attachment_t *p_attach = pp_attachments[k];
 710
 711         if( !strcasecmp( p_attach->psz_mime, "application/x-truetype-font" ) )
 712         {
 713             msg_Dbg( p_dec, "adding embedded font %s", p_attach->psz_name );
 714
 715             ass_add_font( p_ass->p_library, p_attach->psz_name, p_attach->p_data, p_attach->i_data );
 716         }
 717         vlc_input_attachment_Delete( p_attach );
 718     }
 719     free( pp_attachments );
 720
 721     ass_set_extract_fonts( p_library, true );
 722     ass_set_style_overrides( p_library, NULL );
 723
 724     /* Create the renderer */
 725     p_ass->p_renderer = p_renderer = ass_renderer_init( p_library );
 726     if( !p_renderer )
 727         goto error;
 728
 729     ass_set_use_margins( p_renderer, false);
 730     //if( false )
 731     //    ass_set_margins( p_renderer, int t, int b, int l, int r);
 732     ass_set_hinting( p_renderer, ASS_HINTING_LIGHT );
 733     ass_set_font_scale( p_renderer, 1.0 );
 734     ass_set_line_spacing( p_renderer, 0.0 );
 735
 736     const char *psz_font = NULL; /* We don't ship a default font with VLC */
 737     const char *psz_family = "Arial"; /* Use Arial if we can't find anything more suitable */
 738
 739 #ifdef HAVE_FONTCONFIG
 740 #if defined(WIN32)
 741     dialog_progress_bar_t *p_dialog = dialog_ProgressCreate( p_dec,
 742         _("Building font cache"),
 743         _( "Please wait while your font cache is rebuilt.\n"
 744         "This should take less than a minute." ), NULL );
 745     if( p_dialog )
 746         dialog_ProgressSet( p_dialog, NULL, 0.2 );
 747 #endif
 748 #if defined( LIBASS_VERSION ) && LIBASS_VERSION >= 0x00907000
 749     ass_set_fonts( p_renderer, psz_font, psz_family, true, NULL, 1 );  // setup default font/family
 750 #else
 751     ass_set_fonts( p_renderer, psz_font, psz_family );  // setup default font/family
 752 #endif
 753 #ifdef WIN32
 754     if( p_dialog )
 755     {
 756         dialog_ProgressSet( p_dialog, NULL, 1.0 );
 757         dialog_ProgressDestroy( p_dialog );
 758         p_dialog = NULL;
 759     }
 760 #endif
 761 #else
 762     /* FIXME you HAVE to give him a font if no fontconfig */
 763 #if defined( LIBASS_VERSION ) && LIBASS_VERSION >= 0x00907000
 764     ass_set_fonts( p_renderer, psz_font, psz_family, false, NULL, 1 );
 765 #else
 766     ass_set_fonts_nofc( p_renderer, psz_font, psz_family );
 767 #endif
 768 #endif
 769     memset( &p_ass->fmt, 0, sizeof(p_ass->fmt) );
 770
 771     /* */
 772     val.p_address = p_ass;
 773     var_Set( p_dec->p_libvlc, "libass-handle", val );
 774
 775     /* */
 776     vlc_mutex_unlock( &libass_lock );
 777     return p_ass;
 778
 779 error:
 780     if( p_renderer )
 781         ass_renderer_done( p_renderer );
 782     if( p_library )
 783         ass_library_done( p_library );
 784
 785     msg_Warn( p_dec, "Libass creation failed" );
 786
 787     free( p_ass );
 788     vlc_mutex_unlock( &libass_lock );
 789     return NULL;
 790 }
 791 static void AssHandleRelease( ass_handle_t *p_ass )
 792 {
 793     vlc_mutex_lock( &libass_lock );
 794     p_ass->i_refcount--;
 795     if( p_ass->i_refcount > 0 )
 796     {
 797         vlc_mutex_unlock( &libass_lock );
 798         return;
 799     }
 800
 801     ass_renderer_done( p_ass->p_renderer );
 802     ass_library_done( p_ass->p_library );
 803
 804     vlc_value_t val;
 805     val.p_address = NULL;
 806     var_Set( p_ass->p_libvlc, "libass-handle", val );
 807
 808     vlc_mutex_unlock( &libass_lock );
 809     free( p_ass );
 810 }