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 LIBASS_VERSION < 0x01300000
  46 # define ASS_FONTPROVIDER_AUTODETECT 1
  47 #endif
  48
  49 #if defined(_WIN32)
  50 #   include <vlc_charset.h>
  51 #endif
  52
  53 /*****************************************************************************
  54  * Module descriptor
  55  *****************************************************************************/
  56 static int  Create ( vlc_object_t * );
  57 static void Destroy( vlc_object_t * );
  58
  59 vlc_module_begin ()
  60     set_shortname( N_("Subtitles (advanced)"))
  61     set_description( N_("Subtitle renderers using libass") )
  62     set_capability( "spu decoder", 100 )
  63     set_category( CAT_INPUT )
  64     set_subcategory( SUBCAT_INPUT_SCODEC )
  65     set_callbacks( Create, Destroy )
  66 vlc_module_end ()
  67
  68 /*****************************************************************************
  69  * Local prototypes
  70  *****************************************************************************/
  71 static int DecodeBlock( decoder_t *, block_t * );
  72 static void Flush( decoder_t * );
  73
  74 /* */
  75 typedef struct
  76 {
  77     vlc_tick_t     i_max_stop;
  78
  79     /* The following fields of decoder_sys_t are shared between decoder and spu units */
  80     vlc_mutex_t    lock;
  81     int            i_refcount;
  82
  83     /* */
  84     ASS_Library    *p_library;
  85     ASS_Renderer   *p_renderer;
  86     video_format_t fmt;
  87
  88     /* */
  89     ASS_Track      *p_track;
  90 } decoder_sys_t;
  91 static void DecSysRelease( decoder_sys_t *p_sys );
  92 static void DecSysHold( decoder_sys_t *p_sys );
  93
  94 /* */
  95 static int SubpictureValidate( subpicture_t *,
  96                                bool, const video_format_t *,
  97                                bool, const video_format_t *,
  98                                vlc_tick_t );
  99 static void SubpictureUpdate( subpicture_t *,
 100                               const video_format_t *,
 101                               const video_format_t *,
 102                               vlc_tick_t );
 103 static void SubpictureDestroy( subpicture_t * );
 104
 105 typedef struct
 106 {
 107     decoder_sys_t *p_dec_sys;
 108     void          *p_subs_data;
 109     int           i_subs_len;
 110     vlc_tick_t    i_pts;
 111
 112     ASS_Image     *p_img;
 113 } libass_spu_updater_sys_t;
 114
 115 typedef struct
 116 {
 117     int x0;
 118     int y0;
 119     int x1;
 120     int y1;
 121 } rectangle_t;
 122
 123 static int BuildRegions( rectangle_t *p_region, int i_max_region, ASS_Image *p_img_list, int i_width, int i_height );
 124 static void RegionDraw( subpicture_region_t *p_region, ASS_Image *p_img );
 125
 126 //#define DEBUG_REGION
 127
 128 /*****************************************************************************
 129  * Create: Open libass decoder.
 130  *****************************************************************************/
 131 static int Create( vlc_object_t *p_this )
 132 {
 133     decoder_t *p_dec = (decoder_t *)p_this;
 134     decoder_sys_t *p_sys;
 135
 136     if( p_dec->fmt_in.i_codec != VLC_CODEC_SSA )
 137         return VLC_EGENERIC;
 138
 139     p_dec->pf_decode = DecodeBlock;
 140     p_dec->pf_flush  = Flush;
 141
 142     p_dec->p_sys = p_sys = malloc( sizeof( decoder_sys_t ) );
 143     if( !p_sys )
 144         return VLC_ENOMEM;
 145
 146     /* */
 147     vlc_mutex_init( &p_sys->lock );
 148     p_sys->i_refcount = 1;
 149     memset( &p_sys->fmt, 0, sizeof(p_sys->fmt) );
 150     p_sys->i_max_stop = VLC_TICK_INVALID;
 151     p_sys->p_library  = NULL;
 152     p_sys->p_renderer = NULL;
 153     p_sys->p_track    = NULL;
 154
 155     /* Create libass library */
 156     ASS_Library *p_library = p_sys->p_library = ass_library_init();
 157     if( !p_library )
 158     {
 159         msg_Warn( p_dec, "Libass library creation failed" );
 160         DecSysRelease( p_sys );
 161         return VLC_EGENERIC;
 162     }
 163
 164     /* load attachments */
 165     input_attachment_t  **pp_attachments;
 166     int                   i_attachments;
 167     if( decoder_GetInputAttachments( p_dec, &pp_attachments, &i_attachments ))
 168     {
 169         i_attachments = 0;
 170         pp_attachments = NULL;
 171     }
 172     for( int k = 0; k < i_attachments; k++ )
 173     {
 174         input_attachment_t *p_attach = pp_attachments[k];
 175
 176         bool found = false;
 177
 178         /* Check mimetype*/
 179         if( !strcasecmp( p_attach->psz_mime, "application/x-truetype-font" ) )
 180             found = true;
 181         /* Then extension */
 182         else if( !found && strlen( p_attach->psz_name ) > 4 )
 183         {
 184             char *ext = p_attach->psz_name + strlen( p_attach->psz_name ) - 4;
 185
 186             if( !strcasecmp( ext, ".ttf" ) || !strcasecmp( ext, ".otf" ) || !strcasecmp( ext, ".ttc" ) )
 187                 found = true;
 188         }
 189
 190         if( found )
 191         {
 192             msg_Dbg( p_dec, "adding embedded font %s", p_attach->psz_name );
 193
 194             ass_add_font( p_sys->p_library, p_attach->psz_name, p_attach->p_data, p_attach->i_data );
 195         }
 196         vlc_input_attachment_Delete( p_attach );
 197     }
 198     free( pp_attachments );
 199
 200     ass_set_extract_fonts( p_library, true );
 201     ass_set_style_overrides( p_library, NULL );
 202
 203     /* Create the renderer */
 204     ASS_Renderer *p_renderer = p_sys->p_renderer = ass_renderer_init( p_library );
 205     if( !p_renderer )
 206     {
 207         msg_Warn( p_dec, "Libass renderer creation failed" );
 208         DecSysRelease( p_sys );
 209         return VLC_EGENERIC;
 210     }
 211
 212     ass_set_use_margins( p_renderer, false);
 213     //if( false )
 214     //    ass_set_margins( p_renderer, int t, int b, int l, int r);
 215     ass_set_font_scale( p_renderer, 1.0 );
 216     ass_set_line_spacing( p_renderer, 0.0 );
 217
 218 #if defined( __ANDROID__ )
 219     const char *psz_font, *psz_family;
 220     const char *psz_font_droid = "/system/fonts/DroidSans-Bold.ttf";
 221     const char *psz_family_droid = "Droid Sans Bold";
 222     const char *psz_font_noto = "/system/fonts/NotoSansCJK-Regular.ttc";
 223     const char *psz_family_noto = "Noto Sans";
 224
 225     // Workaround for Android 5.0+, since libass doesn't parse the XML yet
 226     if( access( psz_font_noto, R_OK ) != -1 )
 227     {
 228         psz_font = psz_font_noto;
 229         psz_family = psz_family_noto;
 230     }
 231     else
 232     {
 233         psz_font = psz_font_droid;
 234         psz_family = psz_family_droid;
 235     }
 236
 237 #elif defined( __APPLE__ )
 238     const char *psz_font = NULL; /* We don't ship a default font with VLC */
 239     const char *psz_family = "Helvetica Neue"; /* Use HN if we can't find anything more suitable - Arial is not on all Apple platforms */
 240 #else
 241     const char *psz_font = NULL; /* We don't ship a default font with VLC */
 242     const char *psz_family = "Arial"; /* Use Arial if we can't find anything more suitable */
 243 #endif
 244
 245 #ifdef HAVE_FONTCONFIG
 246 #if defined(_WIN32)
 247     vlc_dialog_id *p_dialog_id =
 248         vlc_dialog_display_progress( p_dec, true, 0.0, NULL,
 249                                     _("Building font cache"),
 250                                     _( "Please wait while your font cache is rebuilt.\n"
 251                                     "This should take less than a minute." ) );
 252 #endif
 253     ass_set_fonts( p_renderer, psz_font, psz_family, ASS_FONTPROVIDER_AUTODETECT, NULL, 1 );  // setup default font/family
 254 #if defined(_WIN32)
 255     if( p_dialog_id != 0 )
 256         vlc_dialog_release( p_dec, p_dialog_id );
 257 #endif
 258 #else
 259     ass_set_fonts( p_renderer, psz_font, psz_family, ASS_FONTPROVIDER_AUTODETECT, NULL, 0 );
 260 #endif
 261
 262     /* Anything else than NONE will break smooth img updating.
 263        TODO: List and force ASS_HINTING_LIGHT for known problematic fonts */
 264     ass_set_hinting( p_renderer, ASS_HINTING_NONE );
 265
 266     /* Add a track */
 267     ASS_Track *p_track = p_sys->p_track = ass_new_track( p_sys->p_library );
 268     if( !p_track )
 269     {
 270         DecSysRelease( p_sys );
 271         return VLC_EGENERIC;
 272     }
 273     ass_process_codec_private( p_track, p_dec->fmt_in.p_extra, p_dec->fmt_in.i_extra );
 274
 275     p_dec->fmt_out.i_codec = VLC_CODEC_RGBA;
 276
 277     return VLC_SUCCESS;
 278 }
 279
 280 /*****************************************************************************
 281  * Destroy: finish
 282  *****************************************************************************/
 283 static void Destroy( vlc_object_t *p_this )
 284 {
 285     decoder_t *p_dec = (decoder_t *)p_this;
 286
 287     DecSysRelease( p_dec->p_sys );
 288 }
 289
 290 static void DecSysHold( decoder_sys_t *p_sys )
 291 {
 292     vlc_mutex_lock( &p_sys->lock );
 293     p_sys->i_refcount++;
 294     vlc_mutex_unlock( &p_sys->lock );
 295 }
 296 static void DecSysRelease( decoder_sys_t *p_sys )
 297 {
 298     /* */
 299     vlc_mutex_lock( &p_sys->lock );
 300     p_sys->i_refcount--;
 301     if( p_sys->i_refcount > 0 )
 302     {
 303         vlc_mutex_unlock( &p_sys->lock );
 304         return;
 305     }
 306     vlc_mutex_unlock( &p_sys->lock );
 307     vlc_mutex_destroy( &p_sys->lock );
 308
 309     if( p_sys->p_track )
 310         ass_free_track( p_sys->p_track );
 311     if( p_sys->p_renderer )
 312         ass_renderer_done( p_sys->p_renderer );
 313     if( p_sys->p_library )
 314         ass_library_done( p_sys->p_library );
 315
 316     free( p_sys );
 317 }
 318
 319 /*****************************************************************************
 320  * Flush:
 321  *****************************************************************************/
 322 static void Flush( decoder_t *p_dec )
 323 {
 324     decoder_sys_t *p_sys = p_dec->p_sys;
 325
 326     p_sys->i_max_stop = VLC_TICK_INVALID;
 327 }
 328
 329 /****************************************************************************
 330  * DecodeBlock:
 331  ****************************************************************************/
 332 static int DecodeBlock( decoder_t *p_dec, block_t *p_block )
 333 {
 334     decoder_sys_t *p_sys = p_dec->p_sys;
 335
 336     subpicture_t *p_spu = NULL;
 337
 338     if( p_block == NULL ) /* No Drain */
 339         return VLCDEC_SUCCESS;
 340
 341     if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )
 342     {
 343         Flush( p_dec );
 344         block_Release( p_block );
 345         return VLCDEC_SUCCESS;
 346     }
 347
 348     if( p_block->i_buffer == 0 || p_block->p_buffer[0] == '\0' )
 349     {
 350         block_Release( p_block );
 351         return VLCDEC_SUCCESS;
 352     }
 353
 354     libass_spu_updater_sys_t *p_spu_sys = malloc( sizeof(*p_spu_sys) );
 355     if( !p_spu_sys )
 356     {
 357         block_Release( p_block );
 358         return VLCDEC_SUCCESS;
 359     }
 360
 361     subpicture_updater_t updater = {
 362         .pf_validate = SubpictureValidate,
 363         .pf_update   = SubpictureUpdate,
 364         .pf_destroy  = SubpictureDestroy,
 365         .p_sys       = p_spu_sys,
 366     };
 367     p_spu = decoder_NewSubpicture( p_dec, &updater );
 368     if( !p_spu )
 369     {
 370         msg_Warn( p_dec, "can't get spu buffer" );
 371         free( p_spu_sys );
 372         block_Release( p_block );
 373         return VLCDEC_SUCCESS;
 374     }
 375
 376     p_spu_sys->p_img = NULL;
 377     p_spu_sys->p_dec_sys = p_sys;
 378     p_spu_sys->i_subs_len = p_block->i_buffer;
 379     p_spu_sys->p_subs_data = malloc( p_block->i_buffer );
 380     p_spu_sys->i_pts = p_block->i_pts;
 381     if( !p_spu_sys->p_subs_data )
 382     {
 383         subpicture_Delete( p_spu );
 384         block_Release( p_block );
 385         return VLCDEC_SUCCESS;
 386     }
 387     memcpy( p_spu_sys->p_subs_data, p_block->p_buffer,
 388             p_block->i_buffer );
 389
 390     p_spu->i_start = p_block->i_pts;
 391     p_spu->i_stop = __MAX( p_sys->i_max_stop, p_block->i_pts + p_block->i_length );
 392     p_spu->b_ephemer = true;
 393     p_spu->b_absolute = true;
 394
 395     p_sys->i_max_stop = p_spu->i_stop;
 396
 397     vlc_mutex_lock( &p_sys->lock );
 398     if( p_sys->p_track )
 399     {
 400         ass_process_chunk( p_sys->p_track, p_spu_sys->p_subs_data, p_spu_sys->i_subs_len,
 401                            p_block->i_pts / 1000, p_block->i_length / 1000 );
 402     }
 403     vlc_mutex_unlock( &p_sys->lock );
 404
 405     DecSysHold( p_sys ); /* Keep a reference for the returned subpicture */
 406
 407     block_Release( p_block );
 408
 409     decoder_QueueSub( p_dec, p_spu );
 410     return VLCDEC_SUCCESS;
 411 }
 412
 413 /****************************************************************************
 414  *
 415  ****************************************************************************/
 416 static int SubpictureValidate( subpicture_t *p_subpic,
 417                                bool b_fmt_src, const video_format_t *p_fmt_src,
 418                                bool b_fmt_dst, const video_format_t *p_fmt_dst,
 419                                vlc_tick_t i_ts )
 420 {
 421     libass_spu_updater_sys_t *p_spusys = p_subpic->updater.p_sys;
 422     decoder_sys_t *p_sys = p_spusys->p_dec_sys;
 423
 424     vlc_mutex_lock( &p_sys->lock );
 425
 426     video_format_t fmt = *p_fmt_dst;
 427     fmt.i_chroma         = VLC_CODEC_RGBA;
 428     fmt.i_bits_per_pixel = 0;
 429     fmt.i_x_offset       = 0;
 430     fmt.i_y_offset       = 0;
 431     if( b_fmt_src || b_fmt_dst )
 432     {
 433         ass_set_frame_size( p_sys->p_renderer, fmt.i_visible_width, fmt.i_visible_height );
 434         const double src_ratio = (double)p_fmt_src->i_visible_width / p_fmt_src->i_visible_height;
 435         const double dst_ratio = (double)p_fmt_dst->i_visible_width / p_fmt_dst->i_visible_height;
 436         ass_set_aspect_ratio( p_sys->p_renderer, dst_ratio / src_ratio, 1 );
 437         p_sys->fmt = fmt;
 438     }
 439
 440     /* */
 441     const vlc_tick_t i_stream_date = p_spusys->i_pts + (i_ts - p_subpic->i_start);
 442     int i_changed;
 443     ASS_Image *p_img = ass_render_frame( p_sys->p_renderer, p_sys->p_track,
 444                                          i_stream_date/1000, &i_changed );
 445
 446     if( !i_changed && !b_fmt_src && !b_fmt_dst &&
 447         (p_img != NULL) == (p_subpic->p_region != NULL) )
 448     {
 449         vlc_mutex_unlock( &p_sys->lock );
 450         return VLC_SUCCESS;
 451     }
 452     p_spusys->p_img = p_img;
 453
 454     /* The lock is released by SubpictureUpdate */
 455     return VLC_EGENERIC;
 456 }
 457
 458 static void SubpictureUpdate( subpicture_t *p_subpic,
 459                               const video_format_t *p_fmt_src,
 460                               const video_format_t *p_fmt_dst,
 461                               vlc_tick_t i_ts )
 462 {
 463     VLC_UNUSED( p_fmt_src ); VLC_UNUSED( p_fmt_dst ); VLC_UNUSED( i_ts );
 464
 465     libass_spu_updater_sys_t *p_spusys = p_subpic->updater.p_sys;
 466     decoder_sys_t *p_sys = p_spusys->p_dec_sys;
 467
 468     video_format_t fmt = p_sys->fmt;
 469     ASS_Image *p_img = p_spusys->p_img;
 470
 471     /* */
 472     p_subpic->i_original_picture_height = fmt.i_visible_height;
 473     p_subpic->i_original_picture_width = fmt.i_visible_width;
 474
 475     /* XXX to improve efficiency we merge regions that are close minimizing
 476      * the lost surface.
 477      * libass tends to create a lot of small regions and thus spu engine
 478      * reinstanciate a lot the scaler, and as we do not support subpel blending
 479      * it looks ugly (text unaligned).
 480      */
 481     const int i_max_region = 4;
 482     rectangle_t region[i_max_region];
 483     const int i_region = BuildRegions( region, i_max_region, p_img, fmt.i_width, fmt.i_height );
 484
 485     if( i_region <= 0 )
 486     {
 487         vlc_mutex_unlock( &p_sys->lock );
 488         return;
 489     }
 490
 491     /* Allocate the regions and draw them */
 492     subpicture_region_t **pp_region_last = &p_subpic->p_region;
 493
 494     for( int i = 0; i < i_region; i++ )
 495     {
 496         subpicture_region_t *r;
 497         video_format_t fmt_region;
 498
 499         /* */
 500         fmt_region = fmt;
 501         fmt_region.i_width =
 502         fmt_region.i_visible_width  = region[i].x1 - region[i].x0;
 503         fmt_region.i_height =
 504         fmt_region.i_visible_height = region[i].y1 - region[i].y0;
 505
 506         r = subpicture_region_New( &fmt_region );
 507         if( !r )
 508             break;
 509         r->i_x = region[i].x0;
 510         r->i_y = region[i].y0;
 511         r->i_align = SUBPICTURE_ALIGN_TOP | SUBPICTURE_ALIGN_LEFT;
 512
 513         /* */
 514         RegionDraw( r, p_img );
 515
 516         /* */
 517         *pp_region_last = r;
 518         pp_region_last = &r->p_next;
 519     }
 520     vlc_mutex_unlock( &p_sys->lock );
 521
 522 }
 523 static void SubpictureDestroy( subpicture_t *p_subpic )
 524 {
 525     libass_spu_updater_sys_t *p_spusys = p_subpic->updater.p_sys;
 526
 527     DecSysRelease( p_spusys->p_dec_sys );
 528     free( p_spusys->p_subs_data );
 529     free( p_spusys );
 530 }
 531
 532 static rectangle_t r_create( int x0, int y0, int x1, int y1 )
 533 {
 534     rectangle_t r = { x0, y0, x1, y1 };
 535     return r;
 536 }
 537 static rectangle_t r_img( const ASS_Image *p_img )
 538 {
 539     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 );
 540 }
 541 static void r_add( rectangle_t *r, const rectangle_t *n )
 542 {
 543     r->x0 = __MIN( r->x0, n->x0 );
 544     r->y0 = __MIN( r->y0, n->y0 );
 545     r->x1 = __MAX( r->x1, n->x1 );
 546     r->y1 = __MAX( r->y1, n->y1 );
 547 }
 548 static int r_surface( const rectangle_t *r )
 549 {
 550     return (r->x1-r->x0) * (r->y1-r->y0);
 551 }
 552 static bool r_overlap( const rectangle_t *a, const rectangle_t *b, int i_dx, int i_dy )
 553 {
 554     return  __MAX(a->x0-i_dx, b->x0) < __MIN( a->x1+i_dx, b->x1 ) &&
 555             __MAX(a->y0-i_dy, b->y0) < __MIN( a->y1+i_dy, b->y1 );
 556 }
 557
 558 static int BuildRegions( rectangle_t *p_region, int i_max_region, ASS_Image *p_img_list, int i_width, int i_height )
 559 {
 560     ASS_Image *p_tmp;
 561     int i_count;
 562
 563 #ifdef DEBUG_REGION
 564     int64_t i_ck_start = vlc_tick_now();
 565 #endif
 566
 567     for( p_tmp = p_img_list, i_count = 0; p_tmp != NULL; p_tmp = p_tmp->next )
 568         if( p_tmp->w > 0 && p_tmp->h > 0 )
 569             i_count++;
 570     if( i_count <= 0 )
 571         return 0;
 572
 573     ASS_Image **pp_img = calloc( i_count, sizeof(*pp_img) );
 574     if( !pp_img )
 575         return 0;
 576
 577     for( p_tmp = p_img_list, i_count = 0; p_tmp != NULL; p_tmp = p_tmp->next )
 578         if( p_tmp->w > 0 && p_tmp->h > 0 )
 579             pp_img[i_count++] = p_tmp;
 580
 581     /* */
 582     const int i_w_inc = __MAX( ( i_width + 49 ) / 50, 32 );
 583     const int i_h_inc = __MAX( ( i_height + 99 ) / 100, 32 );
 584     int i_maxh = i_w_inc;
 585     int i_maxw = i_h_inc;
 586     int i_region;
 587     rectangle_t region[i_max_region+1];
 588
 589     i_region = 0;
 590     for( int i_used = 0; i_used < i_count; )
 591     {
 592         int n;
 593         for( n = 0; n < i_count; n++ )
 594         {
 595             if( pp_img[n] )
 596                 break;
 597         }
 598         assert( i_region < i_max_region + 1 );
 599         region[i_region++] = r_img( pp_img[n] );
 600         pp_img[n] = NULL; i_used++;
 601
 602         bool b_ok;
 603         do {
 604             b_ok = false;
 605             for( n = 0; n < i_count; n++ )
 606             {
 607                 ASS_Image *p_img = pp_img[n];
 608                 if( !p_img )
 609                     continue;
 610                 rectangle_t r = r_img( p_img );
 611
 612                 int k;
 613                 int i_best = -1;
 614                 int i_best_s = INT_MAX;
 615                 for( k = 0; k < i_region; k++ )
 616                 {
 617                     if( !r_overlap( &region[k], &r, i_maxw, i_maxh ) )
 618                         continue;
 619                     int s = r_surface( &r );
 620                     if( s < i_best_s )
 621                     {
 622                         i_best_s = s;
 623                         i_best = k;
 624                     }
 625                 }
 626                 if( i_best >= 0 )
 627                 {
 628                     r_add( &region[i_best], &r );
 629                     pp_img[n] = NULL; i_used++;
 630                     b_ok = true;
 631                 }
 632             }
 633         } while( b_ok );
 634
 635         if( i_region > i_max_region )
 636         {
 637             int i_best_i = -1;
 638             int i_best_j = -1;
 639             int i_best_ds = INT_MAX;
 640
 641             /* merge best */
 642             for( int i = 0; i < i_region; i++ )
 643             {
 644                 for( int j = i+1; j < i_region; j++ )
 645                 {
 646                     rectangle_t rect = region[i];
 647                     r_add( &rect, &region[j] );
 648                     int ds = r_surface( &rect ) - r_surface( &region[i] ) - r_surface( &region[j] );
 649
 650                     if( ds < i_best_ds )
 651                     {
 652                         i_best_i = i;
 653                         i_best_j = j;
 654                         i_best_ds = ds;
 655                     }
 656                 }
 657             }
 658 #ifdef DEBUG_REGION
 659             msg_Err( p_spu, "Merging %d and %d", i_best_i, i_best_j );
 660 #endif
 661             if( i_best_j >= 0 && i_best_i >= 0 )
 662             {
 663                 r_add( &region[i_best_i], &region[i_best_j] );
 664
 665                 if( i_best_j+1 < i_region )
 666                     memmove( &region[i_best_j], &region[i_best_j+1], sizeof(*region) * ( i_region - (i_best_j+1)  ) );
 667                 i_region--;
 668             }
 669         }
 670     }
 671
 672     /* */
 673     for( int n = 0; n < i_region; n++ )
 674         p_region[n] = region[n];
 675
 676 #ifdef DEBUG_REGION
 677     int64_t i_ck_time = vlc_tick_now() - i_ck_start;
 678     msg_Err( p_spu, "ASS: %d objects merged into %d region in %d micros", i_count, i_region, (int)(i_ck_time) );
 679 #endif
 680
 681     free( pp_img );
 682
 683     return i_region;
 684 }
 685
 686 static void RegionDraw( subpicture_region_t *p_region, ASS_Image *p_img )
 687 {
 688     const plane_t *p = &p_region->p_picture->p[0];
 689     const int i_x = p_region->i_x;
 690     const int i_y = p_region->i_y;
 691     const int i_width  = p_region->fmt.i_width;
 692     const int i_height = p_region->fmt.i_height;
 693
 694     memset( p->p_pixels, 0x00, p->i_pitch * p->i_lines );
 695     for( ; p_img != NULL; p_img = p_img->next )
 696     {
 697         if( p_img->dst_x < i_x || p_img->dst_x + p_img->w > i_x + i_width ||
 698             p_img->dst_y < i_y || p_img->dst_y + p_img->h > i_y + i_height )
 699             continue;
 700
 701         const unsigned r = (p_img->color >> 24)&0xff;
 702         const unsigned g = (p_img->color >> 16)&0xff;
 703         const unsigned b = (p_img->color >>  8)&0xff;
 704         const unsigned a = (p_img->color      )&0xff;
 705         int x, y;
 706
 707         for( y = 0; y < p_img->h; y++ )
 708         {
 709             for( x = 0; x < p_img->w; x++ )
 710             {
 711                 const unsigned alpha = p_img->bitmap[y*p_img->stride+x];
 712                 const unsigned an = (255 - a) * alpha / 255;
 713
 714                 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)];
 715                 const unsigned ao = p_rgba[3];
 716
 717                 /* Native endianness, but RGBA ordering */
 718                 if( ao == 0 )
 719                 {
 720                     /* Optimized but the else{} will produce the same result */
 721                     p_rgba[0] = r;
 722                     p_rgba[1] = g;
 723                     p_rgba[2] = b;
 724                     p_rgba[3] = an;
 725                 }
 726                 else
 727                 {
 728                     p_rgba[3] = 255 - ( 255 - p_rgba[3] ) * ( 255 - an ) / 255;
 729                     if( p_rgba[3] != 0 )
 730                     {
 731                         p_rgba[0] = ( p_rgba[0] * ao * (255-an) / 255 + r * an ) / p_rgba[3];
 732                         p_rgba[1] = ( p_rgba[1] * ao * (255-an) / 255 + g * an ) / p_rgba[3];
 733                         p_rgba[2] = ( p_rgba[2] * ao * (255-an) / 255 + b * an ) / p_rgba[3];
 734                     }
 735                 }
 736             }
 737         }
 738     }
 739
 740 #ifdef DEBUG_REGION
 741     /* XXX Draw a box for debug */
 742 #define P(x,y) ((uint32_t*)&p->p_pixels[(y)*p->i_pitch + 4*(x)])
 743     for( int y = 0; y < p->i_lines; y++ )
 744         *P(0,y) = *P(p->i_visible_pitch/4-1,y) = 0xff000000;
 745     for( int x = 0; x < p->i_visible_pitch; x++ )
 746         *P(x/4,0) = *P(x/4,p->i_visible_lines-1) = 0xff000000;
 747 #undef P
 748 #endif
 749 }
 750