git.sesse.net Git - vlc/blob - src/spu_decoder/spu_decoder.c

   1 /*****************************************************************************
   2  * spu_decoder.c : spu decoder thread
   3  *****************************************************************************
   4  * Copyright (C) 2000 VideoLAN
   5  * $Id: spu_decoder.c,v 1.49 2001/09/26 12:32:25 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 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27 #include "defs.h"
  28
  29 #ifdef HAVE_UNISTD_H
  30 #include <unistd.h>                                              /* getpid() */
  31 #endif
  32
  33 #ifdef WIN32                   /* getpid() for win32 is located in process.h */
  34 #include <process.h>
  35 #endif
  36
  37 #include <stdlib.h>                                      /* malloc(), free() */
  38 #include <string.h>                                    /* memcpy(), memset() */
  39
  40 #include "config.h"
  41 #include "common.h"
  42 #include "threads.h"
  43 #include "mtime.h"
  44
  45 #include "intf_msg.h"
  46
  47 #include "stream_control.h"
  48 #include "input_ext-dec.h"
  49
  50 #include "video.h"
  51 #include "video_output.h"
  52
  53 #include "spu_decoder.h"
  54
  55 /*****************************************************************************
  56  * Local prototypes
  57  *****************************************************************************/
  58 static int  InitThread  ( spudec_thread_t * );
  59 static void RunThread   ( spudec_thread_t * );
  60 static void ErrorThread ( spudec_thread_t * );
  61 static void EndThread   ( spudec_thread_t * );
  62
  63 static int  SyncPacket           ( spudec_thread_t * );
  64 static void ParsePacket          ( spudec_thread_t * );
  65 static int  ParseControlSequences( spudec_thread_t *, subpicture_t * );
  66 static int  ParseRLE             ( spudec_thread_t *, subpicture_t *, u8 * );
  67
  68 /*****************************************************************************
  69  * spudec_CreateThread: create a spu decoder thread
  70  *****************************************************************************/
  71 vlc_thread_t spudec_CreateThread( vdec_config_t * p_config )
  72 {
  73     spudec_thread_t *     p_spudec;
  74
  75     /* Allocate the memory needed to store the thread's structure */
  76     p_spudec = (spudec_thread_t *)malloc( sizeof(spudec_thread_t) );
  77
  78     if ( p_spudec == NULL )
  79     {
  80         intf_ErrMsg( "spudec error: not enough memory "
  81                      "for spudec_CreateThread() to create the new thread" );
  82         return( 0 );
  83     }
  84
  85     /*
  86      * Initialize the thread properties
  87      */
  88     p_spudec->p_config = p_config;
  89
  90     p_spudec->p_fifo = p_config->decoder_config.p_decoder_fifo;
  91
  92     /* Spawn a video output if there is none */
  93     vlc_mutex_lock( &p_vout_bank->lock );
  94
  95     if( p_vout_bank->i_count == 0 )
  96     {
  97         intf_WarnMsg( 1, "spudec: no vout present, spawning one" );
  98
  99         p_spudec->p_vout = vout_CreateThread( NULL, 0, 0 );
 100
 101         /* Everything failed */
 102         if( p_spudec->p_vout == NULL )
 103         {
 104             intf_Msg( "spudec: can't open vout, aborting" );
 105             vlc_mutex_unlock( &p_vout_bank->lock );
 106             free( p_spudec );
 107
 108             return 0;
 109         }
 110
 111         p_vout_bank->pp_vout[ p_vout_bank->i_count ] = p_spudec->p_vout;
 112         p_vout_bank->i_count++;
 113     }
 114     else
 115     {
 116         /* Take the first video output FIXME: take the best one */
 117         p_spudec->p_vout = p_vout_bank->pp_vout[ 0 ];
 118     }
 119
 120     vlc_mutex_unlock( &p_vout_bank->lock );
 121
 122     /* Spawn the spu decoder thread */
 123     if ( vlc_thread_create(&p_spudec->thread_id, "spu decoder",
 124          (vlc_thread_func_t)RunThread, (void *)p_spudec) )
 125     {
 126         intf_ErrMsg( "spudec error: can't spawn spu decoder thread" );
 127         free( p_spudec );
 128         return 0;
 129     }
 130
 131     return( p_spudec->thread_id );
 132 }
 133
 134 /* following functions are local */
 135
 136 /*****************************************************************************
 137  * InitThread: initialize spu decoder thread
 138  *****************************************************************************
 139  * This function is called from RunThread and performs the second step of the
 140  * initialization. It returns 0 on success. Note that the thread's flag are not
 141  * modified inside this function.
 142  *****************************************************************************/
 143 static int InitThread( spudec_thread_t *p_spudec )
 144 {
 145     p_spudec->p_config->decoder_config.pf_init_bit_stream(
 146             &p_spudec->bit_stream,
 147             p_spudec->p_config->decoder_config.p_decoder_fifo, NULL, NULL );
 148
 149     /* Mark thread as running and return */
 150     return( 0 );
 151 }
 152
 153 /*****************************************************************************
 154  * RunThread: spu decoder thread
 155  *****************************************************************************
 156  * spu decoder thread. This function only returns when the thread is
 157  * terminated.
 158  *****************************************************************************/
 159 static void RunThread( spudec_thread_t *p_spudec )
 160 {
 161     intf_WarnMsg( 3, "spudec: spu decoder thread %i spawned", getpid() );
 162
 163     /*
 164      * Initialize thread and free configuration
 165      */
 166     p_spudec->p_fifo->b_error = InitThread( p_spudec );
 167
 168     /*
 169      * Main loop - it is not executed if an error occured during
 170      * initialization
 171      */
 172     while( (!p_spudec->p_fifo->b_die) && (!p_spudec->p_fifo->b_error) )
 173     {
 174         if( !SyncPacket( p_spudec ) )
 175         {
 176             ParsePacket( p_spudec );
 177         }
 178     }
 179
 180     /*
 181      * Error loop
 182      */
 183     if( p_spudec->p_fifo->b_error )
 184     {
 185         ErrorThread( p_spudec );
 186     }
 187
 188     /* End of thread */
 189     intf_WarnMsg( 3, "spudec: destroying spu decoder thread %i", getpid() );
 190     EndThread( p_spudec );
 191 }
 192
 193 /*****************************************************************************
 194  * ErrorThread: RunThread() error loop
 195  *****************************************************************************
 196  * This function is called when an error occured during thread main's loop. The
 197  * thread can still receive feed, but must be ready to terminate as soon as
 198  * possible.
 199  *****************************************************************************/
 200 static void ErrorThread( spudec_thread_t *p_spudec )
 201 {
 202     /* We take the lock, because we are going to read/write the start/end
 203      * indexes of the decoder fifo */
 204     vlc_mutex_lock( &p_spudec->p_fifo->data_lock );
 205
 206     /* Wait until a `die' order is sent */
 207     while( !p_spudec->p_fifo->b_die )
 208     {
 209         /* Trash all received PES packets */
 210         while( !DECODER_FIFO_ISEMPTY(*p_spudec->p_fifo) )
 211         {
 212             p_spudec->p_fifo->pf_delete_pes( p_spudec->p_fifo->p_packets_mgt,
 213                     DECODER_FIFO_START(*p_spudec->p_fifo) );
 214             DECODER_FIFO_INCSTART( *p_spudec->p_fifo );
 215         }
 216
 217         /* Waiting for the input thread to put new PES packets in the fifo */
 218         vlc_cond_wait( &p_spudec->p_fifo->data_wait,
 219                        &p_spudec->p_fifo->data_lock );
 220     }
 221
 222     /* We can release the lock before leaving */
 223     vlc_mutex_unlock( &p_spudec->p_fifo->data_lock );
 224 }
 225
 226 /*****************************************************************************
 227  * EndThread: thread destruction
 228  *****************************************************************************
 229  * This function is called when the thread ends after a sucessful
 230  * initialization.
 231  *****************************************************************************/
 232 static void EndThread( spudec_thread_t *p_spudec )
 233 {
 234     free( p_spudec->p_config );
 235     free( p_spudec );
 236 }
 237
 238 /*****************************************************************************
 239  * SyncPacket: get in sync with the stream
 240  *****************************************************************************
 241  * This function makes a few sanity checks and returns 0 if it looks like we
 242  * are at the beginning of a subpicture packet.
 243  *****************************************************************************/
 244 static int SyncPacket( spudec_thread_t *p_spudec )
 245 {
 246     /* Re-align the buffer on an 8-bit boundary */
 247     RealignBits( &p_spudec->bit_stream );
 248
 249     /* The total SPU packet size, often bigger than a PS packet */
 250     p_spudec->i_spu_size = GetBits( &p_spudec->bit_stream, 16 );
 251
 252     /* The RLE stuff size (remove 4 because we just read 32 bits) */
 253     p_spudec->i_rle_size = ShowBits( &p_spudec->bit_stream, 16 ) - 4;
 254
 255     /* If the values we got are a bit strange, skip packet */
 256     if( !p_spudec->i_spu_size
 257          || ( p_spudec->i_rle_size >= p_spudec->i_spu_size ) )
 258     {
 259         return( 1 );
 260     }
 261
 262     RemoveBits( &p_spudec->bit_stream, 16 );
 263
 264     return( 0 );
 265 }
 266
 267 /*****************************************************************************
 268  * ParsePacket: parse an SPU packet and send it to the video output
 269  *****************************************************************************
 270  * This function parses the SPU packet and, if valid, sends it to the
 271  * video output.
 272  *****************************************************************************/
 273 static void ParsePacket( spudec_thread_t *p_spudec )
 274 {
 275     subpicture_t * p_spu;
 276     u8           * p_src;
 277     unsigned int   i_offset;
 278
 279     intf_WarnMsg( 3, "spudec: trying to gather a 0x%.2x long subtitle",
 280                   p_spudec->i_spu_size );
 281
 282     /* We cannot display a subpicture with no date */
 283     if( DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts == 0 )
 284     {
 285         intf_WarnMsg( 3, "spudec error: subtitle without a date" );
 286         return;
 287     }
 288
 289     /* Allocate the subpicture internal data. */
 290     p_spu = vout_CreateSubPicture( p_spudec->p_vout, DVD_SUBPICTURE,
 291                                    p_spudec->i_rle_size * 4 );
 292     /* Rationale for the "p_spudec->i_rle_size * 4": we are going to
 293      * expand the RLE stuff so that we won't need to read nibbles later
 294      * on. This will speed things up a lot. Plus, we'll only need to do
 295      * this stupid interlacing stuff once. */
 296
 297     if( p_spu == NULL )
 298     {
 299         return;
 300     }
 301
 302     /* Get display time now. If we do it later, we may miss the PTS. */
 303     p_spudec->i_pts = DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts;
 304
 305     /* Allocate the temporary buffer we will parse */
 306     p_src = malloc( p_spudec->i_rle_size );
 307
 308     if( p_src == NULL )
 309     {
 310         intf_ErrMsg( "spudec error: could not allocate p_src" );
 311         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 312         return;
 313     }
 314
 315     /* Get RLE data */
 316     for( i_offset = 0;
 317          i_offset + SPU_CHUNK_SIZE < p_spudec->i_rle_size;
 318          i_offset += SPU_CHUNK_SIZE )
 319     {
 320         GetChunk( &p_spudec->bit_stream, p_src + i_offset, SPU_CHUNK_SIZE );
 321
 322         /* Abort subtitle parsing if we were requested to stop */
 323         if( p_spudec->p_fifo->b_die )
 324         {
 325             free( p_src );
 326             vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 327             return;
 328         }
 329     }
 330
 331     GetChunk( &p_spudec->bit_stream, p_src + i_offset,
 332               p_spudec->i_rle_size - i_offset );
 333
 334 #if 0
 335     /* Dump the subtitle info */
 336     intf_WarnHexDump( 5, p_spu->p_data, p_spudec->i_rle_size );
 337 #endif
 338
 339     /* Getting the control part */
 340     if( ParseControlSequences( p_spudec, p_spu ) )
 341     {
 342         /* There was a parse error, delete the subpicture */
 343         free( p_src );
 344         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 345         return;
 346     }
 347
 348     /* At this point, no more GetBit() command is needed, so we have all
 349      * the data we need to tell whether the subtitle is valid. Thus we
 350      * try to display it and we ignore b_die. */
 351
 352     if( ParseRLE( p_spudec, p_spu, p_src ) )
 353     {
 354         /* There was a parse error, delete the subpicture */
 355         free( p_src );
 356         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 357         return;
 358     }
 359
 360     intf_WarnMsg( 3, "spudec: total size: 0x%x, RLE offsets: 0x%x 0x%x",
 361                   p_spudec->i_spu_size,
 362                   p_spu->type.spu.i_offset[0], p_spu->type.spu.i_offset[1] );
 363
 364     /* SPU is finished - we can ask the video output to display it */
 365     vout_DisplaySubPicture( p_spudec->p_vout, p_spu );
 366
 367     /* Clean up */
 368     free( p_src );
 369 }
 370
 371 /*****************************************************************************
 372  * ParseControlSequences: parse all SPU control sequences
 373  *****************************************************************************
 374  * This is the most important part in SPU decoding. We get dates, palette
 375  * information, coordinates, and so on. For more information on the
 376  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 377  *****************************************************************************/
 378 static int ParseControlSequences( spudec_thread_t *p_spudec,
 379                                   subpicture_t * p_spu )
 380 {
 381     /* Our current index in the SPU packet */
 382     int i_index = p_spudec->i_rle_size + 4;
 383
 384     /* The next start-of-control-sequence index and the previous one */
 385     int i_next_seq, i_cur_seq;
 386
 387     /* Command time and date */
 388     u8  i_command;
 389     int i_date;
 390
 391     /* XXX: temporary variables */
 392     boolean_t b_force_display = 0;
 393
 394     /* Initialize the structure */
 395     p_spu->i_start = p_spu->i_stop = 0;
 396     p_spu->b_ephemer = 0;
 397
 398     do
 399     {
 400         /* Get the control sequence date */
 401         i_date = GetBits( &p_spudec->bit_stream, 16 );
 402
 403         /* Next offset */
 404         i_cur_seq = i_index;
 405         i_next_seq = GetBits( &p_spudec->bit_stream, 16 );
 406
 407         /* Skip what we just read */
 408         i_index += 4;
 409
 410         do
 411         {
 412             i_command = GetBits( &p_spudec->bit_stream, 8 );
 413             i_index++;
 414
 415             switch( i_command )
 416             {
 417                 case SPU_CMD_FORCE_DISPLAY:
 418
 419                     /* 00 (force displaying) */
 420                     p_spu->i_start = p_spudec->i_pts + ( i_date * 11000 );
 421                     b_force_display = 1;
 422
 423                     break;
 424
 425                 /* Convert the dates in seconds to PTS values */
 426                 case SPU_CMD_START_DISPLAY:
 427
 428                     /* 01 (start displaying) */
 429                     p_spu->i_start = p_spudec->i_pts + ( i_date * 11000 );
 430
 431                     break;
 432
 433                 case SPU_CMD_STOP_DISPLAY:
 434
 435                     /* 02 (stop displaying) */
 436                     p_spu->i_stop = p_spudec->i_pts + ( i_date * 11000 );
 437
 438                     break;
 439
 440                 case SPU_CMD_SET_PALETTE:
 441
 442                     /* 03xxxx (palette) - trashed */
 443                     RemoveBits( &p_spudec->bit_stream, 16 );
 444                     i_index += 2;
 445
 446                     break;
 447
 448                 case SPU_CMD_SET_ALPHACHANNEL:
 449
 450                     /* 04xxxx (alpha channel) - trashed */
 451                     RemoveBits( &p_spudec->bit_stream, 16 );
 452                     i_index += 2;
 453
 454                     break;
 455
 456                 case SPU_CMD_SET_COORDINATES:
 457
 458                     /* 05xxxyyyxxxyyy (coordinates) */
 459                     p_spu->i_x = GetBits( &p_spudec->bit_stream, 12 );
 460                     p_spu->i_width = GetBits( &p_spudec->bit_stream, 12 )
 461                                       - p_spu->i_x + 1;
 462
 463                     p_spu->i_y = GetBits( &p_spudec->bit_stream, 12 );
 464                     p_spu->i_height = GetBits( &p_spudec->bit_stream, 12 )
 465                                        - p_spu->i_y + 1;
 466
 467                     i_index += 6;
 468
 469                     break;
 470
 471                 case SPU_CMD_SET_OFFSETS:
 472
 473                     /* 06xxxxyyyy (byte offsets) */
 474                     p_spu->type.spu.i_offset[0] =
 475                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 476
 477                     p_spu->type.spu.i_offset[1] =
 478                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 479
 480                     i_index += 4;
 481
 482                     break;
 483
 484                 case SPU_CMD_END:
 485
 486                     /* ff (end) */
 487                     break;
 488
 489                 default:
 490
 491                     /* xx (unknown command) */
 492                     intf_ErrMsg( "spudec error: unknown command 0x%.2x",
 493                                  i_command );
 494                     return( 1 );
 495             }
 496
 497             /* We need to check for quit commands here */
 498             if( p_spudec->p_fifo->b_die )
 499             {
 500                 return( 1 );
 501             }
 502
 503         } while( i_command != SPU_CMD_END );
 504
 505     } while( i_index == i_next_seq );
 506
 507     /* Check that the next sequence index matches the current one */
 508     if( i_next_seq != i_cur_seq )
 509     {
 510         intf_ErrMsg( "spudec error: index mismatch (0x%.4x != 0x%.4x)",
 511                      i_next_seq, i_cur_seq );
 512         return( 1 );
 513     }
 514
 515     if( i_index > p_spudec->i_spu_size )
 516     {
 517         intf_ErrMsg( "spudec error: uh-oh, we went too far (0x%.4x > 0x%.4x)",
 518                      i_index, p_spudec->i_spu_size );
 519         return( 1 );
 520     }
 521
 522     if( !p_spu->i_start )
 523     {
 524         intf_ErrMsg( "spudec error: no `start display' command" );
 525     }
 526
 527     if( !p_spu->i_stop )
 528     {
 529         /* This subtitle will live for 5 seconds or until the next subtitle */
 530         p_spu->i_stop = p_spu->i_start + 500 * 11000;
 531         p_spu->b_ephemer = 1;
 532     }
 533
 534     /* Get rid of padding bytes */
 535     switch( p_spudec->i_spu_size - i_index )
 536     {
 537         /* Zero or one padding byte, quite usual */
 538         case 1:
 539             RemoveBits( &p_spudec->bit_stream, 8 );
 540             i_index++;
 541         case 0:
 542             break;
 543
 544         /* More than one padding byte - this is very strange, but
 545          * we can deal with it */
 546         default:
 547             intf_WarnMsg( 2, "spudec warning: %i padding bytes, we usually "
 548                              "get 0 or 1 of them",
 549                           p_spudec->i_spu_size - i_index );
 550
 551             while( i_index < p_spudec->i_spu_size )
 552             {
 553                 RemoveBits( &p_spudec->bit_stream, 8 );
 554                 i_index++;
 555             }
 556
 557             break;
 558     }
 559
 560     if( b_force_display )
 561     {
 562         intf_ErrMsg( "spudec: \"force display\" command" );
 563         intf_ErrMsg( "spudec: send mail to <sam@zoy.org> if you "
 564                      "want to help debugging this" );
 565     }
 566
 567     /* Successfully parsed ! */
 568     return( 0 );
 569 }
 570
 571 /*****************************************************************************
 572  * ParseRLE: parse the RLE part of the subtitle
 573  *****************************************************************************
 574  * This part parses the subtitle graphical data and stores it in a more
 575  * convenient structure for later decoding. For more information on the
 576  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 577  *****************************************************************************/
 578 static int ParseRLE( spudec_thread_t *p_spudec,
 579                      subpicture_t * p_spu, u8 * p_src )
 580 {
 581     unsigned int i_code;
 582
 583     unsigned int i_width = p_spu->i_width;
 584     unsigned int i_height = p_spu->i_height;
 585     unsigned int i_x, i_y;
 586
 587     u16 *p_dest = (u16 *)p_spu->p_data;
 588
 589     /* The subtitles are interlaced, we need two offsets */
 590     unsigned int  i_id = 0;                   /* Start on the even SPU layer */
 591     unsigned int  pi_table[ 2 ];
 592     unsigned int *pi_offset;
 593
 594     boolean_t b_empty_top = 1,
 595               b_empty_bottom = 0;
 596     unsigned int i_skipped_top = 0,
 597                  i_skipped_bottom = 0;
 598
 599     pi_table[ 0 ] = p_spu->type.spu.i_offset[ 0 ] << 1;
 600     pi_table[ 1 ] = p_spu->type.spu.i_offset[ 1 ] << 1;
 601
 602     for( i_y = 0 ; i_y < i_height ; i_y++ )
 603     {
 604         pi_offset = pi_table + i_id;
 605
 606         for( i_x = 0 ; i_x < i_width ; i_x += i_code >> 2 )
 607         {
 608             i_code = AddNibble( 0, p_src, pi_offset );
 609
 610             if( i_code < 0x04 )
 611             {
 612                 i_code = AddNibble( i_code, p_src, pi_offset );
 613
 614                 if( i_code < 0x10 )
 615                 {
 616                     i_code = AddNibble( i_code, p_src, pi_offset );
 617
 618                     if( i_code < 0x040 )
 619                     {
 620                         i_code = AddNibble( i_code, p_src, pi_offset );
 621
 622                         if( i_code < 0x0100 )
 623                         {
 624                             /* If the 14 first bits are set to 0, then it's a
 625                              * new line. We emulate it. */
 626                             if( i_code < 0x0004 )
 627                             {
 628                                 i_code |= ( i_width - i_x ) << 2;
 629                             }
 630                             else
 631                             {
 632                                 /* We have a boo boo ! */
 633                                 intf_ErrMsg( "spudec error: unknown RLE code "
 634                                              "0x%.4x", i_code );
 635                                 return( 1 );
 636                             }
 637                         }
 638                     }
 639                 }
 640             }
 641
 642             if( ( (i_code >> 2) + i_x + i_y * i_width ) > i_height * i_width )
 643             {
 644                 intf_ErrMsg( "spudec error: out of bounds, %i at (%i,%i) is "
 645                              "out of %ix%i",
 646                              i_code >> 2, i_x, i_y, i_width, i_height );
 647                 return( 1 );
 648             }
 649
 650             if( i_code == (i_width << 2) ) /* FIXME: we assume 0 is transp */
 651             {
 652                 if( b_empty_top )
 653                 {
 654                     /* This is a blank top line, we skip it */
 655                     i_skipped_top++;
 656                 }
 657                 else
 658                 {
 659                     /* We can't be sure the current lines will be skipped,
 660                      * so we store the code just in case. */
 661                     *p_dest++ = i_code;
 662
 663                     b_empty_bottom = 1;
 664                     i_skipped_bottom++;
 665                 }
 666             }
 667             else
 668             {
 669                 /* We got a valid code, store it */
 670                 *p_dest++ = i_code;
 671
 672                 /* Valid code means no blank line */
 673                 b_empty_top = 0;
 674                 b_empty_bottom = 0;
 675                 i_skipped_bottom = 0;
 676             }
 677         }
 678
 679         /* Check that we didn't go too far */
 680         if( i_x > i_width )
 681         {
 682             intf_ErrMsg( "spudec error: i_x overflowed, %i > %i",
 683                          i_x, i_width );
 684             return( 1 );
 685         }
 686
 687         /* Byte-align the stream */
 688         if( *pi_offset & 0x1 )
 689         {
 690             (*pi_offset)++;
 691         }
 692
 693         /* Swap fields */
 694         i_id = ~i_id & 0x1;
 695     }
 696
 697     /* We shouldn't get any padding bytes */
 698     if( i_y < i_height )
 699     {
 700         intf_ErrMsg( "spudec: padding bytes found in RLE sequence" );
 701         intf_ErrMsg( "spudec: send mail to <sam@zoy.org> if you "
 702                      "want to help debugging this" );
 703
 704         /* Skip them just in case */
 705         while( i_y < i_height )
 706         {
 707             *p_dest++ = i_width << 2;
 708             i_y++;
 709         }
 710
 711         return( 1 );
 712     }
 713
 714     intf_WarnMsg( 3, "spudec: valid subtitle, size: %ix%i, position: %i,%i",
 715                   p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y );
 716
 717     /* Crop if necessary */
 718     if( i_skipped_top || i_skipped_bottom )
 719     {
 720         p_spu->i_y += i_skipped_top;
 721         p_spu->i_height -= i_skipped_top + i_skipped_bottom;
 722
 723         intf_WarnMsg( 3, "spudec: cropped to: %ix%i, position: %i,%i",
 724                       p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y );
 725     }
 726
 727     return( 0 );
 728 }
 729