git.sesse.net Git - vlc/blob - plugins/spudec/spu_decoder.c

   1 /*****************************************************************************
   2  * spu_decoder.c : spu decoder thread
   3  *****************************************************************************
   4  * Copyright (C) 2000-2001 VideoLAN
   5  * $Id: spu_decoder.c,v 1.4 2001/12/27 01:49:34 massiot Exp $
   6  *
   7  * Authors: Samuel Hocevar <sam@zoy.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  22  *****************************************************************************/
  23
  24 #define MODULE_NAME spudec
  25 #include "modules_inner.h"
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30 #include "defs.h"
  31
  32 #ifdef HAVE_UNISTD_H
  33 #include <unistd.h>                                              /* getpid() */
  34 #endif
  35
  36 #ifdef WIN32                   /* getpid() for win32 is located in process.h */
  37 #include <process.h>
  38 #endif
  39
  40 #include <stdlib.h>                                      /* malloc(), free() */
  41 #include <string.h>                                    /* memcpy(), memset() */
  42
  43 #include "common.h"
  44 #include "intf_msg.h"
  45 #include "threads.h"
  46 #include "mtime.h"
  47
  48 #include "video.h"
  49 #include "video_output.h"
  50
  51 #include "stream_control.h"
  52 #include "input_ext-dec.h"
  53
  54 #include "spu_decoder.h"
  55
  56 #include "modules.h"
  57 #include "modules_export.h"
  58
  59 /*****************************************************************************
  60  * Local prototypes
  61  *****************************************************************************/
  62 static int  spudec_Probe         ( probedata_t * );
  63 static int  spudec_Run           ( decoder_config_t * );
  64 static int  spudec_Init          ( spudec_thread_t * );
  65 static void spudec_ErrorThread   ( spudec_thread_t * );
  66 static void spudec_EndThread     ( spudec_thread_t * );
  67
  68 static int  SyncPacket           ( spudec_thread_t * );
  69 static void ParsePacket          ( spudec_thread_t * );
  70 static int  ParseControlSequences( spudec_thread_t *, subpicture_t * );
  71 static int  ParseRLE             ( spudec_thread_t *, subpicture_t *, u8 * );
  72
  73 /*****************************************************************************
  74  * Capabilities
  75  *****************************************************************************/
  76 void _M( spudec_getfunctions )( function_list_t * p_function_list )
  77 {
  78     p_function_list->pf_probe = spudec_Probe;
  79     p_function_list->functions.dec.pf_run = spudec_Run;
  80 }
  81
  82 /*****************************************************************************
  83  * Build configuration tree.
  84  *****************************************************************************/
  85 MODULE_CONFIG_START
  86 ADD_WINDOW( "Configuration for SPU decoder module" )
  87     ADD_COMMENT( "Nothing to configure" )
  88 MODULE_CONFIG_STOP
  89
  90 MODULE_INIT_START
  91     p_module->i_capabilities = MODULE_CAPABILITY_DEC;
  92     p_module->psz_longname = "subtitles decoder module";
  93 MODULE_INIT_STOP
  94
  95 MODULE_ACTIVATE_START
  96     _M( spudec_getfunctions )( &p_module->p_functions->dec );
  97 MODULE_ACTIVATE_STOP
  98
  99 MODULE_DEACTIVATE_START
 100 MODULE_DEACTIVATE_STOP
 101
 102 /*****************************************************************************
 103  * spudec_Probe: probe the decoder and return score
 104  *****************************************************************************
 105  * Tries to launch a decoder and return score so that the interface is able
 106  * to chose.
 107  *****************************************************************************/
 108 static int spudec_Probe( probedata_t *p_data )
 109 {
 110     if( p_data->i_type == DVD_SPU_ES )
 111         return( 50 );
 112     else
 113         return( 0 );
 114 }
 115
 116 /*****************************************************************************
 117  * spudec_Run: this function is called just after the thread is created
 118  *****************************************************************************/
 119 static int spudec_Run( decoder_config_t * p_config )
 120 {
 121     spudec_thread_t *     p_spudec;
 122
 123     intf_WarnMsg( 3, "spudec: thread launched. Initializing ..." );
 124
 125     /* Allocate the memory needed to store the thread's structure */
 126     p_spudec = (spudec_thread_t *)malloc( sizeof(spudec_thread_t) );
 127
 128     if ( p_spudec == NULL )
 129     {
 130         intf_ErrMsg( "spudec error: not enough memory "
 131                      "for spudec_CreateThread() to create the new thread" );
 132         return( -1 );
 133     }
 134
 135     /*
 136      * Initialize the thread properties
 137      */
 138     p_spudec->p_config = p_config;
 139
 140     p_spudec->p_fifo = p_config->p_decoder_fifo;
 141
 142     /*
 143      * Initialize thread and free configuration
 144      */
 145     p_spudec->p_fifo->b_error = spudec_Init( p_spudec );
 146
 147     /*
 148      * Main loop - it is not executed if an error occured during
 149      * initialization
 150      */
 151     while( (!p_spudec->p_fifo->b_die) && (!p_spudec->p_fifo->b_error) )
 152     {
 153         if( !SyncPacket( p_spudec ) )
 154         {
 155             ParsePacket( p_spudec );
 156         }
 157     }
 158
 159     /*
 160      * Error loop
 161      */
 162     if( p_spudec->p_fifo->b_error )
 163     {
 164         spudec_ErrorThread( p_spudec );
 165     }
 166
 167     /* End of thread */
 168     spudec_EndThread( p_spudec );
 169
 170     if( p_spudec->p_fifo->b_error )
 171     {
 172         return( -1 );
 173     }
 174
 175     return( 0 );
 176
 177 }
 178
 179 /* following functions are local */
 180
 181 /*****************************************************************************
 182  * spudec_Init: initialize spu decoder thread
 183  *****************************************************************************
 184  * This function is called from RunThread and performs the second step of the
 185  * initialization. It returns 0 on success. Note that the thread's flag are not
 186  * modified inside this function.
 187  *****************************************************************************/
 188 static int spudec_Init( spudec_thread_t *p_spudec )
 189 {
 190     int i_retry = 0;
 191
 192     /* Spawn a video output if there is none */
 193     vlc_mutex_lock( &p_vout_bank->lock );
 194
 195     while( p_vout_bank->i_count == 0 )
 196     {
 197         vlc_mutex_unlock( &p_vout_bank->lock );
 198
 199         if( i_retry++ > 10 )
 200         {
 201             intf_WarnMsg( 1, "spudec: waited too long for vout, aborting" );
 202             free( p_spudec );
 203
 204             return( -1 );
 205         }
 206
 207         msleep( VOUT_OUTMEM_SLEEP );
 208         vlc_mutex_lock( &p_vout_bank->lock );
 209     }
 210
 211     /* Take the first video output FIXME: take the best one */
 212     p_spudec->p_vout = p_vout_bank->pp_vout[ 0 ];
 213     vlc_mutex_unlock( &p_vout_bank->lock );
 214     p_spudec->p_config->pf_init_bit_stream(
 215             &p_spudec->bit_stream,
 216             p_spudec->p_config->p_decoder_fifo, NULL, NULL );
 217
 218     /* Mark thread as running and return */
 219     return( 0 );
 220 }
 221
 222 /*****************************************************************************
 223  * spudec_ErrorThread: spudec_Run() error loop
 224  *****************************************************************************
 225  * This function is called when an error occured during thread main's loop. The
 226  * thread can still receive feed, but must be ready to terminate as soon as
 227  * possible.
 228  *****************************************************************************/
 229 static void spudec_ErrorThread( spudec_thread_t *p_spudec )
 230 {
 231     /* We take the lock, because we are going to read/write the start/end
 232      * indexes of the decoder fifo */
 233     vlc_mutex_lock( &p_spudec->p_fifo->data_lock );
 234
 235     /* Wait until a `die' order is sent */
 236     while( !p_spudec->p_fifo->b_die )
 237     {
 238         /* Trash all received PES packets */
 239         p_spudec->p_fifo->pf_delete_pes(
 240                         p_spudec->p_fifo->p_packets_mgt,
 241                         p_spudec->p_fifo->p_first );
 242
 243         /* Waiting for the input thread to put new PES packets in the fifo */
 244         vlc_cond_wait( &p_spudec->p_fifo->data_wait,
 245                        &p_spudec->p_fifo->data_lock );
 246     }
 247
 248     /* We can release the lock before leaving */
 249     vlc_mutex_unlock( &p_spudec->p_fifo->data_lock );
 250 }
 251
 252 /*****************************************************************************
 253  * spudec_EndThread: thread destruction
 254  *****************************************************************************
 255  * This function is called when the thread ends after a sucessful
 256  * initialization.
 257  *****************************************************************************/
 258 static void spudec_EndThread( spudec_thread_t *p_spudec )
 259 {
 260     free( p_spudec );
 261 }
 262
 263 /*****************************************************************************
 264  * SyncPacket: get in sync with the stream
 265  *****************************************************************************
 266  * This function makes a few sanity checks and returns 0 if it looks like we
 267  * are at the beginning of a subpicture packet.
 268  *****************************************************************************/
 269 static int SyncPacket( spudec_thread_t *p_spudec )
 270 {
 271     /* Re-align the buffer on an 8-bit boundary */
 272     RealignBits( &p_spudec->bit_stream );
 273
 274     /* The total SPU packet size, often bigger than a PS packet */
 275     p_spudec->i_spu_size = GetBits( &p_spudec->bit_stream, 16 );
 276
 277     /* The RLE stuff size (remove 4 because we just read 32 bits) */
 278     p_spudec->i_rle_size = ShowBits( &p_spudec->bit_stream, 16 ) - 4;
 279
 280     /* If the values we got are a bit strange, skip packet */
 281     if( !p_spudec->i_spu_size
 282          || ( p_spudec->i_rle_size >= p_spudec->i_spu_size ) )
 283     {
 284         return( 1 );
 285     }
 286
 287     RemoveBits( &p_spudec->bit_stream, 16 );
 288
 289     return( 0 );
 290 }
 291
 292 /*****************************************************************************
 293  * ParsePacket: parse an SPU packet and send it to the video output
 294  *****************************************************************************
 295  * This function parses the SPU packet and, if valid, sends it to the
 296  * video output.
 297  *****************************************************************************/
 298 static void ParsePacket( spudec_thread_t *p_spudec )
 299 {
 300     subpicture_t * p_spu;
 301     u8           * p_src;
 302     unsigned int   i_offset;
 303
 304     intf_WarnMsg( 3, "spudec: trying to gather a 0x%.2x long subtitle",
 305                   p_spudec->i_spu_size );
 306
 307     /* We cannot display a subpicture with no date */
 308     if( p_spudec->p_fifo->p_first->i_pts == 0 )
 309     {
 310         intf_WarnMsg( 3, "spudec error: subtitle without a date" );
 311         return;
 312     }
 313
 314     /* Allocate the subpicture internal data. */
 315     p_spu = vout_CreateSubPicture( p_spudec->p_vout, DVD_SUBPICTURE,
 316                                    p_spudec->i_rle_size * 4 );
 317     /* Rationale for the "p_spudec->i_rle_size * 4": we are going to
 318      * expand the RLE stuff so that we won't need to read nibbles later
 319      * on. This will speed things up a lot. Plus, we'll only need to do
 320      * this stupid interlacing stuff once. */
 321
 322     if( p_spu == NULL )
 323     {
 324         return;
 325     }
 326
 327     /* Get display time now. If we do it later, we may miss the PTS. */
 328     p_spudec->i_pts = p_spudec->p_fifo->p_first->i_pts;
 329
 330     /* Allocate the temporary buffer we will parse */
 331     p_src = malloc( p_spudec->i_rle_size );
 332
 333     if( p_src == NULL )
 334     {
 335         intf_ErrMsg( "spudec error: could not allocate p_src" );
 336         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 337         return;
 338     }
 339
 340     /* Get RLE data */
 341     for( i_offset = 0;
 342          i_offset + SPU_CHUNK_SIZE < p_spudec->i_rle_size;
 343          i_offset += SPU_CHUNK_SIZE )
 344     {
 345         GetChunk( &p_spudec->bit_stream, p_src + i_offset, SPU_CHUNK_SIZE );
 346
 347         /* Abort subtitle parsing if we were requested to stop */
 348         if( p_spudec->p_fifo->b_die )
 349         {
 350             free( p_src );
 351             vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 352             return;
 353         }
 354     }
 355
 356     GetChunk( &p_spudec->bit_stream, p_src + i_offset,
 357               p_spudec->i_rle_size - i_offset );
 358
 359 #if 0
 360     /* Dump the subtitle info */
 361     intf_WarnHexDump( 5, p_spu->p_data, p_spudec->i_rle_size );
 362 #endif
 363
 364     /* Getting the control part */
 365     if( ParseControlSequences( p_spudec, p_spu ) )
 366     {
 367         /* There was a parse error, delete the subpicture */
 368         free( p_src );
 369         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 370         return;
 371     }
 372
 373     /* At this point, no more GetBit() command is needed, so we have all
 374      * the data we need to tell whether the subtitle is valid. Thus we
 375      * try to display it and we ignore b_die. */
 376
 377     if( ParseRLE( p_spudec, p_spu, p_src ) )
 378     {
 379         /* There was a parse error, delete the subpicture */
 380         free( p_src );
 381         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 382         return;
 383     }
 384
 385     intf_WarnMsg( 3, "spudec: total size: 0x%x, RLE offsets: 0x%x 0x%x",
 386                   p_spudec->i_spu_size,
 387                   p_spu->type.spu.i_offset[0], p_spu->type.spu.i_offset[1] );
 388
 389     /* SPU is finished - we can ask the video output to display it */
 390     vout_DisplaySubPicture( p_spudec->p_vout, p_spu );
 391
 392     /* Clean up */
 393     free( p_src );
 394 }
 395
 396 /*****************************************************************************
 397  * ParseControlSequences: parse all SPU control sequences
 398  *****************************************************************************
 399  * This is the most important part in SPU decoding. We get dates, palette
 400  * information, coordinates, and so on. For more information on the
 401  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 402  *****************************************************************************/
 403 static int ParseControlSequences( spudec_thread_t *p_spudec,
 404                                   subpicture_t * p_spu )
 405 {
 406     /* Our current index in the SPU packet */
 407     int i_index = p_spudec->i_rle_size + 4;
 408
 409     /* The next start-of-control-sequence index and the previous one */
 410     int i_next_seq, i_cur_seq;
 411
 412     /* Command time and date */
 413     u8  i_command;
 414     int i_date;
 415
 416     /* XXX: temporary variables */
 417     boolean_t b_force_display = 0;
 418
 419     /* Initialize the structure */
 420     p_spu->i_start = p_spu->i_stop = 0;
 421     p_spu->b_ephemer = 0;
 422
 423     do
 424     {
 425         /* Get the control sequence date */
 426         i_date = GetBits( &p_spudec->bit_stream, 16 );
 427
 428         /* Next offset */
 429         i_cur_seq = i_index;
 430         i_next_seq = GetBits( &p_spudec->bit_stream, 16 );
 431
 432         /* Skip what we just read */
 433         i_index += 4;
 434
 435         do
 436         {
 437             i_command = GetBits( &p_spudec->bit_stream, 8 );
 438             i_index++;
 439
 440             switch( i_command )
 441             {
 442                 case SPU_CMD_FORCE_DISPLAY:
 443
 444                     /* 00 (force displaying) */
 445                     p_spu->i_start = p_spudec->i_pts + ( i_date * 11000 );
 446                     b_force_display = 1;
 447
 448                     break;
 449
 450                 /* Convert the dates in seconds to PTS values */
 451                 case SPU_CMD_START_DISPLAY:
 452
 453                     /* 01 (start displaying) */
 454                     p_spu->i_start = p_spudec->i_pts + ( i_date * 11000 );
 455
 456                     break;
 457
 458                 case SPU_CMD_STOP_DISPLAY:
 459
 460                     /* 02 (stop displaying) */
 461                     p_spu->i_stop = p_spudec->i_pts + ( i_date * 11000 );
 462
 463                     break;
 464
 465                 case SPU_CMD_SET_PALETTE:
 466
 467                     /* 03xxxx (palette) - trashed */
 468                     RemoveBits( &p_spudec->bit_stream, 16 );
 469                     i_index += 2;
 470
 471                     break;
 472
 473                 case SPU_CMD_SET_ALPHACHANNEL:
 474
 475                     /* 04xxxx (alpha channel) - trashed */
 476                     RemoveBits( &p_spudec->bit_stream, 16 );
 477                     i_index += 2;
 478
 479                     break;
 480
 481                 case SPU_CMD_SET_COORDINATES:
 482
 483                     /* 05xxxyyyxxxyyy (coordinates) */
 484                     p_spu->i_x = GetBits( &p_spudec->bit_stream, 12 );
 485                     p_spu->i_width = GetBits( &p_spudec->bit_stream, 12 )
 486                                       - p_spu->i_x + 1;
 487
 488                     p_spu->i_y = GetBits( &p_spudec->bit_stream, 12 );
 489                     p_spu->i_height = GetBits( &p_spudec->bit_stream, 12 )
 490                                        - p_spu->i_y + 1;
 491
 492                     i_index += 6;
 493
 494                     break;
 495
 496                 case SPU_CMD_SET_OFFSETS:
 497
 498                     /* 06xxxxyyyy (byte offsets) */
 499                     p_spu->type.spu.i_offset[0] =
 500                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 501
 502                     p_spu->type.spu.i_offset[1] =
 503                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 504
 505                     i_index += 4;
 506
 507                     break;
 508
 509                 case SPU_CMD_END:
 510
 511                     /* ff (end) */
 512                     break;
 513
 514                 default:
 515
 516                     /* xx (unknown command) */
 517                     intf_ErrMsg( "spudec error: unknown command 0x%.2x",
 518                                  i_command );
 519                     return( 1 );
 520             }
 521
 522             /* We need to check for quit commands here */
 523             if( p_spudec->p_fifo->b_die )
 524             {
 525                 return( 1 );
 526             }
 527
 528         } while( i_command != SPU_CMD_END );
 529
 530     } while( i_index == i_next_seq );
 531
 532     /* Check that the next sequence index matches the current one */
 533     if( i_next_seq != i_cur_seq )
 534     {
 535         intf_ErrMsg( "spudec error: index mismatch (0x%.4x != 0x%.4x)",
 536                      i_next_seq, i_cur_seq );
 537         return( 1 );
 538     }
 539
 540     if( i_index > p_spudec->i_spu_size )
 541     {
 542         intf_ErrMsg( "spudec error: uh-oh, we went too far (0x%.4x > 0x%.4x)",
 543                      i_index, p_spudec->i_spu_size );
 544         return( 1 );
 545     }
 546
 547     if( !p_spu->i_start )
 548     {
 549         intf_ErrMsg( "spudec error: no `start display' command" );
 550     }
 551
 552     if( !p_spu->i_stop )
 553     {
 554         /* This subtitle will live for 5 seconds or until the next subtitle */
 555         p_spu->i_stop = p_spu->i_start + 500 * 11000;
 556         p_spu->b_ephemer = 1;
 557     }
 558
 559     /* Get rid of padding bytes */
 560     switch( p_spudec->i_spu_size - i_index )
 561     {
 562         /* Zero or one padding byte, quite usual */
 563         case 1:
 564             RemoveBits( &p_spudec->bit_stream, 8 );
 565             i_index++;
 566         case 0:
 567             break;
 568
 569         /* More than one padding byte - this is very strange, but
 570          * we can deal with it */
 571         default:
 572             intf_WarnMsg( 2, "spudec warning: %i padding bytes, we usually "
 573                              "get 0 or 1 of them",
 574                           p_spudec->i_spu_size - i_index );
 575
 576             while( i_index < p_spudec->i_spu_size )
 577             {
 578                 RemoveBits( &p_spudec->bit_stream, 8 );
 579                 i_index++;
 580             }
 581
 582             break;
 583     }
 584
 585     if( b_force_display )
 586     {
 587         intf_ErrMsg( "spudec: \"force display\" command" );
 588         intf_ErrMsg( "spudec: send mail to <sam@zoy.org> if you "
 589                      "want to help debugging this" );
 590     }
 591
 592     /* Successfully parsed ! */
 593     return( 0 );
 594 }
 595
 596 /*****************************************************************************
 597  * ParseRLE: parse the RLE part of the subtitle
 598  *****************************************************************************
 599  * This part parses the subtitle graphical data and stores it in a more
 600  * convenient structure for later decoding. For more information on the
 601  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 602  *****************************************************************************/
 603 static int ParseRLE( spudec_thread_t *p_spudec,
 604                      subpicture_t * p_spu, u8 * p_src )
 605 {
 606     unsigned int i_code;
 607
 608     unsigned int i_width = p_spu->i_width;
 609     unsigned int i_height = p_spu->i_height;
 610     unsigned int i_x, i_y;
 611
 612     u16 *p_dest = (u16 *)p_spu->p_data;
 613
 614     /* The subtitles are interlaced, we need two offsets */
 615     unsigned int  i_id = 0;                   /* Start on the even SPU layer */
 616     unsigned int  pi_table[ 2 ];
 617     unsigned int *pi_offset;
 618
 619     boolean_t b_empty_top = 1,
 620               b_empty_bottom = 0;
 621     unsigned int i_skipped_top = 0,
 622                  i_skipped_bottom = 0;
 623
 624     pi_table[ 0 ] = p_spu->type.spu.i_offset[ 0 ] << 1;
 625     pi_table[ 1 ] = p_spu->type.spu.i_offset[ 1 ] << 1;
 626
 627     for( i_y = 0 ; i_y < i_height ; i_y++ )
 628     {
 629         pi_offset = pi_table + i_id;
 630
 631         for( i_x = 0 ; i_x < i_width ; i_x += i_code >> 2 )
 632         {
 633             i_code = AddNibble( 0, p_src, pi_offset );
 634
 635             if( i_code < 0x04 )
 636             {
 637                 i_code = AddNibble( i_code, p_src, pi_offset );
 638
 639                 if( i_code < 0x10 )
 640                 {
 641                     i_code = AddNibble( i_code, p_src, pi_offset );
 642
 643                     if( i_code < 0x040 )
 644                     {
 645                         i_code = AddNibble( i_code, p_src, pi_offset );
 646
 647                         if( i_code < 0x0100 )
 648                         {
 649                             /* If the 14 first bits are set to 0, then it's a
 650                              * new line. We emulate it. */
 651                             if( i_code < 0x0004 )
 652                             {
 653                                 i_code |= ( i_width - i_x ) << 2;
 654                             }
 655                             else
 656                             {
 657                                 /* We have a boo boo ! */
 658                                 intf_ErrMsg( "spudec error: unknown RLE code "
 659                                              "0x%.4x", i_code );
 660                                 return( 1 );
 661                             }
 662                         }
 663                     }
 664                 }
 665             }
 666
 667             if( ( (i_code >> 2) + i_x + i_y * i_width ) > i_height * i_width )
 668             {
 669                 intf_ErrMsg( "spudec error: out of bounds, %i at (%i,%i) is "
 670                              "out of %ix%i",
 671                              i_code >> 2, i_x, i_y, i_width, i_height );
 672                 return( 1 );
 673             }
 674
 675             if( i_code == (i_width << 2) ) /* FIXME: we assume 0 is transp */
 676             {
 677                 if( b_empty_top )
 678                 {
 679                     /* This is a blank top line, we skip it */
 680                     i_skipped_top++;
 681                 }
 682                 else
 683                 {
 684                     /* We can't be sure the current lines will be skipped,
 685                      * so we store the code just in case. */
 686                     *p_dest++ = i_code;
 687
 688                     b_empty_bottom = 1;
 689                     i_skipped_bottom++;
 690                 }
 691             }
 692             else
 693             {
 694                 /* We got a valid code, store it */
 695                 *p_dest++ = i_code;
 696
 697                 /* Valid code means no blank line */
 698                 b_empty_top = 0;
 699                 b_empty_bottom = 0;
 700                 i_skipped_bottom = 0;
 701             }
 702         }
 703
 704         /* Check that we didn't go too far */
 705         if( i_x > i_width )
 706         {
 707             intf_ErrMsg( "spudec error: i_x overflowed, %i > %i",
 708                          i_x, i_width );
 709             return( 1 );
 710         }
 711
 712         /* Byte-align the stream */
 713         if( *pi_offset & 0x1 )
 714         {
 715             (*pi_offset)++;
 716         }
 717
 718         /* Swap fields */
 719         i_id = ~i_id & 0x1;
 720     }
 721
 722     /* We shouldn't get any padding bytes */
 723     if( i_y < i_height )
 724     {
 725         intf_ErrMsg( "spudec: padding bytes found in RLE sequence" );
 726         intf_ErrMsg( "spudec: send mail to <sam@zoy.org> if you "
 727                      "want to help debugging this" );
 728
 729         /* Skip them just in case */
 730         while( i_y < i_height )
 731         {
 732             *p_dest++ = i_width << 2;
 733             i_y++;
 734         }
 735
 736         return( 1 );
 737     }
 738
 739     intf_WarnMsg( 3, "spudec: valid subtitle, size: %ix%i, position: %i,%i",
 740                   p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y );
 741
 742     /* Crop if necessary */
 743     if( i_skipped_top || i_skipped_bottom )
 744     {
 745         p_spu->i_y += i_skipped_top;
 746         p_spu->i_height -= i_skipped_top + i_skipped_bottom;
 747
 748         intf_WarnMsg( 3, "spudec: cropped to: %ix%i, position: %i,%i",
 749                       p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y );
 750     }
 751
 752     return( 0 );
 753 }
 754