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     /* Rationale for the "p_spudec->i_rle_size * 4": we are going to
  75      * expand the RLE stuff so that we won't need to read nibbles later
  76      * on. This will speed things up a lot. Plus, we'll only need to do
  77      * this stupid interlacing stuff once. */
  78     p_spu_data = malloc( sizeof(subpicture_data_t) + 4 * p_sys->i_rle_size );
  79     p_spu_data->p_data = (uint8_t *)p_spu_data + sizeof(subpicture_data_t);
  80     p_spu_data->b_palette = VLC_FALSE;
  81     p_spu_data->b_auto_crop = VLC_FALSE;
  82     p_spu_data->i_y_top_offset = 0;
  83     p_spu_data->i_y_bottom_offset = 0;
  84
  85     p_spu_data->pi_alpha[0] = 0x00;
  86     p_spu_data->pi_alpha[1] = 0x0f;
  87     p_spu_data->pi_alpha[2] = 0x0f;
  88     p_spu_data->pi_alpha[3] = 0x0f;
  89
  90     /* Get display time now. If we do it later, we may miss the PTS. */
  91     p_spu_data->i_pts = p_sys->i_pts;
  92
  93     p_spu->i_original_picture_width =
  94         p_dec->fmt_in.subs.spu.i_original_frame_width;
  95     p_spu->i_original_picture_height =
  96         p_dec->fmt_in.subs.spu.i_original_frame_height;
  97
  98     /* Getting the control part */
  99     if( ParseControlSeq( p_dec, p_spu, p_spu_data ) )
 100     {
 101         /* There was a parse error, delete the subpicture */
 102         p_dec->pf_spu_buffer_del( p_dec, p_spu );
 103         return NULL;
 104     }
 105
 106     /* We try to display it */
 107     if( ParseRLE( p_dec, p_spu, p_spu_data ) )
 108     {
 109         /* There was a parse error, delete the subpicture */
 110         p_dec->pf_spu_buffer_del( p_dec, p_spu );
 111         return NULL;
 112     }
 113
 114     msg_Dbg( p_dec, "total size: 0x%x, RLE offsets: 0x%x 0x%x",
 115              p_sys->i_spu_size,
 116              p_spu_data->pi_offset[0], p_spu_data->pi_offset[1] );
 117
 118     Render( p_dec, p_spu, p_spu_data );
 119     free( p_spu_data );
 120
 121     return p_spu;
 122 }
 123
 124 /*****************************************************************************
 125  * ParseControlSeq: parse all SPU control sequences
 126  *****************************************************************************
 127  * This is the most important part in SPU decoding. We get dates, palette
 128  * information, coordinates, and so on. For more information on the
 129  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 130  *****************************************************************************/
 131 static int ParseControlSeq( decoder_t *p_dec, subpicture_t *p_spu,
 132                             subpicture_data_t *p_spu_data )
 133 {
 134     decoder_sys_t *p_sys = p_dec->p_sys;
 135
 136     /* Our current index in the SPU packet */
 137     unsigned int i_index = p_sys->i_rle_size + 4;
 138
 139     /* The next start-of-control-sequence index and the previous one */
 140     unsigned int i_next_seq = 0, i_cur_seq = 0;
 141
 142     /* Command and date */
 143     uint8_t i_command = SPU_CMD_END;
 144     mtime_t date = 0;
 145
 146     unsigned int i, pi_alpha[4];
 147
 148     /* Initialize the structure */
 149     p_spu->i_start = p_spu->i_stop = 0;
 150     p_spu->b_ephemer = VLC_FALSE;
 151
 152     for( i_index = 4 + p_sys->i_rle_size; i_index < p_sys->i_spu_size ; )
 153     {
 154         /* If we just read a command sequence, read the next one;
 155          * otherwise, go on with the commands of the current sequence. */
 156         if( i_command == SPU_CMD_END )
 157         {
 158             if( i_index + 4 > p_sys->i_spu_size )
 159             {
 160                 msg_Err( p_dec, "overflow in SPU command sequence" );
 161                 return VLC_EGENERIC;
 162             }
 163
 164             /* Get the control sequence date */
 165             date = (mtime_t)GetWBE( &p_sys->buffer[i_index] ) * 11000;
 166             /* FIXME How to access i_rate
 167                     * p_spudec->bit_stream.p_pes->i_rate / DEFAULT_RATE;
 168             */
 169
 170             /* Next offset */
 171             i_cur_seq = i_index;
 172             i_next_seq = GetWBE( &p_sys->buffer[i_index+2] );
 173
 174             if( i_next_seq > p_sys->i_spu_size )
 175             {
 176                 msg_Err( p_dec, "overflow in SPU next command sequence" );
 177                 return VLC_EGENERIC;
 178             }
 179
 180             /* Skip what we just read */
 181             i_index += 4;
 182         }
 183
 184         i_command = p_sys->buffer[i_index];
 185
 186         switch( i_command )
 187         {
 188         case SPU_CMD_FORCE_DISPLAY: /* 00 (force displaying) */
 189             p_spu->i_start = p_spu_data->i_pts + date;
 190             p_spu->b_ephemer = VLC_TRUE;
 191             i_index += 1;
 192             break;
 193
 194         /* Convert the dates in seconds to PTS values */
 195         case SPU_CMD_START_DISPLAY: /* 01 (start displaying) */
 196             p_spu->i_start = p_spu_data->i_pts + date;
 197             i_index += 1;
 198             break;
 199
 200         case SPU_CMD_STOP_DISPLAY: /* 02 (stop displaying) */
 201             p_spu->i_stop = p_spu_data->i_pts + date;
 202             i_index += 1;
 203             break;
 204
 205         case SPU_CMD_SET_PALETTE:
 206
 207             /* 03xxxx (palette) */
 208             if( i_index + 3 > p_sys->i_spu_size )
 209             {
 210                 msg_Err( p_dec, "overflow in SPU command" );
 211                 return VLC_EGENERIC;
 212             }
 213
 214             if( p_dec->fmt_in.subs.spu.palette[0] == 0xBeeF )
 215             {
 216                 unsigned int idx[4];
 217
 218                 p_spu_data->b_palette = VLC_TRUE;
 219
 220                 idx[0] = (p_sys->buffer[i_index+1]>>4)&0x0f;
 221                 idx[1] = (p_sys->buffer[i_index+1])&0x0f;
 222                 idx[2] = (p_sys->buffer[i_index+2]>>4)&0x0f;
 223                 idx[3] = (p_sys->buffer[i_index+2])&0x0f;
 224
 225                 for( i = 0; i < 4 ; i++ )
 226                 {
 227                     uint32_t i_color = p_dec->fmt_in.subs.spu.palette[1+idx[i]];
 228
 229                     /* FIXME: this job should be done sooner */
 230                     p_spu_data->pi_yuv[3-i][0] = (i_color>>16) & 0xff;
 231                     p_spu_data->pi_yuv[3-i][1] = (i_color>>0) & 0xff;
 232                     p_spu_data->pi_yuv[3-i][2] = (i_color>>8) & 0xff;
 233                 }
 234             }
 235
 236             i_index += 3;
 237             break;
 238
 239         case SPU_CMD_SET_ALPHACHANNEL: /* 04xxxx (alpha channel) */
 240             if( i_index + 3 > p_sys->i_spu_size )
 241             {
 242                 msg_Err( p_dec, "overflow in SPU command" );
 243                 return VLC_EGENERIC;
 244             }
 245
 246             pi_alpha[3] = (p_sys->buffer[i_index+1]>>4)&0x0f;
 247             pi_alpha[2] = (p_sys->buffer[i_index+1])&0x0f;
 248             pi_alpha[1] = (p_sys->buffer[i_index+2]>>4)&0x0f;
 249             pi_alpha[0] = (p_sys->buffer[i_index+2])&0x0f;
 250
 251             /* Ignore blank alpha palette. Sometimes spurious blank
 252              * alpha palettes are present - dunno why. */
 253             if( pi_alpha[0] | pi_alpha[1] | pi_alpha[2] | pi_alpha[3] )
 254             {
 255                 p_spu_data->pi_alpha[0] = pi_alpha[0];
 256                 p_spu_data->pi_alpha[1] = pi_alpha[1];
 257                 p_spu_data->pi_alpha[2] = pi_alpha[2];
 258                 p_spu_data->pi_alpha[3] = pi_alpha[3];
 259             }
 260             else
 261             {
 262                 msg_Warn( p_dec, "ignoring blank alpha palette" );
 263             }
 264
 265             i_index += 3;
 266             break;
 267
 268         case SPU_CMD_SET_COORDINATES: /* 05xxxyyyxxxyyy (coordinates) */
 269             if( i_index + 7 > p_sys->i_spu_size )
 270             {
 271                 msg_Err( p_dec, "overflow in SPU command" );
 272                 return VLC_EGENERIC;
 273             }
 274
 275             p_spu->i_x = (p_sys->buffer[i_index+1]<<4)|
 276                          ((p_sys->buffer[i_index+2]>>4)&0x0f);
 277             p_spu->i_width = (((p_sys->buffer[i_index+2]&0x0f)<<8)|
 278                               p_sys->buffer[i_index+3]) - p_spu->i_x + 1;
 279
 280             p_spu->i_y = (p_sys->buffer[i_index+4]<<4)|
 281                          ((p_sys->buffer[i_index+5]>>4)&0x0f);
 282             p_spu->i_height = (((p_sys->buffer[i_index+5]&0x0f)<<8)|
 283                               p_sys->buffer[i_index+6]) - p_spu->i_y + 1;
 284
 285             /* Auto crop fullscreen subtitles */
 286             if( p_spu->i_height > 250 )
 287                 p_spu_data->b_auto_crop = VLC_TRUE;
 288
 289             i_index += 7;
 290             break;
 291
 292         case SPU_CMD_SET_OFFSETS: /* 06xxxxyyyy (byte offsets) */
 293             if( i_index + 5 > p_sys->i_spu_size )
 294             {
 295                 msg_Err( p_dec, "overflow in SPU command" );
 296                 return VLC_EGENERIC;
 297             }
 298
 299             p_spu_data->pi_offset[0] = GetWBE(&p_sys->buffer[i_index+1]) - 4;
 300             p_spu_data->pi_offset[1] = GetWBE(&p_sys->buffer[i_index+3]) - 4;
 301             i_index += 5;
 302             break;
 303
 304         case SPU_CMD_END: /* ff (end) */
 305             i_index += 1;
 306             break;
 307
 308         default: /* xx (unknown command) */
 309             msg_Warn( p_dec, "unknown SPU command 0x%.2x", i_command );
 310             if( i_index + 1 < i_next_seq )
 311             {
 312                  /* There is at least one other command sequence */
 313                  if( p_sys->buffer[i_next_seq - 1] == SPU_CMD_END )
 314                  {
 315                      /* This is consistent. Skip to that command sequence. */
 316                      i_index = i_next_seq;
 317                  }
 318                  else
 319                  {
 320                      /* There were other commands. */
 321                      msg_Warn( p_dec, "cannot recover, dropping subtitle" );
 322                      return VLC_EGENERIC;
 323                  }
 324             }
 325             else
 326             {
 327                 /* We were in the last command sequence. Stop parsing by
 328                  * pretending we met an SPU_CMD_END command. */
 329                 i_command = SPU_CMD_END;
 330                 i_index++;
 331             }
 332         }
 333
 334         /* We need to check for quit commands here */
 335         if( p_dec->b_die )
 336         {
 337             return VLC_EGENERIC;
 338         }
 339
 340         if( i_command == SPU_CMD_END && i_index != i_next_seq )
 341         {
 342             break;
 343         }
 344     }
 345
 346     /* Check that the next sequence index matches the current one */
 347     if( i_next_seq != i_cur_seq )
 348     {
 349         msg_Err( p_dec, "index mismatch (0x%.4x != 0x%.4x)",
 350                  i_next_seq, i_cur_seq );
 351         return VLC_EGENERIC;
 352     }
 353
 354     if( i_index > p_sys->i_spu_size )
 355     {
 356         msg_Err( p_dec, "uh-oh, we went too far (0x%.4x > 0x%.4x)",
 357                  i_index, p_sys->i_spu_size );
 358         return VLC_EGENERIC;
 359     }
 360
 361     if( !p_spu->i_start )
 362     {
 363         msg_Err( p_dec, "no `start display' command" );
 364     }
 365
 366     if( p_spu->i_stop <= p_spu->i_start && !p_spu->b_ephemer )
 367     {
 368         /* This subtitle will live for 5 seconds or until the next subtitle */
 369         p_spu->i_stop = p_spu->i_start + (mtime_t)500 * 11000;
 370         p_spu->b_ephemer = VLC_TRUE;
 371     }
 372
 373     /* Get rid of padding bytes */
 374     if( p_sys->i_spu_size > i_index + 1 )
 375     {
 376         /* Zero or one padding byte are quite usual
 377          * More than one padding byte - this is very strange, but
 378          * we can ignore them. */
 379         msg_Warn( p_dec, "%i padding bytes, we usually get 0 or 1 of them",
 380                   p_sys->i_spu_size - i_index );
 381     }
 382
 383     /* Successfully parsed ! */
 384     return VLC_SUCCESS;
 385 }
 386
 387 /*****************************************************************************
 388  * ParseRLE: parse the RLE part of the subtitle
 389  *****************************************************************************
 390  * This part parses the subtitle graphical data and stores it in a more
 391  * convenient structure for later decoding. For more information on the
 392  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 393  *****************************************************************************/
 394 static int ParseRLE( decoder_t *p_dec, subpicture_t * p_spu,
 395                      subpicture_data_t *p_spu_data )
 396 {
 397     decoder_sys_t *p_sys = p_dec->p_sys;
 398     uint8_t       *p_src = &p_sys->buffer[4];
 399
 400     unsigned int i_code;
 401
 402     unsigned int i_width = p_spu->i_width;
 403     unsigned int i_height = p_spu->i_height;
 404     unsigned int i_x, i_y;
 405
 406     uint16_t *p_dest = (uint16_t *)p_spu_data->p_data;
 407
 408     /* The subtitles are interlaced, we need two offsets */
 409     unsigned int  i_id = 0;                   /* Start on the even SPU layer */
 410     unsigned int  pi_table[ 2 ];
 411     unsigned int *pi_offset;
 412
 413     /* Cropping */
 414     vlc_bool_t b_empty_top = VLC_TRUE;
 415     unsigned int i_skipped_top = 0, i_skipped_bottom = 0;
 416     unsigned int i_transparent_code = 0;
 417
 418     /* Colormap statistics */
 419     int i_border = -1;
 420     int stats[4]; stats[0] = stats[1] = stats[2] = stats[3] = 0;
 421
 422     pi_table[ 0 ] = p_spu_data->pi_offset[ 0 ] << 1;
 423     pi_table[ 1 ] = p_spu_data->pi_offset[ 1 ] << 1;
 424
 425     for( i_y = 0 ; i_y < i_height ; i_y++ )
 426     {
 427         pi_offset = pi_table + i_id;
 428
 429         for( i_x = 0 ; i_x < i_width ; i_x += i_code >> 2 )
 430         {
 431             i_code = AddNibble( 0, p_src, pi_offset );
 432
 433             if( i_code < 0x04 )
 434             {
 435                 i_code = AddNibble( i_code, p_src, pi_offset );
 436
 437                 if( i_code < 0x10 )
 438                 {
 439                     i_code = AddNibble( i_code, p_src, pi_offset );
 440
 441                     if( i_code < 0x040 )
 442                     {
 443                         i_code = AddNibble( i_code, p_src, pi_offset );
 444
 445                         if( i_code < 0x0100 )
 446                         {
 447                             /* If the 14 first bits are set to 0, then it's a
 448                              * new line. We emulate it. */
 449                             if( i_code < 0x0004 )
 450                             {
 451                                 i_code |= ( i_width - i_x ) << 2;
 452                             }
 453                             else
 454                             {
 455                                 /* We have a boo boo ! */
 456                                 msg_Err( p_dec, "unknown RLE code "
 457                                          "0x%.4x", i_code );
 458                                 return VLC_EGENERIC;
 459                             }
 460                         }
 461                     }
 462                 }
 463             }
 464
 465             if( ( (i_code >> 2) + i_x + i_y * i_width ) > i_height * i_width )
 466             {
 467                 msg_Err( p_dec, "out of bounds, %i at (%i,%i) is out of %ix%i",
 468                          i_code >> 2, i_x, i_y, i_width, i_height );
 469                 return VLC_EGENERIC;
 470             }
 471
 472             /* Try to find the border color */
 473             if( p_spu_data->pi_alpha[ i_code & 0x3 ] != 0x00 )
 474             {
 475                 i_border = i_code & 0x3;
 476                 stats[i_border] += i_code >> 2;
 477             }
 478
 479             /* Auto crop subtitles (a lot more optimized) */
 480             if( p_spu_data->b_auto_crop )
 481             {
 482                 if( !i_y )
 483                 {
 484                     /* We assume that if the first line is transparent, then
 485                      * it is using the palette index for the
 486                      * (background) transparent color */
 487                     if( (i_code >> 2) == i_width &&
 488                         p_spu_data->pi_alpha[ i_code & 0x3 ] == 0x00 )
 489                     {
 490                         i_transparent_code = i_code;
 491                     }
 492                     else
 493                     {
 494                         p_spu_data->b_auto_crop = VLC_FALSE;
 495                     }
 496                 }
 497
 498                 if( i_code == i_transparent_code )
 499                 {
 500                     if( b_empty_top )
 501                     {
 502                         /* This is a blank top line, we skip it */
 503                       i_skipped_top++;
 504                     }
 505                     else
 506                     {
 507                         /* We can't be sure the current lines will be skipped,
 508                          * so we store the code just in case. */
 509                       *p_dest++ = i_code;
 510                       i_skipped_bottom++;
 511                     }
 512                 }
 513                 else
 514                 {
 515                     /* We got a valid code, store it */
 516                     *p_dest++ = i_code;
 517
 518                     /* Valid code means no blank line */
 519                     b_empty_top = VLC_FALSE;
 520                     i_skipped_bottom = 0;
 521                 }
 522             }
 523             else
 524             {
 525                 *p_dest++ = i_code;
 526             }
 527         }
 528
 529         /* Check that we didn't go too far */
 530         if( i_x > i_width )
 531         {
 532             msg_Err( p_dec, "i_x overflowed, %i > %i", i_x, i_width );
 533             return VLC_EGENERIC;
 534         }
 535
 536         /* Byte-align the stream */
 537         if( *pi_offset & 0x1 )
 538         {
 539             (*pi_offset)++;
 540         }
 541
 542         /* Swap fields */
 543         i_id = ~i_id & 0x1;
 544     }
 545
 546     /* We shouldn't get any padding bytes */
 547     if( i_y < i_height )
 548     {
 549         msg_Err( p_dec, "padding bytes found in RLE sequence" );
 550         msg_Err( p_dec, "send mail to <sam@zoy.org> if you "
 551                         "want to help debugging this" );
 552
 553         /* Skip them just in case */
 554         while( i_y < i_height )
 555         {
 556             *p_dest++ = i_width << 2;
 557             i_y++;
 558         }
 559
 560         return VLC_EGENERIC;
 561     }
 562
 563     msg_Dbg( p_dec, "valid subtitle, size: %ix%i, position: %i,%i",
 564              p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y );
 565
 566     /* Crop if necessary */
 567     if( i_skipped_top || i_skipped_bottom )
 568     {
 569         int i_y = p_spu->i_y + i_skipped_top;
 570         int i_height = p_spu->i_height - (i_skipped_top + i_skipped_bottom);
 571
 572         p_spu_data->i_y_top_offset = i_skipped_top;
 573         p_spu_data->i_y_bottom_offset = i_skipped_bottom;
 574         msg_Dbg( p_dec, "cropped to: %ix%i, position: %i,%i",
 575                  p_spu->i_width, i_height, p_spu->i_x, i_y );
 576     }
 577
 578     /* Handle color if no palette was found */
 579     if( !p_spu_data->b_palette )
 580     {
 581         int i, i_inner = -1, i_shade = -1;
 582
 583         /* Set the border color */
 584         p_spu_data->pi_yuv[i_border][0] = 0x00;
 585         p_spu_data->pi_yuv[i_border][1] = 0x80;
 586         p_spu_data->pi_yuv[i_border][2] = 0x80;
 587         stats[i_border] = 0;
 588
 589         /* Find the inner colors */
 590         for( i = 0 ; i < 4 && i_inner == -1 ; i++ )
 591         {
 592             if( stats[i] )
 593             {
 594                 i_inner = i;
 595             }
 596         }
 597
 598         for(       ; i < 4 && i_shade == -1 ; i++ )
 599         {
 600             if( stats[i] )
 601             {
 602                 if( stats[i] > stats[i_inner] )
 603                 {
 604                     i_shade = i_inner;
 605                     i_inner = i;
 606                 }
 607                 else
 608                 {
 609                     i_shade = i;
 610                 }
 611             }
 612         }
 613
 614         /* Set the inner color */
 615         if( i_inner != -1 )
 616         {
 617             p_spu_data->pi_yuv[i_inner][0] = 0xff;
 618             p_spu_data->pi_yuv[i_inner][1] = 0x80;
 619             p_spu_data->pi_yuv[i_inner][2] = 0x80;
 620         }
 621
 622         /* Set the anti-aliasing color */
 623         if( i_shade != -1 )
 624         {
 625             p_spu_data->pi_yuv[i_shade][0] = 0x80;
 626             p_spu_data->pi_yuv[i_shade][1] = 0x80;
 627             p_spu_data->pi_yuv[i_shade][2] = 0x80;
 628         }
 629
 630         msg_Dbg( p_dec, "using custom palette (border %i, inner %i, shade %i)",
 631                  i_border, i_inner, i_shade );
 632     }
 633
 634     return VLC_SUCCESS;
 635 }
 636
 637 static void Render( decoder_t *p_dec, subpicture_t *p_spu,
 638                     subpicture_data_t *p_spu_data )
 639 {
 640     uint8_t *p_p;
 641     int i_x, i_y, i_len, i_color, i_pitch;
 642     uint16_t *p_source = (uint16_t *)p_spu_data->p_data;
 643     video_format_t fmt;
 644
 645     /* Create a new subpicture region */
 646     memset( &fmt, 0, sizeof(video_format_t) );
 647     fmt.i_chroma = VLC_FOURCC('Y','U','V','P');
 648     fmt.i_aspect = 0; /* 0 means use aspect ratio of background video */
 649     fmt.i_width = fmt.i_visible_width = p_spu->i_width;
 650     fmt.i_height = fmt.i_visible_height = p_spu->i_height -
 651         p_spu_data->i_y_top_offset - p_spu_data->i_y_bottom_offset;
 652     fmt.i_x_offset = fmt.i_y_offset = 0;
 653     p_spu->p_region = p_spu->pf_create_region( VLC_OBJECT(p_dec), &fmt );
 654     if( !p_spu->p_region )
 655     {
 656         msg_Err( p_dec, "cannot allocate SPU region" );
 657         return;
 658     }
 659
 660     p_spu->p_region->i_x = 0;
 661     p_spu->p_region->i_y = p_spu_data->i_y_top_offset;
 662     p_p = p_spu->p_region->picture.p->p_pixels;
 663     i_pitch = p_spu->p_region->picture.p->i_pitch;
 664
 665     /* Build palette */
 666     fmt.p_palette->i_entries = 4;
 667     for( i_x = 0; i_x < fmt.p_palette->i_entries; i_x++ )
 668     {
 669         fmt.p_palette->palette[i_x][0] = p_spu_data->pi_yuv[i_x][0];
 670         fmt.p_palette->palette[i_x][1] = p_spu_data->pi_yuv[i_x][1];
 671         fmt.p_palette->palette[i_x][2] = p_spu_data->pi_yuv[i_x][2];
 672         fmt.p_palette->palette[i_x][3] =
 673             p_spu_data->pi_alpha[i_x] == 0xf ? 0xff :
 674             p_spu_data->pi_alpha[i_x] << 4;
 675     }
 676
 677     /* Draw until we reach the bottom of the subtitle */
 678     for( i_y = 0; i_y < (int)fmt.i_height * i_pitch; i_y += i_pitch )
 679     {
 680         /* Draw until we reach the end of the line */
 681         for( i_x = 0 ; i_x < (int)fmt.i_width; i_x += i_len )
 682         {
 683             /* Get the RLE part, then draw the line */
 684             i_color = *p_source & 0x3;
 685             i_len = *p_source++ >> 2;
 686             memset( p_p + i_x + i_y, i_color, i_len );
 687         }
 688     }
 689 }