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 1.36 2001/04/25 09:31:14 sam 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 #include <unistd.h>                                              /* getpid() */
  30
  31 #include <stdlib.h>                                      /* malloc(), free() */
  32 #include <string.h>                                    /* memcpy(), memset() */
  33
  34 #include "config.h"
  35 #include "common.h"
  36 #include "threads.h"
  37 #include "mtime.h"
  38
  39 #include "intf_msg.h"
  40
  41 #include "stream_control.h"
  42 #include "input_ext-dec.h"
  43
  44 #include "video.h"
  45 #include "video_output.h"
  46
  47 #include "spu_decoder.h"
  48
  49 /*****************************************************************************
  50  * Local prototypes
  51  *****************************************************************************/
  52 static int  InitThread  ( spudec_thread_t * );
  53 static void RunThread   ( spudec_thread_t * );
  54 static void ErrorThread ( spudec_thread_t * );
  55 static void EndThread   ( spudec_thread_t * );
  56
  57 static int  SyncPacket           ( spudec_thread_t * );
  58 static void ParsePacket          ( spudec_thread_t * );
  59 static int  ParseControlSequences( spudec_thread_t *, subpicture_t * );
  60 static int  ParseRLE             ( u8 *,              subpicture_t * );
  61
  62 /*****************************************************************************
  63  * spudec_CreateThread: create a spu decoder thread
  64  *****************************************************************************/
  65 vlc_thread_t spudec_CreateThread( vdec_config_t * p_config )
  66 {
  67     spudec_thread_t *     p_spudec;
  68
  69     /* Allocate the memory needed to store the thread's structure */
  70     p_spudec = (spudec_thread_t *)malloc( sizeof(spudec_thread_t) );
  71
  72     if ( p_spudec == NULL )
  73     {
  74         intf_ErrMsg( "spudec error: not enough memory "
  75                      "for spudec_CreateThread() to create the new thread" );
  76         return( 0 );
  77     }
  78
  79     /*
  80      * Initialize the thread properties
  81      */
  82     p_spudec->p_config = p_config;
  83     p_spudec->p_fifo = p_config->decoder_config.p_decoder_fifo;
  84
  85     /* Get the video output informations */
  86     p_spudec->p_vout = p_config->p_vout;
  87
  88     /* Spawn the spu decoder thread */
  89     if ( vlc_thread_create(&p_spudec->thread_id, "spu decoder",
  90          (vlc_thread_func_t)RunThread, (void *)p_spudec) )
  91     {
  92         intf_ErrMsg( "spudec error: can't spawn spu decoder thread" );
  93         free( p_spudec );
  94         return( 0 );
  95     }
  96
  97     return( p_spudec->thread_id );
  98 }
  99
 100 /* following functions are local */
 101
 102 /*****************************************************************************
 103  * InitThread: initialize spu decoder thread
 104  *****************************************************************************
 105  * This function is called from RunThread and performs the second step of the
 106  * initialization. It returns 0 on success. Note that the thread's flag are not
 107  * modified inside this function.
 108  *****************************************************************************/
 109 static int InitThread( spudec_thread_t *p_spudec )
 110 {
 111     p_spudec->p_config->decoder_config.pf_init_bit_stream(
 112             &p_spudec->bit_stream,
 113             p_spudec->p_config->decoder_config.p_decoder_fifo );
 114
 115     /* Mark thread as running and return */
 116     return( 0 );
 117 }
 118
 119 /*****************************************************************************
 120  * RunThread: spu decoder thread
 121  *****************************************************************************
 122  * spu decoder thread. This function only returns when the thread is
 123  * terminated.
 124  *****************************************************************************/
 125 static void RunThread( spudec_thread_t *p_spudec )
 126 {
 127     intf_WarnMsg( 1, "spudec: spu decoder thread %i spawned", getpid() );
 128
 129     /*
 130      * Initialize thread and free configuration
 131      */
 132     p_spudec->p_fifo->b_error = InitThread( p_spudec );
 133
 134     /*
 135      * Main loop - it is not executed if an error occured during
 136      * initialization
 137      */
 138     while( (!p_spudec->p_fifo->b_die) && (!p_spudec->p_fifo->b_error) )
 139     {
 140         if( !SyncPacket( p_spudec ) )
 141         {
 142             ParsePacket( p_spudec );
 143         }
 144     }
 145
 146     /*
 147      * Error loop
 148      */
 149     if( p_spudec->p_fifo->b_error )
 150     {
 151         ErrorThread( p_spudec );
 152     }
 153
 154     /* End of thread */
 155     intf_WarnMsg( 1, "spudec: destroying spu decoder thread %i", getpid() );
 156     EndThread( p_spudec );
 157 }
 158
 159 /*****************************************************************************
 160  * ErrorThread: RunThread() error loop
 161  *****************************************************************************
 162  * This function is called when an error occured during thread main's loop. The
 163  * thread can still receive feed, but must be ready to terminate as soon as
 164  * possible.
 165  *****************************************************************************/
 166 static void ErrorThread( spudec_thread_t *p_spudec )
 167 {
 168     /* We take the lock, because we are going to read/write the start/end
 169      * indexes of the decoder fifo */
 170     vlc_mutex_lock( &p_spudec->p_fifo->data_lock );
 171
 172     /* Wait until a `die' order is sent */
 173     while( !p_spudec->p_fifo->b_die )
 174     {
 175         /* Trash all received PES packets */
 176         while( !DECODER_FIFO_ISEMPTY(*p_spudec->p_fifo) )
 177         {
 178             p_spudec->p_fifo->pf_delete_pes( p_spudec->p_fifo->p_packets_mgt,
 179                     DECODER_FIFO_START(*p_spudec->p_fifo) );
 180             DECODER_FIFO_INCSTART( *p_spudec->p_fifo );
 181         }
 182
 183         /* Waiting for the input thread to put new PES packets in the fifo */
 184         vlc_cond_wait( &p_spudec->p_fifo->data_wait,
 185                        &p_spudec->p_fifo->data_lock );
 186     }
 187
 188     /* We can release the lock before leaving */
 189     vlc_mutex_unlock( &p_spudec->p_fifo->data_lock );
 190 }
 191
 192 /*****************************************************************************
 193  * EndThread: thread destruction
 194  *****************************************************************************
 195  * This function is called when the thread ends after a sucessful
 196  * initialization.
 197  *****************************************************************************/
 198 static void EndThread( spudec_thread_t *p_spudec )
 199 {
 200     free( p_spudec->p_config );
 201     free( p_spudec );
 202 }
 203
 204 /*****************************************************************************
 205  * SyncPacket: get in sync with the stream
 206  *****************************************************************************
 207  * This function makes a few sanity checks and returns 0 if it looks like we
 208  * are at the beginning of a subpicture packet.
 209  *****************************************************************************/
 210 static int SyncPacket( spudec_thread_t *p_spudec )
 211 {
 212     /* Re-align the buffer on an 8-bit boundary */
 213     RealignBits( &p_spudec->bit_stream );
 214
 215     /* The total SPU packet size, often bigger than a PS packet */
 216     p_spudec->i_spu_size = GetBits( &p_spudec->bit_stream, 16 );
 217
 218     /* The RLE stuff size (remove 4 because we just read 32 bits) */
 219     p_spudec->i_rle_size = ShowBits( &p_spudec->bit_stream, 16 ) - 4;
 220
 221     /* If the values we got are a bit strange, skip packet */
 222     if( p_spudec->i_rle_size >= p_spudec->i_spu_size )
 223     {
 224         return( 1 );
 225     }
 226
 227     RemoveBits( &p_spudec->bit_stream, 16 );
 228
 229     return( 0 );
 230 }
 231
 232 /*****************************************************************************
 233  * ParsePacket: parse an SPU packet and send it to the video output
 234  *****************************************************************************
 235  * This function parses the SPU packet and, if valid, sends it to the
 236  * video output.
 237  *****************************************************************************/
 238 static void ParsePacket( spudec_thread_t *p_spudec )
 239 {
 240     subpicture_t * p_spu;
 241     u8           * p_src;
 242
 243     /* We cannot display a subpicture with no date */
 244     if( DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts == 0 )
 245     {
 246         return;
 247     }
 248
 249     /* Allocate the subpicture internal data. */
 250     p_spu = vout_CreateSubPicture( p_spudec->p_vout, DVD_SUBPICTURE,
 251                                    p_spudec->i_rle_size * 4 );
 252     /* Rationale for the "p_spudec->i_rle_size * 4": we are going to
 253      * expand the RLE stuff so that we won't need to read nibbles later
 254      * on. This will speed things up a lot. Plus, we'll only need to do
 255      * this stupid interlacing stuff once. */
 256
 257     if( p_spu == NULL )
 258     {
 259         return;
 260     }
 261
 262     /* Get display time now. If we do it later, we may miss a PTS. */
 263     p_spu->begin_date = p_spu->end_date
 264                     = DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts;
 265
 266     /* Allocate the temporary buffer we will parse */
 267     p_src = malloc( p_spudec->i_rle_size );
 268
 269     if( p_src == NULL )
 270     {
 271         intf_ErrMsg( "spudec error: could not allocate p_src" );
 272         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 273         return;
 274     }
 275
 276     /* Get RLE data */
 277     GetChunk( &p_spudec->bit_stream, p_src, p_spudec->i_rle_size );
 278
 279 #if 0
 280     /* Dump the subtitle info */
 281     intf_WarnHexDump( 0, p_spu->p_data, p_spudec->i_rle_size );
 282 #endif
 283
 284     /* Getting the control part */
 285     if( ParseControlSequences( p_spudec, p_spu ) )
 286     {
 287         /* There was a parse error, delete the subpicture */
 288         free( p_src );
 289         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 290         return;
 291     }
 292
 293     if( ParseRLE( p_src, p_spu ) )
 294     {
 295         /* There was a parse error, delete the subpicture */
 296         free( p_src );
 297         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 298         return;
 299     }
 300
 301     intf_WarnMsg( 1, "spudec: got a valid %ix%i subtitle at (%i,%i), "
 302                      "RLE offsets: 0x%x 0x%x",
 303                   p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y,
 304                   p_spu->type.spu.i_offset[0], p_spu->type.spu.i_offset[1] );
 305
 306     /* SPU is finished - we can ask the video output to display it */
 307     vout_DisplaySubPicture( p_spudec->p_vout, p_spu );
 308
 309     /* Clean up */
 310     free( p_src );
 311 }
 312
 313 /*****************************************************************************
 314  * ParseControlSequences: parse all SPU control sequences
 315  *****************************************************************************
 316  * This is the most important part in SPU decoding. We get dates, palette
 317  * information, coordinates, and so on. For more information on the
 318  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 319  *****************************************************************************/
 320 static int ParseControlSequences( spudec_thread_t *p_spudec,
 321                                   subpicture_t * p_spu )
 322 {
 323     /* Our current index in the SPU packet */
 324     int i_index = p_spudec->i_rle_size + 4;
 325
 326     /* The next start-of-control-sequence index and the previous one */
 327     int i_next_index = 0, i_prev_index;
 328
 329     /* Command time and date */
 330     u8  i_command;
 331     int i_date;
 332
 333     do
 334     {
 335         /* Get the control sequence date */
 336         i_date = GetBits( &p_spudec->bit_stream, 16 );
 337
 338         /* Next offset */
 339         i_prev_index = i_next_index;
 340         i_next_index = GetBits( &p_spudec->bit_stream, 16 );
 341
 342         /* Skip what we just read */
 343         i_index += 4;
 344
 345         do
 346         {
 347             i_command = GetBits( &p_spudec->bit_stream, 8 );
 348             i_index++;
 349
 350             switch( i_command )
 351             {
 352                 case SPU_CMD_FORCE_DISPLAY:
 353
 354                     /* 00 (force displaying) */
 355                     break;
 356
 357                 /* Convert the dates in seconds to PTS values */
 358                 case SPU_CMD_START_DISPLAY:
 359
 360                     /* 01 (start displaying) */
 361                     p_spu->begin_date += ( i_date * 11000 );
 362
 363                     break;
 364
 365                 case SPU_CMD_STOP_DISPLAY:
 366
 367                     /* 02 (stop displaying) */
 368                     p_spu->end_date += ( i_date * 11000 );
 369
 370                     break;
 371
 372                 case SPU_CMD_SET_PALETTE:
 373
 374                     /* 03xxxx (palette) - trashed */
 375                     RemoveBits( &p_spudec->bit_stream, 16 );
 376                     i_index += 2;
 377
 378                     break;
 379
 380                 case SPU_CMD_SET_ALPHACHANNEL:
 381
 382                     /* 04xxxx (alpha channel) - trashed */
 383                     RemoveBits( &p_spudec->bit_stream, 16 );
 384                     i_index += 2;
 385
 386                     break;
 387
 388                 case SPU_CMD_SET_COORDINATES:
 389
 390                     /* 05xxxyyyxxxyyy (coordinates) */
 391                     p_spu->i_x = GetBits( &p_spudec->bit_stream, 12 );
 392                     p_spu->i_width = GetBits( &p_spudec->bit_stream, 12 )
 393                                       - p_spu->i_x + 1;
 394
 395                     p_spu->i_y = GetBits( &p_spudec->bit_stream, 12 );
 396                     p_spu->i_height = GetBits( &p_spudec->bit_stream, 12 )
 397                                        - p_spu->i_y + 1;
 398
 399                     i_index += 6;
 400
 401                     break;
 402
 403                 case SPU_CMD_SET_OFFSETS:
 404
 405                     /* 06xxxxyyyy (byte offsets) */
 406                     p_spu->type.spu.i_offset[0] =
 407                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 408
 409                     p_spu->type.spu.i_offset[1] =
 410                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 411
 412                     i_index += 4;
 413
 414                     break;
 415
 416                 case SPU_CMD_END:
 417
 418                     /* ff (end) */
 419                     break;
 420
 421                 default:
 422
 423                     /* xx (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, we usually "
 467                              "get 1 or none",
 468                           p_spudec->i_spu_size - i_index );
 469
 470             while( i_index < p_spudec->i_spu_size )
 471             {
 472                 RemoveBits( &p_spudec->bit_stream, 8 );
 473                 i_index++;
 474             }
 475
 476             break;
 477     }
 478
 479     /* Successfully parsed ! */
 480     return( 0 );
 481 }
 482
 483 /*****************************************************************************
 484  * ParseRLE: parse the RLE part of the subtitle
 485  *****************************************************************************
 486  * This part parses the subtitle graphical data and stores it in a more
 487  * convenient structure for later decoding. For more information on the
 488  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 489  *****************************************************************************/
 490 static int ParseRLE( u8 *p_src, subpicture_t * p_spu )
 491 {
 492     unsigned int i_code;
 493     unsigned int i_id = 0;
 494
 495     unsigned int i_width = p_spu->i_width;
 496     unsigned int i_height = p_spu->i_height;
 497     unsigned int i_x, i_y;
 498
 499     u16 *p_dest = (u16 *)p_spu->p_data;
 500
 501     /* The subtitles are interlaced, we need two offsets */
 502     unsigned int  pi_table[ 2 ];
 503     unsigned int *pi_offset;
 504
 505     pi_table[ 0 ] = p_spu->type.spu.i_offset[ 0 ] << 1;
 506     pi_table[ 1 ] = p_spu->type.spu.i_offset[ 1 ] << 1;
 507
 508     for( i_y = 0 ; i_y < i_height ; i_y++ )
 509     {
 510         pi_offset = pi_table + i_id;
 511
 512         for( i_x = 0 ; i_x < i_width ; i_x += i_code >> 2 )
 513         {
 514             i_code = AddNibble( 0, p_src, pi_offset );
 515
 516             if( i_code < 0x04 )
 517             {
 518                 i_code = AddNibble( i_code, p_src, pi_offset );
 519
 520                 if( i_code < 0x10 )
 521                 {
 522                     i_code = AddNibble( i_code, p_src, pi_offset );
 523
 524                     if( i_code < 0x040 )
 525                     {
 526                         i_code = AddNibble( i_code, p_src, pi_offset );
 527
 528                         if( i_code < 0x0100 )
 529                         {
 530                             /* If the 14 first bits are set to 0, then it's a
 531                              * new line. We emulate it. */
 532                             if( i_code < 0x0004 )
 533                             {
 534                                 i_code |= ( i_width - i_x ) << 2;
 535                             }
 536                             else
 537                             {
 538                                 /* We have a boo boo ! */
 539                                 intf_ErrMsg( "spudec error: unknown RLE code "
 540                                              "0x%.4x", i_code );
 541                                 return( 1 );
 542                             }
 543                         }
 544                     }
 545                 }
 546             }
 547
 548             if( ( (i_code >> 2) + i_x + i_y * i_width ) > i_height * i_width )
 549             {
 550                 intf_ErrMsg( "spudec error: out of bounds, %i at (%i,%i) is "
 551                              "out of %ix%i",
 552                              i_code >> 2, i_x, i_y, i_width, i_height);
 553                 return( 1 );
 554             }
 555
 556             /* We got a valid code, store it */
 557             *p_dest++ = i_code;
 558         }
 559
 560         /* Check that we didn't go too far */
 561         if( i_x > i_width )
 562         {
 563             intf_ErrMsg( "spudec error: i_x overflowed, %i > %i",
 564                          i_x, i_width );
 565             return( 1 );
 566         }
 567
 568         /* Byte-align the stream */
 569         if( *pi_offset & 0x1 )
 570         {
 571             (*pi_offset)++;
 572         }
 573
 574         /* Swap fields */
 575         i_id = ~i_id & 0x1;
 576     }
 577
 578     /* FIXME: we shouldn't need these padding bytes */
 579     while( i_y < i_height )
 580     {
 581         *p_dest++ = i_width << 2;
 582         i_y++;
 583     }
 584
 585     return( 0 );
 586 }
 587