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 = ShowBits( &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     RemoveBits( &p_spudec->bit_stream, 16 );
 225
 226     return( 0 );
 227 }
 228
 229 /*****************************************************************************
 230  * ParsePacket: parse an SPU packet and send it to the video output
 231  *****************************************************************************
 232  * This function parses the SPU packet and, if valid, sends it to the
 233  * video output.
 234  *****************************************************************************/
 235 static void ParsePacket( spudec_thread_t *p_spudec )
 236 {
 237     subpicture_t * p_spu;
 238     u8           * p_src;
 239
 240     /* We cannot display a subpicture with no date */
 241     if( DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts == 0 )
 242     {
 243         return;
 244     }
 245
 246     /* Allocate the subpicture internal data. */
 247     p_spu = vout_CreateSubPicture( p_spudec->p_vout, DVD_SUBPICTURE,
 248                                    p_spudec->i_rle_size * 4 );
 249     /* Rationale for the "p_spudec->i_rle_size * 4": we are going to
 250      * expand the RLE stuff so that we won't need to read nibbles later
 251      * on. This will speed things up a lot. Plus, we'll only need to do
 252      * this stupid interlacing stuff once. */
 253
 254     if( p_spu == NULL )
 255     {
 256         return;
 257     }
 258
 259     /* Get display time now. If we do it later, we may miss a PTS. */
 260     p_spu->begin_date = p_spu->end_date
 261                     = DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts;
 262
 263     /* Allocate the temporary buffer we will parse */
 264     p_src = malloc( p_spudec->i_rle_size );
 265
 266     if( p_src == NULL )
 267     {
 268         intf_ErrMsg( "spudec error: could not allocate p_src" );
 269         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 270         return;
 271     }
 272
 273     /* Get RLE data */
 274     GetChunk( &p_spudec->bit_stream, p_src, p_spudec->i_rle_size );
 275
 276 #if 0
 277     /* Dump the subtitle info */
 278     intf_WarnHexDump( 0, p_spu->p_data, p_spudec->i_rle_size );
 279 #endif
 280
 281     /* Getting the control part */
 282     if( ParseControlSequences( p_spudec, p_spu ) )
 283     {
 284         /* There was a parse error, delete the subpicture */
 285         free( p_src );
 286         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 287         return;
 288     }
 289
 290     if( ParseRLE( p_src, p_spu ) )
 291     {
 292         /* There was a parse error, delete the subpicture */
 293         free( p_src );
 294         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 295         return;
 296     }
 297
 298     intf_WarnMsg( 1, "spudec: got a valid %ix%i subtitle at (%i,%i), "
 299                      "RLE offsets: 0x%x 0x%x",
 300                   p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y,
 301                   p_spu->type.spu.i_offset[0], p_spu->type.spu.i_offset[1] );
 302
 303     /* SPU is finished - we can tell the video output to display it */
 304     vout_DisplaySubPicture( p_spudec->p_vout, p_spu );
 305
 306     /* Clean up */
 307     free( p_src );
 308 }
 309
 310 /*****************************************************************************
 311  * ParseControlSequences: parse all SPU control sequences
 312  *****************************************************************************
 313  * This is the most important part in SPU decoding. We get dates, palette
 314  * information, coordinates, and so on. For more information on the
 315  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 316  *****************************************************************************/
 317 static int ParseControlSequences( spudec_thread_t *p_spudec,
 318                                   subpicture_t * p_spu )
 319 {
 320     /* Our current index in the SPU packet */
 321     int i_index = p_spudec->i_rle_size + 4;
 322
 323     /* The next start-of-control-sequence index and the previous one */
 324     int i_next_index = 0, i_prev_index;
 325
 326     /* Command time and date */
 327     u8  i_command;
 328     int i_date;
 329
 330     do
 331     {
 332         /* Get the control sequence date */
 333         i_date = GetBits( &p_spudec->bit_stream, 16 );
 334
 335         /* Next offset */
 336         i_prev_index = i_next_index;
 337         i_next_index = GetBits( &p_spudec->bit_stream, 16 );
 338
 339         /* Skip what we just read */
 340         i_index += 4;
 341
 342         do
 343         {
 344             i_command = GetBits( &p_spudec->bit_stream, 8 );
 345             i_index++;
 346
 347             switch( i_command )
 348             {
 349                 case SPU_CMD_FORCE_DISPLAY:
 350
 351                     /* 00 (force displaying) */
 352
 353                     break;
 354
 355                 /* FIXME: here we have to calculate dates. It's around
 356                  * i_date * 12000 but I don't know how much exactly. */
 357                 case SPU_CMD_START_DISPLAY:
 358
 359                     /* 01 (start displaying) */
 360                     p_spu->begin_date += ( i_date * 11000 );
 361
 362                     break;
 363
 364                 case SPU_CMD_STOP_DISPLAY:
 365
 366                     /* 02 (stop displaying) */
 367                     p_spu->end_date += ( i_date * 11000 );
 368
 369                     break;
 370
 371                 case SPU_CMD_SET_PALETTE:
 372
 373                     /* 03xxxx (palette) - trashed */
 374                     RemoveBits( &p_spudec->bit_stream, 16 );
 375                     i_index += 2;
 376
 377                     break;
 378
 379                 case SPU_CMD_SET_ALPHACHANNEL:
 380
 381                     /* 04xxxx (alpha channel) - trashed */
 382                     RemoveBits( &p_spudec->bit_stream, 16 );
 383                     i_index += 2;
 384
 385                     break;
 386
 387                 case SPU_CMD_SET_COORDINATES:
 388
 389                     /* 05xxxyyyxxxyyy (coordinates) */
 390                     p_spu->i_x = GetBits( &p_spudec->bit_stream, 12 );
 391                     p_spu->i_width = GetBits( &p_spudec->bit_stream, 12 )
 392                                       - p_spu->i_x + 1;
 393
 394                     p_spu->i_y = GetBits( &p_spudec->bit_stream, 12 );
 395                     p_spu->i_height = GetBits( &p_spudec->bit_stream, 12 )
 396                                        - p_spu->i_y + 1;
 397
 398                     i_index += 6;
 399
 400                     break;
 401
 402                 case SPU_CMD_SET_OFFSETS:
 403
 404                     /* 06xxxxyyyy (byte offsets) */
 405                     p_spu->type.spu.i_offset[0] =
 406                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 407
 408                     p_spu->type.spu.i_offset[1] =
 409                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 410
 411                     i_index += 4;
 412
 413                     break;
 414
 415                 case SPU_CMD_END:
 416
 417                     /* ff (end) */
 418
 419                     break;
 420
 421                 default:
 422
 423                     /* ?? (unknown command) */
 424                     intf_ErrMsg( "spudec error: unknown command 0x%.2x",
 425                                  i_command );
 426                     return( 1 );
 427             }
 428
 429         } while( i_command != SPU_CMD_END );
 430
 431     } while( i_index == i_next_index );
 432
 433     /* Check that the last index matches the previous one */
 434     if( i_next_index != i_prev_index )
 435     {
 436         intf_ErrMsg( "spudec error: index mismatch (0x%.4x != 0x%.4x)",
 437                      i_next_index, i_prev_index );
 438         return( 1 );
 439     }
 440
 441     if( i_index > p_spudec->i_spu_size )
 442     {
 443         intf_ErrMsg( "spudec error: uh-oh, we went too far (0x%.4x > 0x%.4x)",
 444                      i_index, p_spudec->i_spu_size );
 445         return( 1 );
 446     }
 447
 448     /* Get rid of padding bytes */
 449     switch( p_spudec->i_spu_size - i_index )
 450     {
 451         case 1:
 452
 453             RemoveBits( &p_spudec->bit_stream, 8 );
 454             i_index++;
 455
 456         case 0:
 457
 458             /* Zero or one padding byte, quite usual */
 459
 460             break;
 461
 462         default:
 463
 464             /* More than one padding byte - this is very strange, but
 465              * we can deal with it */
 466             intf_WarnMsg( 2, "spudec warning: %i padding bytes",
 467                           p_spudec->i_spu_size - i_index );
 468
 469             while( i_index < p_spudec->i_spu_size )
 470             {
 471                 RemoveBits( &p_spudec->bit_stream, 8 );
 472                 i_index++;
 473             }
 474
 475             break;
 476     }
 477
 478     /* Successfully parsed ! */
 479     return( 0 );
 480 }
 481
 482 /*****************************************************************************
 483  * ParseRLE: parse the RLE part of the subtitle
 484  *****************************************************************************
 485  * This part parses the subtitle graphical data and stores it in a more
 486  * convenient structure for later decoding. For more information on the
 487  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 488  *****************************************************************************/
 489 static int ParseRLE( u8 *p_src, subpicture_t * p_spu )
 490 {
 491     unsigned int i_code;
 492     unsigned int i_id = 0;
 493
 494     unsigned int i_width = p_spu->i_width;
 495     unsigned int i_height = p_spu->i_height;
 496     unsigned int i_x, i_y;
 497
 498     u16 *p_dest = (u16 *)p_spu->p_data;
 499
 500     /* The subtitles are interlaced, we need two offsets */
 501     unsigned int  pi_table[2];
 502     unsigned int *pi_offset;
 503     pi_table[0] = p_spu->type.spu.i_offset[0] << 1;
 504     pi_table[1] = p_spu->type.spu.i_offset[1] << 1;
 505
 506     for( i_y = 0 ; i_y < i_height ; i_y++ )
 507     {
 508         pi_offset = pi_table + i_id;
 509
 510         for( i_x = 0 ; i_x < i_width ; i_x += i_code >> 2 )
 511         {
 512             i_code = AddNibble( 0, p_src, pi_offset );
 513
 514             if( i_code < 0x04 )
 515             {
 516                 i_code = AddNibble( i_code, p_src, pi_offset );
 517
 518                 if( i_code < 0x10 )
 519                 {
 520                     i_code = AddNibble( i_code, p_src, pi_offset );
 521
 522                     if( i_code < 0x040 )
 523                     {
 524                         i_code = AddNibble( i_code, p_src, pi_offset );
 525
 526                         if( i_code < 0x0100 )
 527                         {
 528                             /* If the 14 first bits are set to 0, then it's a
 529                              * new line. We emulate it. */
 530                             if( i_code < 0x0004 )
 531                             {
 532                                 i_code |= ( i_width - i_x ) << 2;
 533                             }
 534                             else
 535                             {
 536                                 /* We have a boo boo ! */
 537                                 intf_ErrMsg( "spudec error: unknown code %.4x",
 538                                              i_code );
 539                                 return( 1 );
 540                             }
 541                         }
 542                     }
 543                 }
 544             }
 545
 546             if( ( (i_code >> 2) + i_x + i_y * i_width ) > i_height * i_width )
 547             {
 548                 intf_ErrMsg( "spudec error: out of bounds, %i at (%i,%i) is "
 549                              "out of %ix%i",
 550                              i_code >> 2, i_x, i_y, i_width, i_height);
 551                 return( 1 );
 552             }
 553
 554             /* We got a valid code, store it */
 555             *p_dest++ = i_code;
 556         }
 557
 558         /* Check that we didn't go too far */
 559         if( i_x > i_width )
 560         {
 561             intf_ErrMsg( "spudec error: i_x overflowed, %i > %i",
 562                          i_x, i_width );
 563             return( 1 );
 564         }
 565
 566         /* Byte-align the stream */
 567         if( *pi_offset & 0x1 )
 568         {
 569             (*pi_offset)++;
 570         }
 571
 572         /* Swap fields */
 573         i_id = ~i_id & 0x1;
 574     }
 575
 576     /* FIXME: we shouldn't need these padding bytes */
 577     while( i_y < i_height )
 578     {
 579         *p_dest++ = i_width << 2;
 580         i_y++;
 581     }
 582
 583     return( 0 );
 584 }
 585