git.sesse.net Git - vlc/blob - modules/codec/spudec/parse.c

   1 /*****************************************************************************
   2  * parse.c: SPU parser
   3  *****************************************************************************
   4  * Copyright (C) 2000-2001, 2005, 2006 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Sam Hocevar <sam@zoy.org>
   8  *          Laurent Aimar <fenrir@via.ecp.fr>
   9  *          Gildas Bazin <gbazin@videolan.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29 #include <vlc/vlc.h>
  30 #include <vlc/vout.h>
  31 #include <vlc/decoder.h>
  32
  33 #include "spudec.h"
  34
  35 /*****************************************************************************
  36  * Local prototypes.
  37  *****************************************************************************/
  38 static int  ParseControlSeq( decoder_t *, subpicture_t *, subpicture_data_t *);
  39 static int  ParseRLE       ( decoder_t *, subpicture_t *, subpicture_data_t *);
  40 static void Render         ( decoder_t *, subpicture_t *, subpicture_data_t *);
  41
  42 /*****************************************************************************
  43  * AddNibble: read a nibble from a source packet and add it to our integer.
  44  *****************************************************************************/
  45 static inline unsigned int AddNibble( unsigned int i_code,
  46                                       uint8_t *p_src, unsigned int *pi_index )
  47 {
  48     if( *pi_index & 0x1 )
  49     {
  50         return( i_code << 4 | ( p_src[(*pi_index)++ >> 1] & 0xf ) );
  51     }
  52     else
  53     {
  54         return( i_code << 4 | p_src[(*pi_index)++ >> 1] >> 4 );
  55     }
  56 }
  57
  58 /*****************************************************************************
  59  * ParsePacket: parse an SPU packet and send it to the video output
  60  *****************************************************************************
  61  * This function parses the SPU packet and, if valid, sends it to the
  62  * video output.
  63  *****************************************************************************/
  64 subpicture_t * E_(ParsePacket)( decoder_t *p_dec )
  65 {
  66     decoder_sys_t *p_sys = p_dec->p_sys;
  67     subpicture_data_t *p_spu_data;
  68     subpicture_t *p_spu;
  69
  70     /* Allocate the subpicture internal data. */
  71     p_spu = p_dec->pf_spu_buffer_new( p_dec );
  72     if( !p_spu ) return NULL;
  73
  74     p_spu->b_pausable = VLC_TRUE;
  75
  76     /* Rationale for the "p_spudec->i_rle_size * 4": we are going to
  77      * expand the RLE stuff so that we won't need to read nibbles later
  78      * on. This will speed things up a lot. Plus, we'll only need to do
  79      * this stupid interlacing stuff once. */
  80     p_spu_data = malloc( sizeof(subpicture_data_t) + 4 * p_sys->i_rle_size );
  81     p_spu_data->p_data = (uint8_t *)p_spu_data + sizeof(subpicture_data_t);
  82     p_spu_data->b_palette = VLC_FALSE;
  83     p_spu_data->b_auto_crop = VLC_FALSE;
  84     p_spu_data->i_y_top_offset = 0;
  85     p_spu_data->i_y_bottom_offset = 0;
  86
  87     p_spu_data->pi_alpha[0] = 0x00;
  88     p_spu_data->pi_alpha[1] = 0x0f;
  89     p_spu_data->pi_alpha[2] = 0x0f;
  90     p_spu_data->pi_alpha[3] = 0x0f;
  91
  92     /* Get display time now. If we do it later, we may miss the PTS. */
  93     p_spu_data->i_pts = p_sys->i_pts;
  94
  95     p_spu->i_original_picture_width =
  96         p_dec->fmt_in.subs.spu.i_original_frame_width;
  97     p_spu->i_original_picture_height =
  98         p_dec->fmt_in.subs.spu.i_original_frame_height;
  99
 100     /* Getting the control part */
 101     if( ParseControlSeq( p_dec, p_spu, p_spu_data ) )
 102     {
 103         /* There was a parse error, delete the subpicture */
 104         p_dec->pf_spu_buffer_del( p_dec, p_spu );
 105         return NULL;
 106     }
 107
 108     /* We try to display it */
 109     if( ParseRLE( p_dec, p_spu, p_spu_data ) )
 110     {
 111         /* There was a parse error, delete the subpicture */
 112         p_dec->pf_spu_buffer_del( p_dec, p_spu );
 113         return NULL;
 114     }
 115
 116 #ifdef DEBUG_SPUDEC
 117     msg_Dbg( p_dec, "total size: 0x%x, RLE offsets: 0x%x 0x%x",
 118              p_sys->i_spu_size,
 119              p_spu_data->pi_offset[0], p_spu_data->pi_offset[1] );
 120 #endif
 121
 122     Render( p_dec, p_spu, p_spu_data );
 123     free( p_spu_data );
 124
 125     return p_spu;
 126 }
 127
 128 /*****************************************************************************
 129  * ParseControlSeq: parse all SPU control sequences
 130  *****************************************************************************
 131  * This is the most important part in SPU decoding. We get dates, palette
 132  * information, coordinates, and so on. For more information on the
 133  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 134  *****************************************************************************/
 135 static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
 136                             subpicture_data_t *p_spu_data )
 137 {
 138     decoder_sys_t *p_sys = p_dec->p_sys;
 139
 140     /* Our current index in the SPU packet */
 141     unsigned int i_index = p_sys->i_rle_size + 4;
 142
 143     /* The next start-of-control-sequence index and the previous one */
 144     unsigned int i_next_seq = 0, i_cur_seq = 0;
 145
 146     /* Command and date */
 147     uint8_t i_command = SPU_CMD_END;
 148     mtime_t date = 0;
 149
 150     /* Initialize the structure */
 151     p_spu->i_start = p_spu->i_stop = 0;
 152     p_spu->b_ephemer = VLC_FALSE;
 153
 154     for( i_index = 4 + p_sys->i_rle_size; i_index < p_sys->i_spu_size ; )
 155     {
 156         /* If we just read a command sequence, read the next one;
 157          * otherwise, go on with the commands of the current sequence. */
 158         if( i_command == SPU_CMD_END )
 159         {
 160             if( i_index + 4 > p_sys->i_spu_size )
 161             {
 162                 msg_Err( p_dec, "overflow in SPU command sequence" );
 163                 return VLC_EGENERIC;
 164             }
 165
 166             /* Get the control sequence date */
 167             date = (mtime_t)GetWBE( &p_sys->buffer[i_index] ) * 11000;
 168             /* FIXME How to access i_rate
 169                     * p_spudec->bit_stream.p_pes->i_rate / DEFAULT_RATE;
 170             */
 171
 172             /* Next offset */
 173             i_cur_seq = i_index;
 174             i_next_seq = GetWBE( &p_sys->buffer[i_index+2] );
 175
 176             if( i_next_seq > p_sys->i_spu_size )
 177             {
 178                 msg_Err( p_dec, "overflow in SPU next command sequence" );
 179                 return VLC_EGENERIC;
 180             }
 181
 182             /* Skip what we just read */
 183             i_index += 4;
 184         }
 185
 186         i_command = p_sys->buffer[i_index];
 187
 188         switch( i_command )
 189         {
 190         case SPU_CMD_FORCE_DISPLAY: /* 00 (force displaying) */
 191             p_spu->i_start = p_spu_data->i_pts + date;
 192             p_spu->b_ephemer = VLC_TRUE;
 193             i_index += 1;
 194             break;
 195
 196         /* Convert the dates in seconds to PTS values */
 197         case SPU_CMD_START_DISPLAY: /* 01 (start displaying) */
 198             p_spu->i_start = p_spu_data->i_pts + date;
 199             i_index += 1;
 200             break;
 201
 202         case SPU_CMD_STOP_DISPLAY: /* 02 (stop displaying) */
 203             p_spu->i_stop = p_spu_data->i_pts + date;
 204             i_index += 1;
 205             break;
 206
 207         case SPU_CMD_SET_PALETTE:
 208
 209             /* 03xxxx (palette) */
 210             if( i_index + 3 > p_sys->i_spu_size )
 211             {
 212                 msg_Err( p_dec, "overflow in SPU command" );
 213                 return VLC_EGENERIC;
 214             }
 215
 216             if( p_dec->fmt_in.subs.spu.palette[0] == 0xBeeF )
 217             {
 218                 unsigned int idx[4];
 219                 int i;
 220
 221                 p_spu_data->b_palette = VLC_TRUE;
 222
 223                 idx[0] = (p_sys->buffer[i_index+1]>>4)&0x0f;
 224                 idx[1] = (p_sys->buffer[i_index+1])&0x0f;
 225                 idx[2] = (p_sys->buffer[i_index+2]>>4)&0x0f;
 226                 idx[3] = (p_sys->buffer[i_index+2])&0x0f;
 227
 228                 for( i = 0; i < 4 ; i++ )
 229                 {
 230                     uint32_t i_color = p_dec->fmt_in.subs.spu.palette[1+idx[i]];
 231
 232                     /* FIXME: this job should be done sooner */
 233                     p_spu_data->pi_yuv[3-i][0] = (i_color>>16) & 0xff;
 234                     p_spu_data->pi_yuv[3-i][1] = (i_color>>0) & 0xff;
 235                     p_spu_data->pi_yuv[3-i][2] = (i_color>>8) & 0xff;
 236                 }
 237             }
 238
 239             i_index += 3;
 240             break;
 241
 242         case SPU_CMD_SET_ALPHACHANNEL: /* 04xxxx (alpha channel) */
 243             if( i_index + 3 > p_sys->i_spu_size )
 244             {
 245                 msg_Err( p_dec, "overflow in SPU command" );
 246                 return VLC_EGENERIC;
 247             }
 248
 249             p_spu_data->pi_alpha[3] = (p_sys->buffer[i_index+1]>>4)&0x0f;
 250             p_spu_data->pi_alpha[2] = (p_sys->buffer[i_index+1])&0x0f;
 251             p_spu_data->pi_alpha[1] = (p_sys->buffer[i_index+2]>>4)&0x0f;
 252             p_spu_data->pi_alpha[0] = (p_sys->buffer[i_index+2])&0x0f;
 253
 254             i_index += 3;
 255             break;
 256
 257         case SPU_CMD_SET_COORDINATES: /* 05xxxyyyxxxyyy (coordinates) */
 258             if( i_index + 7 > p_sys->i_spu_size )
 259             {
 260                 msg_Err( p_dec, "overflow in SPU command" );
 261                 return VLC_EGENERIC;
 262             }
 263
 264             p_spu->i_x = (p_sys->buffer[i_index+1]<<4)|
 265                          ((p_sys->buffer[i_index+2]>>4)&0x0f);
 266             p_spu->i_width = (((p_sys->buffer[i_index+2]&0x0f)<<8)|
 267                               p_sys->buffer[i_index+3]) - p_spu->i_x + 1;
 268
 269             p_spu->i_y = (p_sys->buffer[i_index+4]<<4)|
 270                          ((p_sys->buffer[i_index+5]>>4)&0x0f);
 271             p_spu->i_height = (((p_sys->buffer[i_index+5]&0x0f)<<8)|
 272                               p_sys->buffer[i_index+6]) - p_spu->i_y + 1;
 273
 274             /* Auto crop fullscreen subtitles */
 275             if( p_spu->i_height > 250 )
 276                 p_spu_data->b_auto_crop = VLC_TRUE;
 277
 278             i_index += 7;
 279             break;
 280
 281         case SPU_CMD_SET_OFFSETS: /* 06xxxxyyyy (byte offsets) */
 282             if( i_index + 5 > p_sys->i_spu_size )
 283             {
 284                 msg_Err( p_dec, "overflow in SPU command" );
 285                 return VLC_EGENERIC;
 286             }
 287
 288             p_spu_data->pi_offset[0] = GetWBE(&p_sys->buffer[i_index+1]) - 4;
 289             p_spu_data->pi_offset[1] = GetWBE(&p_sys->buffer[i_index+3]) - 4;
 290             i_index += 5;
 291             break;
 292
 293         case SPU_CMD_END: /* ff (end) */
 294             i_index += 1;
 295             break;
 296
 297         default: /* xx (unknown command) */
 298             msg_Warn( p_dec, "unknown SPU command 0x%.2x", i_command );
 299             if( i_index + 1 < i_next_seq )
 300             {
 301                  /* There is at least one other command sequence */
 302                  if( p_sys->buffer[i_next_seq - 1] == SPU_CMD_END )
 303                  {
 304                      /* This is consistent. Skip to that command sequence. */
 305                      i_index = i_next_seq;
 306                  }
 307                  else
 308                  {
 309                      /* There were other commands. */
 310                      msg_Warn( p_dec, "cannot recover, dropping subtitle" );
 311                      return VLC_EGENERIC;
 312                  }
 313             }
 314             else
 315             {
 316                 /* We were in the last command sequence. Stop parsing by
 317                  * pretending we met an SPU_CMD_END command. */
 318                 i_command = SPU_CMD_END;
 319                 i_index++;
 320             }
 321         }
 322
 323         /* We need to check for quit commands here */
 324         if( p_dec->b_die )
 325         {
 326             return VLC_EGENERIC;
 327         }
 328
 329         if( i_command == SPU_CMD_END && i_index != i_next_seq )
 330         {
 331             break;
 332         }
 333     }
 334
 335     /* Check that the next sequence index matches the current one */
 336     if( i_next_seq != i_cur_seq )
 337     {
 338         msg_Err( p_dec, "index mismatch (0x%.4x != 0x%.4x)",
 339                  i_next_seq, i_cur_seq );
 340         return VLC_EGENERIC;
 341     }
 342
 343     if( i_index > p_sys->i_spu_size )
 344     {
 345         msg_Err( p_dec, "uh-oh, we went too far (0x%.4x > 0x%.4x)",
 346                  i_index, p_sys->i_spu_size );
 347         return VLC_EGENERIC;
 348     }
 349
 350     if( !p_spu->i_start )
 351     {
 352         msg_Err( p_dec, "no `start display' command" );
 353     }
 354
 355     if( p_spu->i_stop <= p_spu->i_start && !p_spu->b_ephemer )
 356     {
 357         /* This subtitle will live for 5 seconds or until the next subtitle */
 358         p_spu->i_stop = p_spu->i_start + (mtime_t)500 * 11000;
 359         p_spu->b_ephemer = VLC_TRUE;
 360     }
 361
 362     /* Get rid of padding bytes */
 363     if( p_sys->i_spu_size > i_index + 1 )
 364     {
 365         /* Zero or one padding byte are quite usual
 366          * More than one padding byte - this is very strange, but
 367          * we can ignore them. */
 368         msg_Warn( p_dec, "%i padding bytes, we usually get 0 or 1 of them",
 369                   p_sys->i_spu_size - i_index );
 370     }
 371
 372     /* Successfully parsed ! */
 373     return VLC_SUCCESS;
 374 }
 375
 376 /*****************************************************************************
 377  * ParseRLE: parse the RLE part of the subtitle
 378  *****************************************************************************
 379  * This part parses the subtitle graphical data and stores it in a more
 380  * convenient structure for later decoding. For more information on the
 381  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 382  *****************************************************************************/
 383 static int ParseRLE( decoder_t *p_dec, subpicture_t * p_spu,
 384                      subpicture_data_t *p_spu_data )
 385 {
 386     decoder_sys_t *p_sys = p_dec->p_sys;
 387     uint8_t       *p_src = &p_sys->buffer[4];
 388
 389     unsigned int i_code;
 390
 391     unsigned int i_width = p_spu->i_width;
 392     unsigned int i_height = p_spu->i_height;
 393     unsigned int i_x, i_y;
 394
 395     uint16_t *p_dest = (uint16_t *)p_spu_data->p_data;
 396
 397     /* The subtitles are interlaced, we need two offsets */
 398     unsigned int  i_id = 0;                   /* Start on the even SPU layer */
 399     unsigned int  pi_table[ 2 ];
 400     unsigned int *pi_offset;
 401
 402     /* Cropping */
 403     vlc_bool_t b_empty_top = VLC_TRUE;
 404     unsigned int i_skipped_top = 0, i_skipped_bottom = 0;
 405     unsigned int i_transparent_code = 0;
 406
 407     /* Colormap statistics */
 408     int i_border = -1;
 409     int stats[4]; stats[0] = stats[1] = stats[2] = stats[3] = 0;
 410
 411     pi_table[ 0 ] = p_spu_data->pi_offset[ 0 ] << 1;
 412     pi_table[ 1 ] = p_spu_data->pi_offset[ 1 ] << 1;
 413
 414     for( i_y = 0 ; i_y < i_height ; i_y++ )
 415     {
 416         pi_offset = pi_table + i_id;
 417
 418         for( i_x = 0 ; i_x < i_width ; i_x += i_code >> 2 )
 419         {
 420             i_code = AddNibble( 0, p_src, pi_offset );
 421
 422             if( i_code < 0x04 )
 423             {
 424                 i_code = AddNibble( i_code, p_src, pi_offset );
 425
 426                 if( i_code < 0x10 )
 427                 {
 428                     i_code = AddNibble( i_code, p_src, pi_offset );
 429
 430                     if( i_code < 0x040 )
 431                     {
 432                         i_code = AddNibble( i_code, p_src, pi_offset );
 433
 434                         if( i_code < 0x0100 )
 435                         {
 436                             /* If the 14 first bits are set to 0, then it's a
 437                              * new line. We emulate it. */
 438                             if( i_code < 0x0004 )
 439                             {
 440                                 i_code |= ( i_width - i_x ) << 2;
 441                             }
 442                             else
 443                             {
 444                                 /* We have a boo boo ! */
 445                                 msg_Err( p_dec, "unknown RLE code "
 446                                          "0x%.4x", i_code );
 447                                 return VLC_EGENERIC;
 448                             }
 449                         }
 450                     }
 451                 }
 452             }
 453
 454             if( ( (i_code >> 2) + i_x + i_y * i_width ) > i_height * i_width )
 455             {
 456                 msg_Err( p_dec, "out of bounds, %i at (%i,%i) is out of %ix%i",
 457                          i_code >> 2, i_x, i_y, i_width, i_height );
 458                 return VLC_EGENERIC;
 459             }
 460
 461             /* Try to find the border color */
 462             if( p_spu_data->pi_alpha[ i_code & 0x3 ] != 0x00 )
 463             {
 464                 i_border = i_code & 0x3;
 465                 stats[i_border] += i_code >> 2;
 466             }
 467
 468             /* Auto crop subtitles (a lot more optimized) */
 469             if( p_spu_data->b_auto_crop )
 470             {
 471                 if( !i_y )
 472                 {
 473                     /* We assume that if the first line is transparent, then
 474                      * it is using the palette index for the
 475                      * (background) transparent color */
 476                     if( (i_code >> 2) == i_width &&
 477                         p_spu_data->pi_alpha[ i_code & 0x3 ] == 0x00 )
 478                     {
 479                         i_transparent_code = i_code;
 480                     }
 481                     else
 482                     {
 483                         p_spu_data->b_auto_crop = VLC_FALSE;
 484                     }
 485                 }
 486
 487                 if( i_code == i_transparent_code )
 488                 {
 489                     if( b_empty_top )
 490                     {
 491                         /* This is a blank top line, we skip it */
 492                       i_skipped_top++;
 493                     }
 494                     else
 495                     {
 496                         /* We can't be sure the current lines will be skipped,
 497                          * so we store the code just in case. */
 498                       *p_dest++ = i_code;
 499                       i_skipped_bottom++;
 500                     }
 501                 }
 502                 else
 503                 {
 504                     /* We got a valid code, store it */
 505                     *p_dest++ = i_code;
 506
 507                     /* Valid code means no blank line */
 508                     b_empty_top = VLC_FALSE;
 509                     i_skipped_bottom = 0;
 510                 }
 511             }
 512             else
 513             {
 514                 *p_dest++ = i_code;
 515             }
 516         }
 517
 518         /* Check that we didn't go too far */
 519         if( i_x > i_width )
 520         {
 521             msg_Err( p_dec, "i_x overflowed, %i > %i", i_x, i_width );
 522             return VLC_EGENERIC;
 523         }
 524
 525         /* Byte-align the stream */
 526         if( *pi_offset & 0x1 )
 527         {
 528             (*pi_offset)++;
 529         }
 530
 531         /* Swap fields */
 532         i_id = ~i_id & 0x1;
 533     }
 534
 535     /* We shouldn't get any padding bytes */
 536     if( i_y < i_height )
 537     {
 538         msg_Err( p_dec, "padding bytes found in RLE sequence" );
 539         msg_Err( p_dec, "send mail to <sam@zoy.org> if you "
 540                         "want to help debugging this" );
 541
 542         /* Skip them just in case */
 543         while( i_y < i_height )
 544         {
 545             *p_dest++ = i_width << 2;
 546             i_y++;
 547         }
 548
 549         return VLC_EGENERIC;
 550     }
 551
 552 #ifdef DEBUG_SPUDEC
 553     msg_Dbg( p_dec, "valid subtitle, size: %ix%i, position: %i,%i",
 554              p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y );
 555 #endif
 556
 557     /* Crop if necessary */
 558     if( i_skipped_top || i_skipped_bottom )
 559     {
 560 #ifdef DEBUG_SPUDEC
 561         int i_y = p_spu->i_y + i_skipped_top;
 562         int i_height = p_spu->i_height - (i_skipped_top + i_skipped_bottom);
 563 #endif
 564         p_spu_data->i_y_top_offset = i_skipped_top;
 565         p_spu_data->i_y_bottom_offset = i_skipped_bottom;
 566 #ifdef DEBUG_SPUDEC
 567         msg_Dbg( p_dec, "cropped to: %ix%i, position: %i,%i",
 568                  p_spu->i_width, i_height, p_spu->i_x, i_y );
 569 #endif
 570     }
 571
 572     /* Handle color if no palette was found */
 573     if( !p_spu_data->b_palette )
 574     {
 575         int i, i_inner = -1, i_shade = -1;
 576
 577         /* Set the border color */
 578         p_spu_data->pi_yuv[i_border][0] = 0x00;
 579         p_spu_data->pi_yuv[i_border][1] = 0x80;
 580         p_spu_data->pi_yuv[i_border][2] = 0x80;
 581         stats[i_border] = 0;
 582
 583         /* Find the inner colors */
 584         for( i = 0 ; i < 4 && i_inner == -1 ; i++ )
 585         {
 586             if( stats[i] )
 587             {
 588                 i_inner = i;
 589             }
 590         }
 591
 592         for(       ; i < 4 && i_shade == -1 ; i++ )
 593         {
 594             if( stats[i] )
 595             {
 596                 if( stats[i] > stats[i_inner] )
 597                 {
 598                     i_shade = i_inner;
 599                     i_inner = i;
 600                 }
 601                 else
 602                 {
 603                     i_shade = i;
 604                 }
 605             }
 606         }
 607
 608         /* Set the inner color */
 609         if( i_inner != -1 )
 610         {
 611             p_spu_data->pi_yuv[i_inner][0] = 0xff;
 612             p_spu_data->pi_yuv[i_inner][1] = 0x80;
 613             p_spu_data->pi_yuv[i_inner][2] = 0x80;
 614         }
 615
 616         /* Set the anti-aliasing color */
 617         if( i_shade != -1 )
 618         {
 619             p_spu_data->pi_yuv[i_shade][0] = 0x80;
 620             p_spu_data->pi_yuv[i_shade][1] = 0x80;
 621             p_spu_data->pi_yuv[i_shade][2] = 0x80;
 622         }
 623
 624 #ifdef DEBUG_SPUDEC
 625         msg_Dbg( p_dec, "using custom palette (border %i, inner %i, shade %i)",
 626                  i_border, i_inner, i_shade );
 627 #endif
 628     }
 629
 630     return VLC_SUCCESS;
 631 }
 632
 633 static void Render( decoder_t *p_dec, subpicture_t *p_spu,
 634                     subpicture_data_t *p_spu_data )
 635 {
 636     uint8_t *p_p;
 637     int i_x, i_y, i_len, i_color, i_pitch;
 638     uint16_t *p_source = (uint16_t *)p_spu_data->p_data;
 639     video_format_t fmt;
 640
 641     /* Create a new subpicture region */
 642     memset( &fmt, 0, sizeof(video_format_t) );
 643     fmt.i_chroma = VLC_FOURCC('Y','U','V','P');
 644     fmt.i_aspect = 0; /* 0 means use aspect ratio of background video */
 645     fmt.i_width = fmt.i_visible_width = p_spu->i_width;
 646     fmt.i_height = fmt.i_visible_height = p_spu->i_height -
 647         p_spu_data->i_y_top_offset - p_spu_data->i_y_bottom_offset;
 648     fmt.i_x_offset = fmt.i_y_offset = 0;
 649     p_spu->p_region = p_spu->pf_create_region( VLC_OBJECT(p_dec), &fmt );
 650     if( !p_spu->p_region )
 651     {
 652         msg_Err( p_dec, "cannot allocate SPU region" );
 653         return;
 654     }
 655
 656     p_spu->p_region->i_x = 0;
 657     p_spu->p_region->i_y = p_spu_data->i_y_top_offset;
 658     p_p = p_spu->p_region->picture.p->p_pixels;
 659     i_pitch = p_spu->p_region->picture.p->i_pitch;
 660
 661     /* Build palette */
 662     fmt.p_palette->i_entries = 4;
 663     for( i_x = 0; i_x < fmt.p_palette->i_entries; i_x++ )
 664     {
 665         fmt.p_palette->palette[i_x][0] = p_spu_data->pi_yuv[i_x][0];
 666         fmt.p_palette->palette[i_x][1] = p_spu_data->pi_yuv[i_x][1];
 667         fmt.p_palette->palette[i_x][2] = p_spu_data->pi_yuv[i_x][2];
 668         fmt.p_palette->palette[i_x][3] =
 669             p_spu_data->pi_alpha[i_x] == 0xf ? 0xff :
 670             p_spu_data->pi_alpha[i_x] << 4;
 671     }
 672
 673     /* Draw until we reach the bottom of the subtitle */
 674     for( i_y = 0; i_y < (int)fmt.i_height * i_pitch; i_y += i_pitch )
 675     {
 676         /* Draw until we reach the end of the line */
 677         for( i_x = 0 ; i_x < (int)fmt.i_width; i_x += i_len )
 678         {
 679             /* Get the RLE part, then draw the line */
 680             i_color = *p_source & 0x3;
 681             i_len = *p_source++ >> 2;
 682             memset( p_p + i_x + i_y, i_color, i_len );
 683         }
 684     }
 685 }