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  ParseRLE             ( spudec_thread_t *, subpicture_t * );
  57 static int  ParseControlSequences( spudec_thread_t *, 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 */
 216     p_spudec->i_rle_size = GetBits( &p_spudec->bit_stream, 16 );
 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
 237     /* Allocate the subpicture internal data. */
 238     p_spu = vout_CreateSubPicture( p_spudec->p_vout, DVD_SUBPICTURE,
 239                                    p_spudec->i_rle_size );
 240
 241     if( p_spu == NULL )
 242     {
 243         return;
 244     }
 245
 246     /* Get display time */
 247     p_spu->begin_date = p_spu->end_date
 248                     = DECODER_FIFO_START(*p_spudec->p_fifo)->i_pts;
 249
 250     if( ParseRLE( p_spudec, p_spu ) )
 251     {
 252         /* There was a parse error, delete the subpicture */
 253         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 254         return;
 255     }
 256
 257     /* Dump the subtitle info */
 258     intf_WarnHexDump( 0, p_spu->p_data, p_spudec->i_rle_size - 4 );
 259
 260     /* Getting the control part */
 261     if( ParseControlSequences( p_spudec, p_spu ) )
 262     {
 263         /* There was a parse error, delete the subpicture */
 264         vout_DestroySubPicture( p_spudec->p_vout, p_spu );
 265         return;
 266     }
 267
 268     intf_WarnMsg( 1, "spudec: got a valid %ix%i subtitle at (%i,%i), "
 269                      "RLE offsets: 0x%x 0x%x",
 270                   p_spu->i_width, p_spu->i_height, p_spu->i_x, p_spu->i_y,
 271                   p_spu->type.spu.i_offset[0], p_spu->type.spu.i_offset[1] );
 272
 273     /* SPU is finished - we can tell the video output to display it */
 274     vout_DisplaySubPicture( p_spudec->p_vout, p_spu );
 275 }
 276
 277 /*****************************************************************************
 278  * ParseRLE: parse the RLE part of the subtitle
 279  *****************************************************************************
 280  * This part parses the subtitle graphical data and stores it in a more
 281  * convenient structure for later decoding. For more information on the
 282  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 283  * TODO: pre-parse the RLE stuff here.
 284  *****************************************************************************/
 285 static int ParseRLE( spudec_thread_t *p_spudec, subpicture_t * p_spu )
 286 {
 287     /* Get RLE data, skip 4 bytes for the first two read offsets */
 288     GetChunk( &p_spudec->bit_stream, p_spu->p_data, p_spudec->i_rle_size - 4 );
 289
 290     if( p_spudec->p_fifo->b_die )
 291     {
 292         return( 1 );
 293     }
 294
 295     return( 0 );
 296 }
 297
 298  /*****************************************************************************
 299  * ParseControlSequences: parse all SPU control sequences
 300  *****************************************************************************
 301  * This is the most important part in SPU decoding. We get dates, palette
 302  * information, coordinates, and so on. For more information on the
 303  * subtitles format, see http://sam.zoy.org/doc/dvd/subtitles/index.html
 304  *****************************************************************************/
 305 static int ParseControlSequences( spudec_thread_t *p_spudec,
 306                                   subpicture_t * p_spu )
 307 {
 308     int i_index = p_spudec->i_rle_size;
 309     int i_next_index = 0, i_prev_index;
 310
 311     int i_date;
 312     u8  i_command;
 313
 314     do
 315     {
 316         /* Get the control sequence date */
 317         i_date = GetBits( &p_spudec->bit_stream, 16 );
 318
 319         /* Next offset */
 320         i_prev_index = i_next_index;
 321         i_next_index = GetBits( &p_spudec->bit_stream, 16 );
 322
 323         /* Current offset */
 324         i_index += 4;
 325
 326         do
 327         {
 328             i_command = GetBits( &p_spudec->bit_stream, 8 );
 329             i_index++;
 330
 331             switch( i_command )
 332             {
 333                 case SPU_CMD_FORCE_DISPLAY:
 334
 335                     /* 00 (force displaying) */
 336
 337                     break;
 338
 339                 /* FIXME: here we have to calculate dates. It's around
 340                  * i_date * 12000 but I don't know how much exactly. */
 341                 case SPU_CMD_START_DISPLAY:
 342
 343                     /* 01 (start displaying) */
 344                     p_spu->begin_date += ( i_date * 12000 );
 345
 346                     break;
 347
 348                 case SPU_CMD_STOP_DISPLAY:
 349
 350                     /* 02 (stop displaying) */
 351                     p_spu->end_date += ( i_date * 12000 );
 352
 353                     break;
 354
 355                 case SPU_CMD_SET_PALETTE:
 356
 357                     /* 03xxxx (palette) - trashed */
 358                     RemoveBits( &p_spudec->bit_stream, 16 );
 359                     i_index += 2;
 360
 361                     break;
 362
 363                 case SPU_CMD_SET_ALPHACHANNEL:
 364
 365                     /* 04xxxx (alpha channel) - trashed */
 366                     RemoveBits( &p_spudec->bit_stream, 16 );
 367                     i_index += 2;
 368
 369                     break;
 370
 371                 case SPU_CMD_SET_COORDINATES:
 372
 373                     /* 05xxxyyyxxxyyy (coordinates) */
 374                     p_spu->i_x = GetBits( &p_spudec->bit_stream, 12 );
 375                     p_spu->i_width = GetBits( &p_spudec->bit_stream, 12 )
 376                                       - p_spu->i_x + 1;
 377
 378                     p_spu->i_y = GetBits( &p_spudec->bit_stream, 12 );
 379                     p_spu->i_height = GetBits( &p_spudec->bit_stream, 12 )
 380                                        - p_spu->i_y + 1;
 381
 382                     i_index += 6;
 383
 384                     break;
 385
 386                 case SPU_CMD_SET_OFFSETS:
 387
 388                     /* 06xxxxyyyy (byte offsets) */
 389                     p_spu->type.spu.i_offset[0] =
 390                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 391
 392                     p_spu->type.spu.i_offset[1] =
 393                         GetBits( &p_spudec->bit_stream, 16 ) - 4;
 394
 395                     i_index += 4;
 396
 397                     break;
 398
 399                 case SPU_CMD_END:
 400
 401                     /* ff (end) */
 402
 403                     break;
 404
 405                 default:
 406
 407                     /* ?? (unknown command) */
 408                     intf_ErrMsg( "spudec error: unknown command 0x%.2x",
 409                                  i_command );
 410                     return( 1 );
 411             }
 412
 413         } while( i_command != SPU_CMD_END );
 414
 415     } while( i_index == i_next_index );
 416
 417     /* Check that the last index matches the previous one */
 418     if( i_next_index != i_prev_index )
 419     {
 420         intf_ErrMsg( "spudec error: index mismatch (0x%.4x != 0x%.4x)",
 421                      i_next_index, i_prev_index );
 422         return( 1 );
 423     }
 424
 425     if( i_index > p_spudec->i_spu_size )
 426     {
 427         intf_ErrMsg( "spudec error: uh-oh, we went too far (0x%.4x > 0x%.4x)",
 428                      i_index, p_spudec->i_spu_size );
 429         return( 1 );
 430     }
 431
 432     /* Get rid of padding bytes */
 433     switch( p_spudec->i_spu_size - i_index )
 434     {
 435         case 1:
 436
 437             RemoveBits( &p_spudec->bit_stream, 8 );
 438             i_index++;
 439
 440         case 0:
 441
 442             /* Zero or one padding byte, quite usual */
 443
 444             break;
 445
 446         default:
 447
 448             /* More than one padding byte - this is very strange, but
 449              * we can deal with it */
 450             intf_WarnMsg( 2, "spudec warning: %i padding bytes",
 451                           p_spudec->i_spu_size - i_index );
 452
 453             while( i_index < p_spudec->i_spu_size )
 454             {
 455                 RemoveBits( &p_spudec->bit_stream, 8 );
 456                 i_index++;
 457             }
 458
 459             break;
 460     }
 461
 462     /* Successfully parsed ! */
 463     return( 0 );
 464 }
 465