modules/codec/libass.c

   1 /*****************************************************************************
   2  * SSA/ASS subtitle decoder using libass.
   3  *****************************************************************************
   4  * Copyright (C) 2008-2009 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir@videolan.org>
   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 <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 /*****************************************************************************
  50  * Module descriptor
  51  *****************************************************************************/
  52 static int  Create ( vlc_object_t * );
  53 static void Destroy( vlc_object_t * );
  54
  55 vlc_module_begin ()
  56     set_shortname( N_("Subtitles (advanced)"))
  57     set_description( N_("Subtitle renderers using libass") )
  58     set_capability( "decoder", 100 )
  59     set_category( CAT_INPUT )
  60     set_subcategory( SUBCAT_INPUT_SCODEC )
  61     set_callbacks( Create, Destroy )
  62 vlc_module_end ()
  63
  64 /*****************************************************************************
  65  * Local prototypes
  66  *****************************************************************************/
  67 static subpicture_t *DecodeBlock( decoder_t *, block_t ** );
  68
  69 /* */
  70 struct decoder_sys_t
  71 {
  72     mtime_t        i_max_stop;
  73
  74     /* The following fields of decoder_sys_t are shared between decoder and spu units */
  75     vlc_mutex_t    lock;
  76     int            i_refcount;
  77
  78     /* */
  79     ASS_Library    *p_library;
  80     ASS_Renderer   *p_renderer;
  81     video_format_t fmt;
  82
  83     /* */
  84     ASS_Track      *p_track;
  85 };
  86 static void DecSysRelease( decoder_sys_t *p_sys );
  87 static void DecSysHold( decoder_sys_t *p_sys );
  88
  89 /* */
  90 static int SubpictureValidate( subpicture_t *,
  91                                bool, const video_format_t *,
  92                                bool, const video_format_t *,
  93                                mtime_t );
  94 static void SubpictureUpdate( subpicture_t *,
  95                               const video_format_t *,
  96                               const video_format_t *,
  97                               mtime_t );
  98 static void SubpictureDestroy( subpicture_t * );
  99
 100 struct subpicture_updater_sys_t
 101 {
 102     decoder_sys_t *p_dec_sys;
 103     void          *p_subs_data;
 104     int           i_subs_len;
 105     mtime_t       i_pts;
 106
 107     ASS_Image     *p_img;
 108 };
 109
 110 typedef struct
 111 {
 112     int x0;
 113     int y0;
 114     int x1;
 115     int y1;
 116 } rectangle_t;
 117
 118 static int BuildRegions( rectangle_t *p_region, int i_max_region, ASS_Image *p_img_list, int i_width, int i_height );
 119 static void RegionDraw( subpicture_region_t *p_region, ASS_Image *p_img );
 120
 121 //#define DEBUG_REGION
 122
 123 /*****************************************************************************
 124  * Create: Open libass decoder.
 125  *****************************************************************************/
 126 static int Create( vlc_object_t *p_this )
 127 {
 128     decoder_t *p_dec = (decoder_t *)p_this;
 129     decoder_sys_t *p_sys;
 130
 131     if( p_dec->fmt_in.i_codec != VLC_CODEC_SSA )
 132         return VLC_EGENERIC;
 133
 134     p_dec->pf_decode_sub = DecodeBlock;
 135
 136     p_dec->p_sys = p_sys = malloc( sizeof( decoder_sys_t ) );
 137     if( !p_sys )
 138         return VLC_ENOMEM;
 139
 140     /* */
 141     vlc_mutex_init( &p_sys->lock );
 142     p_sys->i_refcount = 1;
 143     memset( &p_sys->fmt, 0, sizeof(p_sys->fmt) );
 144     p_sys->i_max_stop = VLC_TS_INVALID;
 145     p_sys->p_library  = NULL;
 146     p_sys->p_renderer = NULL;
 147     p_sys->p_track    = NULL;
 148
 149     /* Create libass library */
 150     ASS_Library *p_library = p_sys->p_library = ass_library_init();
 151     if( !p_library )
 152     {
 153         msg_Warn( p_dec, "Libass library creation failed" );
 154         DecSysRelease( p_sys );
 155         return VLC_EGENERIC;
 156     }
 157
 158     /* load attachments */
 159     input_attachment_t  **pp_attachments;
 160     int                   i_attachments;
 161     if( decoder_GetInputAttachments( p_dec, &pp_attachments, &i_attachments ))
 162     {
 163         i_attachments = 0;
 164         pp_attachments = NULL;
 165     }
 166     for( int k = 0; k < i_attachments; k++ )
 167     {
 168         input_attachment_t *p_attach = pp_attachments[k];
 169
 170         bool found = false;
 171
 172         /* Check mimetype*/
 173         if( !strcasecmp( p_attach->psz_mime, "application/x-truetype-font" ) )
 174             found = true;
 175         /* Then extension */
 176         else if( !found && strlen( p_attach->psz_name ) > 4 )
 177         {
 178             char *ext = p_attach->psz_name + strlen( p_attach->psz_name ) - 4;
 179
 180             if( !strcasecmp( ext, ".ttf" ) || !strcasecmp( ext, ".otf" ) || !strcasecmp( ext, ".ttc" ) )
 181                 found = true;
 182         }
 183
 184         if( found )
 185         {
 186             msg_Dbg( p_dec, "adding embedded font %s", p_attach->psz_name );
 187
 188             ass_add_font( p_sys->p_library, p_attach->psz_name, p_attach->p_data, p_attach->i_data );
 189         }
 190         vlc_input_attachment_Delete( p_attach );
 191     }
 192     free( pp_attachments );
 193
 194     ass_set_extract_fonts( p_library, true );
 195     ass_set_style_overrides( p_library, NULL );
 196
 197     /* Create the renderer */
 198     ASS_Renderer *p_renderer = p_sys->p_renderer = ass_renderer_init( p_library );
 199     if( !p_renderer )
 200     {
 201         msg_Warn( p_dec, "Libass renderer creation failed" );
 202         DecSysRelease( p_sys );
 203         return VLC_EGENERIC;
 204     }
 205
 206     ass_set_use_margins( p_renderer, false);
 207     //if( false )
 208     //    ass_set_margins( p_renderer, int t, int b, int l, int r);
 209     ass_set_hinting( p_renderer, ASS_HINTING_LIGHT );
 210     ass_set_font_scale( p_renderer, 1.0 );
 211     ass_set_line_spacing( p_renderer, 0.0 );
 212
 213 #if defined( __ANDROID__ )
 214     const char *psz_font = "/system/fonts/DroidSans-Bold.ttf";
 215     const char *psz_family = "Droid Sans Bold";
 216 #else
 217     const char *psz_font = NULL; /* We don't ship a default font with VLC */
 218     const char *psz_family = "Arial"; /* Use Arial if we can't find anything more suitable */
 219 #endif
 220
 221 #ifdef HAVE_FONTCONFIG
 222 #if defined(_WIN32)
 223     dialog_progress_bar_t *p_dialog =
 224         dialog_ProgressCreate( p_dec,
 225                                _("Building font cache"),
 226                                _( "Please wait while your font cache is rebuilt.\n"
 227                                   "This should take less than a minute." ), NULL );
 228 #endif
 229     ass_set_fonts( p_renderer, psz_font, psz_family, true, NULL, 1 );  // setup default font/family
 230 #ifdef _WIN32
 231     if( p_dialog )
 232     {
 233         dialog_ProgressSet( p_dialog, NULL, 1.0 );
 234         dialog_ProgressDestroy( p_dialog );
 235     }
 236 #endif
 237 #else
 238     /* FIXME you HAVE to give him a font if no fontconfig */
 239     ass_set_fonts( p_renderer, psz_font, psz_family, false, NULL, 1 );
 240 #endif
 241
 242     /* Add a track */
 243     ASS_Track *p_track = p_sys->p_track = ass_new_track( p_sys->p_library );
 244     if( !p_track )
 245     {
 246         DecSysRelease( p_sys );
 247         return VLC_EGENERIC;
 248     }
 249     ass_process_codec_private( p_track, p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra );
 250
 251     p_dec->fmt_out.i_cat = SPU_ES;
 252     p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
 253
 254     return VLC_SUCCESS;
 255 }
 256
 257 /*****************************************************************************
 258  * Destroy: finish
 259  *****************************************************************************/
 260 static void Destroy( vlc_object_t *p_this )
 261 {
 262     decoder_t *p_dec = (decoder_t *)p_this;
 263
 264     DecSysRelease( p_dec->p_sys );
 265 }
 266
 267 static void DecSysHold( decoder_sys_t *p_sys )
 268 {
 269     vlc_mutex_lock( &p_sys->lock );
 270     p_sys->i_refcount++;
 271     vlc_mutex_unlock( &p_sys->lock );
 272 }
 273 static void DecSysRelease( decoder_sys_t *p_sys )
 274 {
 275     /* */
 276     vlc_mutex_lock( &p_sys->lock );
 277     p_sys->i_refcount--;
 278     if( p_sys->i_refcount > 0 )
 279     {
 280         vlc_mutex_unlock( &p_sys->lock );
 281         return;
 282     }
 283     vlc_mutex_unlock( &p_sys->lock );
 284     vlc_mutex_destroy( &p_sys->lock );
 285
 286     if( p_sys->p_track )
 287         ass_free_track( p_sys->p_track );
 288     if( p_sys->p_renderer )
 289         ass_renderer_done( p_sys->p_renderer );
 290     if( p_sys->p_library )
 291         ass_library_done( p_sys->p_library );
 292
 293     free( p_sys );
 294 }
 295
 296 /****************************************************************************
 297  * DecodeBlock:
 298  ****************************************************************************/
 299 static subpicture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 300 {
 301     decoder_sys_t *p_sys = p_dec->p_sys;
 302
 303     subpicture_t *p_spu = NULL;
 304     block_t *p_block;
 305
 306     if( !pp_block || *pp_block == NULL )
 307         return NULL;
 308
 309     p_block = *pp_block;
 310     if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY|BLOCK_FLAG_CORRUPTED) )
 311     {
 312         p_sys->i_max_stop = VLC_TS_INVALID;
 313         block_Release( p_block );
 314         return NULL;
 315     }
 316     *pp_block = NULL;
 317
 318     if( p_block->i_buffer == 0 || p_block->p_buffer[0] == '\0' )
 319     {
 320         block_Release( p_block );
 321         return NULL;
 322     }
 323
 324     subpicture_updater_sys_t *p_spu_sys = malloc( sizeof(*p_spu_sys) );
 325     if( !p_spu_sys )
 326     {
 327         block_Release( p_block );
 328         return NULL;
 329     }
 330
 331     subpicture_updater_t updater = {
 332         .pf_validate = SubpictureValidate,
 333         .pf_update   = SubpictureUpdate,
 334         .pf_destroy  = SubpictureDestroy,
 335         .p_sys       = p_spu_sys,
 336     };
 337     p_spu = decoder_NewSubpicture( p_dec, &updater );
 338     if( !p_spu )
 339     {
 340         msg_Warn( p_dec, "can't get spu buffer" );
 341         free( p_spu_sys );
 342         block_Release( p_block );
 343         return NULL;
 344     }
 345
 346     p_spu_sys->p_img = NULL;
 347     p_spu_sys->p_dec_sys = p_sys;
 348     p_spu_sys->i_subs_len = p_block->i_buffer;
 349     p_spu_sys->p_subs_data = malloc( p_block->i_buffer );
 350     p_spu_sys->i_pts = p_block->i_pts;
 351     if( !p_spu_sys->p_subs_data )
 352     {
 353         decoder_DeleteSubpicture( p_dec, p_spu );
 354         block_Release( p_block );
 355         return NULL;
 356     }
 357     memcpy( p_spu_sys->p_subs_data, p_block->p_buffer,
 358             p_block->i_buffer );
 359
 360     p_spu->i_start = p_block->i_pts;
 361     p_spu->i_stop = __MAX( p_sys->i_max_stop, p_block->i_pts + p_block->i_length );
 362     p_spu->b_ephemer = true;
 363     p_spu->b_absolute = true;
 364
 365     p_sys->i_max_stop = p_spu->i_stop;
 366
 367     vlc_mutex_lock( &p_sys->lock );
 368     if( p_sys->p_track )
 369     {
 370         ass_process_chunk( p_sys->p_track, p_spu_sys->p_subs_data, p_spu_sys->i_subs_len,
 371                            p_block->i_pts / 1000, p_block->i_length / 1000 );
 372     }
 373     vlc_mutex_unlock( &p_sys->lock );
 374
 375     DecSysHold( p_sys ); /* Keep a reference for the returned subpicture */
 376
 377     block_Release( p_block );
 378
 379     return p_spu;
 380 }
 381
 382 /****************************************************************************
 383  *
 384  ****************************************************************************/
 385 static int SubpictureValidate( subpicture_t *p_subpic,
 386                                bool b_fmt_src, const video_format_t *p_fmt_src,
 387                                bool b_fmt_dst, const video_format_t *p_fmt_dst,
 388                                mtime_t i_ts )
 389 {
 390     decoder_sys_t *p_sys = p_subpic->updater.p_sys->p_dec_sys;
 391
 392     vlc_mutex_lock( &p_sys->lock );
 393
 394     video_format_t fmt = *p_fmt_dst;
 395     fmt.i_chroma         = VLC_CODEC_RGBA;
 396     fmt.i_bits_per_pixel = 0;
 397     fmt.i_visible_width  = fmt.i_width;
 398     fmt.i_visible_height = fmt.i_height;
 399     fmt.i_x_offset       = 0;
 400     fmt.i_y_offset       = 0;
 401     if( b_fmt_src || b_fmt_dst )
 402     {
 403         ass_set_frame_size( p_sys->p_renderer, fmt.i_width, fmt.i_height );
 404         const double src_ratio = (double)p_fmt_src->i_width / p_fmt_src->i_height;
 405         const double dst_ratio = (double)p_fmt_dst->i_width / p_fmt_dst->i_height;
 406         ass_set_aspect_ratio( p_sys->p_renderer, dst_ratio / src_ratio, 1 );
 407         p_sys->fmt = fmt;
 408     }
 409
 410     /* */
 411     const mtime_t i_stream_date = p_subpic->updater.p_sys->i_pts + (i_ts - p_subpic->i_start);
 412     int i_changed;
 413     ASS_Image *p_img = ass_render_frame( p_sys->p_renderer, p_sys->p_track,
 414                                          i_stream_date/1000, &i_changed );
 415
 416     if( !i_changed && !b_fmt_src && !b_fmt_dst &&
 417         (p_img != NULL) == (p_subpic->p_region != NULL) )
 418     {
 419         vlc_mutex_unlock( &p_sys->lock );
 420         return VLC_SUCCESS;
 421     }
 422     p_subpic->updater.p_sys->p_img = p_img;
 423
 424     /* The lock is released by SubpictureUpdate */
 425     return VLC_EGENERIC;
 426 }
 427
 428 static void SubpictureUpdate( subpicture_t *p_subpic,
 429                               const video_format_t *p_fmt_src,
 430                               const video_format_t *p_fmt_dst,
 431                               mtime_t i_ts )
 432 {
 433     VLC_UNUSED( p_fmt_src ); VLC_UNUSED( p_fmt_dst ); VLC_UNUSED( i_ts );
 434
 435     decoder_sys_t *p_sys = p_subpic->updater.p_sys->p_dec_sys;
 436
 437     video_format_t fmt = p_sys->fmt;
 438     ASS_Image *p_img = p_subpic->updater.p_sys->p_img;
 439
 440     /* */
 441     p_subpic->i_original_picture_height = fmt.i_height;
 442     p_subpic->i_original_picture_width = fmt.i_width;
 443
 444     /* XXX to improve efficiency we merge regions that are close minimizing
 445      * the lost surface.
 446      * libass tends to create a lot of small regions and thus spu engine
 447      * reinstanciate a lot the scaler, and as we do not support subpel blending
 448      * it looks ugly (text unaligned).
 449      */
 450     const int i_max_region = 4;
 451     rectangle_t region[i_max_region];
 452     const int i_region = BuildRegions( region, i_max_region, p_img, fmt.i_width, fmt.i_height );
 453
 454     if( i_region <= 0 )
 455     {
 456         vlc_mutex_unlock( &p_sys->lock );
 457         return;
 458     }
 459
 460     /* Allocate the regions and draw them */
 461     subpicture_region_t **pp_region_last = &p_subpic->p_region;
 462
 463     for( int i = 0; i < i_region; i++ )
 464     {
 465         subpicture_region_t *r;
 466         video_format_t fmt_region;
 467
 468         /* */
 469         fmt_region = fmt;
 470         fmt_region.i_width =
 471         fmt_region.i_visible_width  = region[i].x1 - region[i].x0;
 472         fmt_region.i_height =
 473         fmt_region.i_visible_height = region[i].y1 - region[i].y0;
 474
 475         r = subpicture_region_New( &fmt_region );
 476         if( !r )
 477             break;
 478         r->i_x = region[i].x0;
 479         r->i_y = region[i].y0;
 480         r->i_align = SUBPICTURE_ALIGN_TOP | SUBPICTURE_ALIGN_LEFT;
 481
 482         /* */
 483         RegionDraw( r, p_img );
 484
 485         /* */
 486         *pp_region_last = r;
 487         pp_region_last = &r->p_next;
 488     }
 489     vlc_mutex_unlock( &p_sys->lock );
 490
 491 }
 492 static void SubpictureDestroy( subpicture_t *p_subpic )
 493 {
 494     subpicture_updater_sys_t *p_sys = p_subpic->updater.p_sys;
 495
 496     DecSysRelease( p_sys->p_dec_sys );
 497     free( p_sys->p_subs_data );
 498     free( p_sys );
 499 }
 500
 501 static rectangle_t r_create( int x0, int y0, int x1, int y1 )
 502 {
 503     rectangle_t r = { x0, y0, x1, y1 };
 504     return r;
 505 }
 506 static rectangle_t r_img( const ASS_Image *p_img )
 507 {
 508     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 );
 509 }
 510 static void r_add( rectangle_t *r, const rectangle_t *n )
 511 {
 512     r->x0 = __MIN( r->x0, n->x0 );
 513     r->y0 = __MIN( r->y0, n->y0 );
 514     r->x1 = __MAX( r->x1, n->x1 );
 515     r->y1 = __MAX( r->y1, n->y1 );
 516 }
 517 static int r_surface( const rectangle_t *r )
 518 {
 519     return (r->x1-r->x0) * (r->y1-r->y0);
 520 }
 521 static bool r_overlap( const rectangle_t *a, const rectangle_t *b, int i_dx, int i_dy )
 522 {
 523     return  __MAX(a->x0-i_dx, b->x0) < __MIN( a->x1+i_dx, b->x1 ) &&
 524             __MAX(a->y0-i_dy, b->y0) < __MIN( a->y1+i_dy, b->y1 );
 525 }
 526
 527 static int BuildRegions( rectangle_t *p_region, int i_max_region, ASS_Image *p_img_list, int i_width, int i_height )
 528 {
 529     ASS_Image *p_tmp;
 530     int i_count;
 531
 532 #ifdef DEBUG_REGION
 533     int64_t i_ck_start = mdate();
 534 #endif
 535
 536     for( p_tmp = p_img_list, i_count = 0; p_tmp != NULL; p_tmp = p_tmp->next )
 537         if( p_tmp->w > 0 && p_tmp->h > 0 )
 538             i_count++;
 539     if( i_count <= 0 )
 540         return 0;
 541
 542     ASS_Image **pp_img = calloc( i_count, sizeof(*pp_img) );
 543     if( !pp_img )
 544         return 0;
 545
 546     for( p_tmp = p_img_list, i_count = 0; p_tmp != NULL; p_tmp = p_tmp->next )
 547         if( p_tmp->w > 0 && p_tmp->h > 0 )
 548             pp_img[i_count++] = p_tmp;
 549
 550     /* */
 551     const int i_w_inc = __MAX( ( i_width + 49 ) / 50, 32 );
 552     const int i_h_inc = __MAX( ( i_height + 99 ) / 100, 32 );
 553     int i_maxh = i_w_inc;
 554     int i_maxw = i_h_inc;
 555     int i_region;
 556     rectangle_t region[i_max_region+1];
 557
 558     i_region = 0;
 559     for( int i_used = 0; i_used < i_count; )
 560     {
 561         int n;
 562         for( n = 0; n < i_count; n++ )
 563         {
 564             if( pp_img[n] )
 565                 break;
 566         }
 567         assert( i_region < i_max_region + 1 );
 568         region[i_region++] = r_img( pp_img[n] );
 569         pp_img[n] = NULL; i_used++;
 570
 571         bool b_ok;
 572         do {
 573             b_ok = false;
 574             for( n = 0; n < i_count; n++ )
 575             {
 576                 ASS_Image *p_img = pp_img[n];
 577                 if( !p_img )
 578                     continue;
 579                 rectangle_t r = r_img( p_img );
 580
 581                 int k;
 582                 int i_best = -1;
 583                 int i_best_s = INT_MAX;
 584                 for( k = 0; k < i_region; k++ )
 585                 {
 586                     if( !r_overlap( &region[k], &r, i_maxw, i_maxh ) )
 587                         continue;
 588                     int s = r_surface( &r );
 589                     if( s < i_best_s )
 590                     {
 591                         i_best_s = s;
 592                         i_best = k;
 593                     }
 594                 }
 595                 if( i_best >= 0 )
 596                 {
 597                     r_add( &region[i_best], &r );
 598                     pp_img[n] = NULL; i_used++;
 599                     b_ok = true;
 600                 }
 601             }
 602         } while( b_ok );
 603
 604         if( i_region > i_max_region )
 605         {
 606             int i_best_i = -1;
 607             int i_best_j = -1;
 608             int i_best_ds = INT_MAX;
 609
 610             /* merge best */
 611             for( int i = 0; i < i_region; i++ )
 612             {
 613                 for( int j = i+1; j < i_region; j++ )
 614                 {
 615                     rectangle_t n = region[i];
 616                     r_add( &n, &region[j] );
 617                     int ds = r_surface( &n ) - r_surface( &region[i] ) - r_surface( &region[j] );
 618
 619                     if( ds < i_best_ds )
 620                     {
 621                         i_best_i = i;
 622                         i_best_j = j;
 623                         i_best_ds = ds;
 624                     }
 625                 }
 626             }
 627 #ifdef DEBUG_REGION
 628             msg_Err( p_spu, "Merging %d and %d", i_best_i, i_best_j );
 629 #endif
 630             r_add( &region[i_best_i], &region[i_best_j] );
 631
 632             if( i_best_j+1 < i_region )
 633                 memmove( &region[i_best_j], &region[i_best_j+1], sizeof(*region) * ( i_region - (i_best_j+1)  ) );
 634             i_region--;
 635         }
 636     }
 637
 638     /* */
 639     for( int n = 0; n < i_region; n++ )
 640         p_region[n] = region[n];
 641
 642 #ifdef DEBUG_REGION
 643     int64_t i_ck_time = mdate() - i_ck_start;
 644     msg_Err( p_spu, "ASS: %d objects merged into %d region in %d micros", i_count, i_region, (int)(i_ck_time) );
 645 #endif
 646
 647     free( pp_img );
 648
 649     return i_region;
 650 }
 651
 652 static void RegionDraw( subpicture_region_t *p_region, ASS_Image *p_img )
 653 {
 654     const plane_t *p = &p_region->p_picture->p[0];
 655     const int i_x = p_region->i_x;
 656     const int i_y = p_region->i_y;
 657     const int i_width  = p_region->fmt.i_width;
 658     const int i_height = p_region->fmt.i_height;
 659
 660     memset( p->p_pixels, 0x00, p->i_pitch * p->i_lines );
 661     for( ; p_img != NULL; p_img = p_img->next )
 662     {
 663         if( p_img->dst_x < i_x || p_img->dst_x + p_img->w > i_x + i_width ||
 664             p_img->dst_y < i_y || p_img->dst_y + p_img->h > i_y + i_height )
 665             continue;
 666
 667         const unsigned r = (p_img->color >> 24)&0xff;
 668         const unsigned g = (p_img->color >> 16)&0xff;
 669         const unsigned b = (p_img->color >>  8)&0xff;
 670         const unsigned a = (p_img->color      )&0xff;
 671         int x, y;
 672
 673         for( y = 0; y < p_img->h; y++ )
 674         {
 675             for( x = 0; x < p_img->w; x++ )
 676             {
 677                 const unsigned alpha = p_img->bitmap[y*p_img->stride+x];
 678                 const unsigned an = (255 - a) * alpha / 255;
 679
 680                 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)];
 681                 const unsigned ao = p_rgba[3];
 682
 683                 /* Native endianness, but RGBA ordering */
 684                 if( ao == 0 )
 685                 {
 686                     /* Optimized but the else{} will produce the same result */
 687                     p_rgba[0] = r;
 688                     p_rgba[1] = g;
 689                     p_rgba[2] = b;
 690                     p_rgba[3] = an;
 691                 }
 692                 else
 693                 {
 694                     p_rgba[3] = 255 - ( 255 - p_rgba[3] ) * ( 255 - an ) / 255;
 695                     if( p_rgba[3] != 0 )
 696                     {
 697                         p_rgba[0] = ( p_rgba[0] * ao * (255-an) / 255 + r * an ) / p_rgba[3];
 698                         p_rgba[1] = ( p_rgba[1] * ao * (255-an) / 255 + g * an ) / p_rgba[3];
 699                         p_rgba[2] = ( p_rgba[2] * ao * (255-an) / 255 + b * an ) / p_rgba[3];
 700                     }
 701                 }
 702             }
 703         }
 704     }
 705
 706 #ifdef DEBUG_REGION
 707     /* XXX Draw a box for debug */
 708 #define P(x,y) ((uint32_t*)&p->p_pixels[(y)*p->i_pitch + 4*(x)])
 709     for( int y = 0; y < p->i_lines; y++ )
 710         *P(0,y) = *P(p->i_visible_pitch/4-1,y) = 0xff000000;
 711     for( int x = 0; x < p->i_visible_pitch; x++ )
 712         *P(x/4,0) = *P(x/4,p->i_visible_lines-1) = 0xff000000;
 713 #undef P
 714 #endif
 715 }
 716