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  *
   6  * Authors: Samuel Hocevar <sam@zoy.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  21  *****************************************************************************/
  22
  23 /*****************************************************************************
  24  * Preamble
  25  *****************************************************************************/
  26 #include "defs.h"
  27
  28 #include <stdlib.h>                                      /* malloc(), free() */
  29 #include <unistd.h>                                              /* getpid() */
  30
  31 #include "config.h"
  32 #include "common.h"
  33 #include "threads.h"
  34 #include "mtime.h"
  35
  36 #include "intf_msg.h"
  37
  38 #include "stream_control.h"
  39 #include "input_ext-dec.h"
  40
  41 #include "video.h"
  42 #include "video_output.h"
  43
  44 #include "spu_decoder.h"
  45
  46 /*****************************************************************************
  47  * Local prototypes
  48  *****************************************************************************/
  49 static int  InitThread  ( spudec_thread_t * );
  50 static void RunThread   ( spudec_thread_t * );
  51 static void ErrorThread ( spudec_thread_t * );
  52 static void EndThread   ( spudec_thread_t * );
  53
  54 static int  SyncPacket           ( spudec_thread_t * );
  55 static void ParsePacket          ( spudec_thread_t * );
  56 static int  ParseControlSequences( spudec_thread_t *, subpicture_t * );
  57 static int  ParseRLE             ( u8 *,              subpicture_t * );
  58
  59 /*****************************************************************************
  60  * spudec_CreateThread: create a spu decoder thread
  61  *****************************************************************************/
  62 vlc_thread_t spudec_CreateThread( vdec_config_t * p_config )
  63 {
  64     spudec_thread_t *     p_spudec;
  65
  66     /* Allocate the memory needed to store the thread's structure */
  67     p_spudec = (spudec_thread_t *)malloc( sizeof(spudec_thread_t) );
  68
  69     if ( p_spudec == NULL )
  70     {
  71         intf_ErrMsg( "spudec error: not enough memory "
  72                      "for spudec_CreateThread() to create the new thread" );
  73         return( 0 );
  74     }
  75
  76     /*
  77      * Initialize the thread properties
  78      */
  79     p_spudec->p_config = p_config;
  80     p_spudec->p_fifo = p_config->decoder_config.p_decoder_fifo;
  81
  82     /* Get the video output informations */
  83     p_spudec->p_vout = p_config->p_vout;
  84
  85     /* Spawn the spu decoder thread */
  86     if ( vlc_thread_create(&p_spudec->thread_id, "spu decoder",
  87          (vlc_thread_func_t)RunThread, (void *)p_spudec) )
  88     {
  89         intf_ErrMsg( "spudec error: can't spawn spu decoder thread" );
  90         free( p_spudec );
  91         return( 0 );
  92     }
  93
  94     return( p_spudec->thread_id );
  95 }
  96
  97 /* following functions are local */
  98
  99 /*****************************************************************************
 100  * InitThread: initialize spu decoder thread
 101  *****************************************************************************
 102  * This function is called from RunThread and performs the second step of the
 103  * initialization. It returns 0 on success. Note that the thread's flag are not
 104  * modified inside this function.
 105  *****************************************************************************/
 106 static int InitThread( spudec_thread_t *p_spudec )
 107 {
 108     p_spudec->p_config->decoder_config.pf_init_bit_stream(
 109             &p_spudec->bit_stream,
 110             p_spudec->p_config->decoder_config.p_decoder_fifo );
 111
 112     /* Mark thread as running and return */
 113     return( 0 );
 114 }
 115
 116 /*****************************************************************************
 117  * RunThread: spu decoder thread
 118  *****************************************************************************
 119  * spu decoder thread. This function only returns when the thread is
 120  * terminated.
 121  *****************************************************************************/
 122 static void RunThread( spudec_thread_t *p_spudec )
 123 {
 124     intf_WarnMsg( 1, "spudec: spu decoder thread %i spawned", getpid() );
 125
 126     /*
 127      * Initialize thread and free configuration
 128      */
 129     p_spudec->p_fifo->b_error = InitThread( p_spudec );
 130
 131     /*
 132      * Main loop - it is not executed if an error occured during
 133      * initialization
 134      */
 135     while( (!p_spudec->p_fifo->b_die) && (!p_spudec->p_fifo->b_error) )
 136     {
 137         if( !SyncPacket( p_spudec ) )
 138         {
 139             ParsePacket( p_spudec );
 140         }
 141     }
 142
 143     /*
 144      * Error loop
 145      */
 146     if( p_spudec->p_fifo->b_error )
 147     {
 148         ErrorThread( p_spudec );
 149     }
 150
 151     /* End of thread */
 152     intf_WarnMsg( 1, "spudec: destroying spu decoder thread %i", getpid() );
 153     EndThread( p_spudec );
 154 }
 155
 156 /*****************************************************************************
 157  * ErrorThread: RunThread() error loop
 158  *****************************************************************************
 159  * This function is called when an error occured during thread main's loop. The
 160  * thread can still receive feed, but must be ready to terminate as soon as
 161  * possible.
 162  *****************************************************************************/
 163 static void ErrorThread( spudec_thread_t *p_spudec )
 164 {
 165     /* We take the lock, because we are going to read/write the start/end
 166      * indexes of the decoder fifo */
 167     vlc_mutex_lock( &p_spudec->p_fifo->data_lock );
 168
 169     /* Wait until a `die' order is sent */
 170     while( !p_spudec->p_fifo->b_die )
 171     {
 172         /* Trash all received PES packets */
 173         while( !DECODER_FIFO_ISEMPTY(*p_spudec->p_fifo) )
 174         {
 175             p_spudec->p_fifo->pf_delete_pes( p_spudec->p_fifo->p_packets_mgt,
 176                     DECODER_FIFO_START(*p_spudec->p_fifo) );
 177             DECODER_FIFO_INCSTART( *p_spudec->p_fifo );
 178         }
 179
 180         /* Waiting for the input thread to put new PES packets in the fifo */
 181         vlc_cond_wait( &p_spudec->p_fifo->data_wait,
 182                        &p_spudec->p_fifo->data_lock );
 183     }
 184
 185     /* We can release the lock before leaving */
 186     vlc_mutex_unlock( &p_spudec->p_fifo->data_lock );
 187 }
 188
 189 /*****************************************************************************
 190  * EndThread: thread destruction
 191  *****************************************************************************
 192  * This function is called when the thread ends after a sucessful
 193  * initialization.
 194  *****************************************************************************/
 195 static void EndThread( spudec_thread_t *p_spudec )
 196 {
 197     free( p_spudec->p_config );
 198     free( p_spudec );
 199 }
 200
 201 /*****************************************************************************
 202  * SyncPacket: get in sync with the stream
 203  *****************************************************************************
 204  * This function makes a few sanity checks and returns 0 if it looks like we
 205  * are at the beginning of a subpicture packet.
 206  *****************************************************************************/
 207 static int SyncPacket( spudec_thread_t *p_spudec )
 208 {
 209     /* Re-align the buffer on an 8-bit boundary */
 210     RealignBits( &p_spudec->bit_stream );
 211
 212     /* The total SPU packet size, often bigger than a PS packet */
 213     p_spudec->i_spu_size = GetBits( &p_spudec->bit_stream, 16 );
 214
 215     /* The RLE stuff size (remove 4 because we just read 32 bits) */
 216     p_spudec->i_rle_size = GetBits( &p_spudec->bit_stream, 16 ) - 4;
 217
 218     /* If the values we got are a bit strange, skip packet */
 219     if( p_spudec->i_rle_size >= p_spudec->i_spu_size )
 220     {
 221         return( 1 );
 222     }
 223
 224     return( 0 );
 225 }
 226
 227 /*****************************************************************************
 228  * ParsePacket: parse an SPU packet and send it to the video output
 229  *****************************************************************************
 230  * This function parses the SPU packet and, if valid, sends it to the
 231  * video output.
 232  *****************************************************************************/
 233 static void ParsePacket( spudec_thread_t *p_spudec )
 234 {
 235     subpicture_t * p_spu;
 236     u8           * p_source;
 237
 238     /* We cannot display a subpicture with no date */
 239     if( DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts == 0 )
 240     {
 241         return;
 242     }
 243
 244     /* Allocate the subpicture internal data. */
 245     p_spu = vout_CreateSubPicture( p_spudec->p_vout, DVD_SUBPICTURE,
 246                                    p_spudec->i_rle_size * 4 );
 247     /* Rationale for the "p_spudec->i_rle_size * 4": we are going to
 248      * expand the RLE stuff so that we won't need to read nibbles later
 249      * on. This will speed things up a lot. Plus, we won't need to do
 250      * this stupid interlacing stuff. */
 251
 252     if( p_spu == NULL )
 253     {
 254         return;
 255     }
 256
 257     /* Get display time now. If we do it later, we may miss a PTS. */
 258     p_spu->begin_date = p_spu->end_date
 259                     = DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts;
 260
 261     /* Allocate the temporary buffer we will parse */
 262     p_source = malloc( p_spudec->i_rle_size );
 263
 264     if( p_source == NULL )
 265     {
 266         intf_ErrMsg( "spudec error: could not allocate p_source" );
 267         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 268         return;
 269     }
 270
 271     /* Get RLE data */
 272     GetChunk( &p_spudec->bit_stream, p_source, p_spudec->i_rle_size );
 273
 274 #if 0
 275     /* Dump the subtitle info */
 276     intf_WarnHexDump( 0, p_spu->p_data, p_spudec->i_rle_size );
 277 #endif
 278
 279     /* Getting the control part */
 280     if( ParseControlSequences( p_spudec, p_spu ) )
 281     {
 282         /* There was a parse error, delete the subpicture */
 283         free( p_source );
 284         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 285         return;
 286     }
 287
 288     intf_WarnMsg( 1, "spudec: got a valid %ix%i subtitle at (%i,%i), "
 289                      "RLE offsets: 0x%x 0x%x",
 290                   p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y,
 291                   p_spu->type.spu.i_offset[0], p_spu->type.spu.i_offset[1] );
 292
 293     if( ParseRLE( p_source, p_spu ) )
 294     {
 295         /* There was a parse error, delete the subpicture */
 296         free( p_source );
 297         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 298         return;
 299     }
 300
 301     /* SPU is finished - we can tell the video output to display it */
 302     vout_DisplaySubPicture( p_spudec->p_vout, p_spu );
 303
 304     /* Clean up */
 305     free( p_source );
 306 }
 307
 308 /*****************************************************************************
 309  * ParseControlSequences: parse all SPU control sequences
 310  *****************************************************************************
 311  * This is the most important part in SPU decoding. We get dates, palette
 312  * information, coordinates, and so on. For more information on the
 313  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 314  *****************************************************************************/
 315 static int ParseControlSequences( spudec_thread_t *p_spudec,
 316                                   subpicture_t * p_spu )
 317 {
 318     /* Our current index in the SPU packet */
 319     int i_index = p_spudec->i_rle_size + 4;
 320
 321     /* The next start-of-control-sequence index and the previous one */
 322     int i_next_index = 0, i_prev_index;
 323
 324     /* Command time and date */
 325     u8  i_command;
 326     int i_date;
 327
 328     do
 329     {
 330         /* Get the control sequence date */
 331         i_date = GetBits( &p_spudec->bit_stream, 16 );
 332
 333         /* Next offset */
 334         i_prev_index = i_next_index;
 335         i_next_index = GetBits( &p_spudec->bit_stream, 16 );
 336
 337         /* Skip what we just read */
 338         i_index += 4;
 339
 340         do
 341         {
 342             i_command = GetBits( &p_spudec->bit_stream, 8 );
 343             i_index++;
 344
 345             switch( i_command )
 346             {
 347                 case SPU_CMD_FORCE_DISPLAY:
 348
 349                     /* 00 (force displaying) */
 350
 351                     break;
 352
 353                 /* FIXME: here we have to calculate dates. It's around
 354                  * i_date * 12000 but I don't know how much exactly. */
 355                 case SPU_CMD_START_DISPLAY:
 356
 357                     /* 01 (start displaying) */
 358                     p_spu->begin_date += ( i_date * 12000 );
 359
 360                     break;
 361
 362                 case SPU_CMD_STOP_DISPLAY:
 363
 364                     /* 02 (stop displaying) */
 365                     p_spu->end_date += ( i_date * 12000 );
 366
 367                     break;
 368
 369                 case SPU_CMD_SET_PALETTE:
 370
 371                     /* 03xxxx (palette) - trashed */
 372                     RemoveBits( &p_spudec->bit_stream, 16 );
 373                     i_index += 2;
 374
 375                     break;
 376
 377                 case SPU_CMD_SET_ALPHACHANNEL:
 378
 379                     /* 04xxxx (alpha channel) - trashed */
 380                     RemoveBits( &p_spudec->bit_stream, 16 );
 381                     i_index += 2;
 382
 383                     break;
 384
 385                 case SPU_CMD_SET_COORDINATES:
 386
 387                     /* 05xxxyyyxxxyyy (coordinates) */
 388                     p_spu->i_x = GetBits( &p_spudec->bit_stream, 12 );
 389                     p_spu->i_width = GetBits( &p_spudec->bit_stream, 12 )
 390                                       - p_spu->i_x + 1;
 391
 392                     p_spu->i_y = GetBits( &p_spudec->bit_stream, 12 );
 393                     p_spu->i_height = GetBits( &p_spudec->bit_stream, 12 )
 394                                        - p_spu->i_y + 1;
 395
 396                     i_index += 6;
 397
 398                     break;
 399
 400                 case SPU_CMD_SET_OFFSETS:
 401
 402                     /* 06xxxxyyyy (byte offsets) */
 403                     p_spu->type.spu.i_offset[0] =
 404                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 405
 406                     p_spu->type.spu.i_offset[1] =
 407                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 408
 409                     i_index += 4;
 410
 411                     break;
 412
 413                 case SPU_CMD_END:
 414
 415                     /* ff (end) */
 416
 417                     break;
 418
 419                 default:
 420
 421                     /* ?? (unknown command) */
 422                     intf_ErrMsg( "spudec error: unknown command 0x%.2x",
 423                                  i_command );
 424                     return( 1 );
 425             }
 426
 427         } while( i_command != SPU_CMD_END );
 428
 429     } while( i_index == i_next_index );
 430
 431     /* Check that the last index matches the previous one */
 432     if( i_next_index != i_prev_index )
 433     {
 434         intf_ErrMsg( "spudec error: index mismatch (0x%.4x != 0x%.4x)",
 435                      i_next_index, i_prev_index );
 436         return( 1 );
 437     }
 438
 439     if( i_index > p_spudec->i_spu_size )
 440     {
 441         intf_ErrMsg( "spudec error: uh-oh, we went too far (0x%.4x > 0x%.4x)",
 442                      i_index, p_spudec->i_spu_size );
 443         return( 1 );
 444     }
 445
 446     /* Get rid of padding bytes */
 447     switch( p_spudec->i_spu_size - i_index )
 448     {
 449         case 1:
 450
 451             RemoveBits( &p_spudec->bit_stream, 8 );
 452             i_index++;
 453
 454         case 0:
 455
 456             /* Zero or one padding byte, quite usual */
 457
 458             break;
 459
 460         default:
 461
 462             /* More than one padding byte - this is very strange, but
 463              * we can deal with it */
 464             intf_WarnMsg( 2, "spudec warning: %i padding bytes",
 465                           p_spudec->i_spu_size - i_index );
 466
 467             while( i_index < p_spudec->i_spu_size )
 468             {
 469                 RemoveBits( &p_spudec->bit_stream, 8 );
 470                 i_index++;
 471             }
 472
 473             break;
 474     }
 475
 476     /* Successfully parsed ! */
 477     return( 0 );
 478 }
 479
 480 /*****************************************************************************
 481  * ParseRLE: parse the RLE part of the subtitle
 482  *****************************************************************************
 483  * This part parses the subtitle graphical data and stores it in a more
 484  * convenient structure for later decoding. For more information on the
 485  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 486  *****************************************************************************/
 487 static int ParseRLE( u8 *p_source, subpicture_t * p_spu )
 488 {
 489     int i_code;
 490     int i_id = 0;
 491
 492     int i_width = p_spu->i_width;
 493     int i_height = p_spu->i_height;
 494     int i_x = 0, i_y = 0;
 495
 496     u16 *p_dest = (u16 *)p_spu->p_data;
 497     int pi_index[2];
 498
 499     pi_index[0] = p_spu->type.spu.i_offset[0] << 1;
 500     pi_index[1] = p_spu->type.spu.i_offset[1] << 1;
 501
 502     while( i_y < i_height )
 503     {
 504         i_code = GetNibble( p_source, pi_index + i_id );
 505
 506         if( i_code >= 0x04 )
 507         {
 508             found_code:
 509
 510             if( ((i_code >> 2) + i_x + i_y * i_width) > i_height * i_width )
 511             {
 512                 intf_ErrMsg( "spudec error: out of bounds, %i at (%i,%i) is "
 513                              "out of %ix%i",
 514                              i_code >> 2, i_x, i_y, i_width, i_height);
 515                 return( 1 );
 516             }
 517             else
 518             {
 519                 /* Store the code */
 520                 *p_dest++ = i_code;
 521
 522                 i_x += i_code >> 2;
 523             }
 524
 525             if( i_x > i_width )
 526             {
 527                 intf_ErrMsg( "spudec error: i_x overflowed, %i > %i",
 528                              i_x, i_width );
 529                 return( 1 );
 530             }
 531
 532             if( i_x == i_width )
 533             {
 534                 /* byte-align the stream */
 535                 if( pi_index[i_id] & 0x1 )
 536                 {
 537                     pi_index[i_id]++;
 538                 }
 539
 540                 i_id = ~i_id & 0x1;
 541
 542                 i_y++;
 543                 i_x = 0;
 544
 545                 if( i_y > i_height )
 546                 {
 547                     intf_ErrMsg( "spudec error: i_y overflowed at EOL, "
 548                                  "%i > %i", i_y, i_height );
 549                     return( 1 );
 550                 }
 551             }
 552
 553             continue;
 554         }
 555
 556         i_code = ( i_code << 4 ) + GetNibble( p_source, pi_index + i_id );
 557
 558         /* 00 11 xx cc */
 559         if( i_code >= 0x10 )
 560         {
 561             /* 00 01 xx cc */
 562             goto found_code;
 563         }
 564
 565         i_code = ( i_code << 4 ) + GetNibble( p_source, pi_index + i_id );
 566
 567         /* 00 00 11 xx xx cc */
 568         if( i_code >= 0x040 )
 569         {
 570             goto found_code;   /* 00 00 01 xx xx cc */
 571         }
 572
 573         i_code = ( i_code << 4 ) + GetNibble( p_source, pi_index + i_id );
 574
 575         if( i_code >= 0x0100 ) /* 00 00 00 11 xx xx xx cc */
 576         {
 577             goto found_code;   /* 00 00 00 01 xx xx xx cc */
 578         }
 579
 580         if( i_code & ~0x0003 )
 581         {
 582             /* We have a boo boo ! */
 583             intf_ErrMsg( "spudec error: unknown code 0x%.4x", i_code );
 584             return( 1 );
 585         }
 586         else
 587         {
 588             /* If the 14 first bits are 0, then it's a new line */
 589             i_code |= ( i_width - i_x ) << 2;
 590             goto found_code;
 591         }
 592     }
 593
 594     /* FIXME: we shouldn't need these padding bytes */
 595     while( i_y < i_height )
 596     {
 597         *p_dest++ = i_width << 2;
 598         i_y++;
 599     }
 600
 601     return( 0 );
 602 }
 603