git.sesse.net Git - vlc/blob - modules/codec/mpeg_video/headers.c

   1 /*****************************************************************************
   2  * vpar_headers.c : headers parsing
   3  *****************************************************************************
   4  * Copyright (C) 1999-2001 VideoLAN
   5  * $Id: headers.c,v 1.9 2003/01/30 02:16:09 gbazin Exp $
   6  *
   7  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   8  *          Stéphane Borel <stef@via.ecp.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #include <stdlib.h>                                                /* free() */
  29 #include <string.h>                                    /* memcpy(), memset() */
  30
  31 #include <vlc/vlc.h>
  32 #include <vlc/vout.h>
  33 #include <vlc/decoder.h>
  34
  35 #include "plugins.h"
  36 #include "decoder.h"
  37 #include "pool.h"
  38 #include "parser.h"
  39
  40 /*
  41  * Local prototypes
  42  */
  43 static inline void NextStartCode( bit_stream_t * );
  44 static void SequenceHeader( vpar_thread_t * p_vpar );
  45 static void GroupHeader( vpar_thread_t * p_vpar );
  46 static void PictureHeader( vpar_thread_t * p_vpar );
  47 static void ExtensionAndUserData( vpar_thread_t * p_vpar );
  48 static void QuantMatrixExtension( vpar_thread_t * p_vpar );
  49 static void SequenceScalableExtension( vpar_thread_t * p_vpar );
  50 static void SequenceDisplayExtension( vpar_thread_t * p_vpar );
  51 static void PictureDisplayExtension( vpar_thread_t * p_vpar );
  52 static void PictureSpatialScalableExtension( vpar_thread_t * p_vpar );
  53 static void PictureTemporalScalableExtension( vpar_thread_t * p_vpar );
  54 static void CopyrightExtension( vpar_thread_t * p_vpar );
  55
  56 /*
  57  * Standard variables
  58  */
  59
  60 /*****************************************************************************
  61  * pi_default_intra_quant : default quantization matrix
  62  *****************************************************************************/
  63 u8 pi_default_intra_quant[] ATTR_ALIGN(16) =
  64 {
  65     8,  16, 19, 22, 26, 27, 29, 34,
  66     16, 16, 22, 24, 27, 29, 34, 37,
  67     19, 22, 26, 27, 29, 34, 34, 38,
  68     22, 22, 26, 27, 29, 34, 37, 40,
  69     22, 26, 27, 29, 32, 35, 40, 48,
  70     26, 27, 29, 32, 35, 40, 48, 58,
  71     26, 27, 29, 34, 38, 46, 56, 69,
  72     27, 29, 35, 38, 46, 56, 69, 83
  73 };
  74
  75 /*****************************************************************************
  76  * pi_default_nonintra_quant : default quantization matrix
  77  *****************************************************************************/
  78 u8 pi_default_nonintra_quant[] ATTR_ALIGN(16) =
  79 {
  80     16, 16, 16, 16, 16, 16, 16, 16,
  81     16, 16, 16, 16, 16, 16, 16, 16,
  82     16, 16, 16, 16, 16, 16, 16, 16,
  83     16, 16, 16, 16, 16, 16, 16, 16,
  84     16, 16, 16, 16, 16, 16, 16, 16,
  85     16, 16, 16, 16, 16, 16, 16, 16,
  86     16, 16, 16, 16, 16, 16, 16, 16,
  87     16, 16, 16, 16, 16, 16, 16, 16
  88 };
  89
  90 /*****************************************************************************
  91  * pi_scan : zig-zag and alternate scan patterns
  92  *****************************************************************************/
  93 u8 pi_scan[2][64] ATTR_ALIGN(16) =
  94 {
  95     { /* Zig-Zag pattern */
  96         0,1,8,16,9,2,3,10,17,24,32,25,18,11,4,5,
  97         12,19,26,33,40,48,41,34,27,20,13,6,7,14,21,28,
  98         35,42,49,56,57,50,43,36,29,22,15,23,30,37,44,51,
  99         58,59,52,45,38,31,39,46,53,60,61,54,47,55,62,63
 100     },
 101     { /* Alternate scan pattern */
 102         0,8,16,24,1,9,2,10,17,25,32,40,48,56,57,49,
 103         41,33,26,18,3,11,4,12,19,27,34,42,50,58,35,43,
 104         51,59,20,28,5,13,6,14,21,29,36,44,52,60,37,45,
 105         53,61,22,30,7,15,23,31,38,46,54,62,39,47,55,63
 106     }
 107 };
 108
 109 /*
 110  * Local inline functions.
 111  */
 112
 113 /*****************************************************************************
 114  * ReferenceUpdate : Update the reference pointers when we have a new picture
 115  *****************************************************************************/
 116 static void inline ReferenceUpdate( vpar_thread_t * p_vpar,
 117                                     int i_coding_type, picture_t * p_newref )
 118 {
 119     if( i_coding_type != B_CODING_TYPE )
 120     {
 121         if( p_vpar->sequence.p_forward != NULL )
 122         {
 123             vout_UnlinkPicture( p_vpar->p_vout, p_vpar->sequence.p_forward );
 124         }
 125         if( p_vpar->sequence.p_backward != NULL )
 126         {
 127             vout_DatePicture( p_vpar->p_vout, p_vpar->sequence.p_backward,
 128                               vpar_SynchroDate( p_vpar ) );
 129         }
 130         p_vpar->sequence.p_forward = p_vpar->sequence.p_backward;
 131         p_vpar->sequence.p_backward = p_newref;
 132         if( p_newref != NULL )
 133         {
 134             vout_LinkPicture( p_vpar->p_vout, p_newref );
 135         }
 136     }
 137     else if( p_newref != NULL )
 138     {
 139         /* Put date immediately. */
 140         vout_DatePicture( p_vpar->p_vout, p_newref, vpar_SynchroDate(p_vpar) );
 141     }
 142 }
 143
 144 /*****************************************************************************
 145  * ReferenceReplace : Replace the last reference pointer when we destroy
 146  *                    a picture
 147  *****************************************************************************/
 148 static void inline ReferenceReplace( vpar_thread_t * p_vpar,
 149                                      int i_coding_type, picture_t * p_newref )
 150 {
 151     if( i_coding_type != B_CODING_TYPE )
 152     {
 153         if( p_vpar->sequence.p_backward != NULL )
 154         {
 155             vout_UnlinkPicture( p_vpar->p_vout, p_vpar->sequence.p_backward );
 156         }
 157         p_vpar->sequence.p_backward = p_newref;
 158         if( p_newref != NULL )
 159         {
 160             vout_LinkPicture( p_vpar->p_vout, p_newref );
 161         }
 162     }
 163 }
 164
 165 /*****************************************************************************
 166  * LoadMatrix : Load a quantization matrix
 167  *****************************************************************************/
 168 static inline void LoadMatrix( vpar_thread_t * p_vpar,
 169                                quant_matrix_t * p_matrix )
 170 {
 171     int i_dummy;
 172
 173     if( !p_matrix->b_allocated )
 174     {
 175         /* Allocate a piece of memory to load the matrix. */
 176         if( (p_matrix->pi_matrix = (u8 *)malloc( 64*sizeof(u8) )) == NULL )
 177         {
 178             msg_Err( p_vpar->p_fifo, "out of memory" );
 179             p_vpar->p_fifo->b_error = 1;
 180             return;
 181         }
 182         p_matrix->b_allocated = 1;
 183     }
 184
 185     for( i_dummy = 0; i_dummy < 64; i_dummy++ )
 186     {
 187         p_matrix->pi_matrix[p_vpar->ppi_scan[0][i_dummy]]
 188              = GetBits( &p_vpar->bit_stream, 8 );
 189     }
 190 }
 191
 192 /*****************************************************************************
 193  * LinkMatrix : Link a quantization matrix to another
 194  *****************************************************************************/
 195 static inline void LinkMatrix( quant_matrix_t * p_matrix, u8 * pi_array )
 196 {
 197     if( p_matrix->b_allocated )
 198     {
 199         /* Deallocate the piece of memory. */
 200         free( p_matrix->pi_matrix );
 201         p_matrix->b_allocated = 0;
 202     }
 203
 204     p_matrix->pi_matrix = pi_array;
 205 }
 206
 207 /*****************************************************************************
 208  * ChromaToFourCC: Return a FourCC value used by the video output.
 209  *****************************************************************************/
 210 static inline vlc_fourcc_t ChromaToFourCC( int i_chroma )
 211 {
 212     switch( i_chroma )
 213     {
 214         case CHROMA_420:
 215             return VLC_FOURCC('I','4','2','0');
 216
 217         case CHROMA_422:
 218             return VLC_FOURCC('I','4','2','2');
 219
 220         case CHROMA_444:
 221             return VLC_FOURCC('I','4','4','4');
 222
 223         default:
 224             /* This can't happen */
 225             return 0xdeadbeef;
 226     }
 227 }
 228
 229 /*
 230  * Exported functions.
 231  */
 232
 233 /*****************************************************************************
 234  * vpar_NextSequenceHeader : Find the next sequence header
 235  *****************************************************************************/
 236 int vpar_NextSequenceHeader( vpar_thread_t * p_vpar )
 237 {
 238     while( !p_vpar->p_fifo->b_die )
 239     {
 240         NextStartCode( &p_vpar->bit_stream );
 241         if( ShowBits( &p_vpar->bit_stream, 32 ) == SEQUENCE_HEADER_CODE )
 242         {
 243             return 0;
 244         }
 245         RemoveBits( &p_vpar->bit_stream, 8 );
 246     }
 247     return 1;
 248 }
 249
 250 /*****************************************************************************
 251  * vpar_ParseHeader : Parse the next header
 252  *****************************************************************************/
 253 int vpar_ParseHeader( vpar_thread_t * p_vpar )
 254 {
 255     NextStartCode( &p_vpar->bit_stream );
 256     switch( GetBits32( &p_vpar->bit_stream ) )
 257     {
 258     case SEQUENCE_HEADER_CODE:
 259         p_vpar->c_sequences++;
 260         SequenceHeader( p_vpar );
 261         return 0;
 262
 263     case GROUP_START_CODE:
 264         GroupHeader( p_vpar );
 265         return 0;
 266
 267     case PICTURE_START_CODE:
 268         PictureHeader( p_vpar );
 269         return 0;
 270
 271     case SEQUENCE_END_CODE:
 272         msg_Dbg( p_vpar->p_fifo, "sequence end code received" );
 273         if( p_vpar->sequence.p_backward != NULL )
 274         {
 275             p_vpar->sequence.p_backward->b_force = 1;
 276         }
 277         ReferenceUpdate( p_vpar, I_CODING_TYPE, NULL );
 278         return 1;
 279
 280     default:
 281         break;
 282     }
 283
 284     return 0;
 285 }
 286
 287 /*
 288  * Following functions are local
 289  */
 290
 291 /*****************************************************************************
 292  * SequenceHeader : Parse the next sequence header
 293  *****************************************************************************/
 294 static void SequenceHeader( vpar_thread_t * p_vpar )
 295 {
 296 #define RESERVED    -1
 297     static int i_frame_rate_table[16] =
 298     {
 299         0,
 300         23 * 1000,
 301         24 * 1001,
 302         25 * 1001,
 303         30 * 1000,
 304         30 * 1001,
 305         50 * 1001,
 306         60 * 1000,
 307         60 * 1001,
 308         RESERVED, RESERVED, RESERVED, RESERVED, RESERVED, RESERVED, RESERVED
 309     };
 310 #undef RESERVED
 311
 312     int i_aspect;
 313
 314     p_vpar->sequence.i_width = GetBits( &p_vpar->bit_stream, 12 );
 315     p_vpar->sequence.i_height = GetBits( &p_vpar->bit_stream, 12 );
 316     i_aspect = GetBits( &p_vpar->bit_stream, 4 );
 317     p_vpar->sequence.i_frame_rate =
 318             i_frame_rate_table[ GetBits( &p_vpar->bit_stream, 4 ) ];
 319
 320     /* We don't need bit_rate_value, marker_bit, vbv_buffer_size,
 321      * constrained_parameters_flag */
 322     RemoveBits( &p_vpar->bit_stream, 30 );
 323
 324     /*
 325      * Quantization matrices
 326      */
 327     if( GetBits( &p_vpar->bit_stream, 1 ) ) /* load_intra_quantizer_matrix */
 328     {
 329         LoadMatrix( p_vpar, &p_vpar->sequence.intra_quant );
 330     }
 331     else
 332     {
 333         /* Use default matrix. */
 334         LinkMatrix( &p_vpar->sequence.intra_quant,
 335                     p_vpar->pi_default_intra_quant );
 336     }
 337
 338     if( GetBits(&p_vpar->bit_stream, 1) ) /* load_non_intra_quantizer_matrix */
 339     {
 340         LoadMatrix( p_vpar, &p_vpar->sequence.nonintra_quant );
 341     }
 342     else
 343     {
 344         /* Use default matrix. */
 345         LinkMatrix( &p_vpar->sequence.nonintra_quant,
 346                     p_vpar->pi_default_nonintra_quant );
 347     }
 348
 349     /* Unless later overwritten by a matrix extension, we have the same
 350      * matrices for luminance and chrominance. */
 351     LinkMatrix( &p_vpar->sequence.chroma_intra_quant,
 352                 p_vpar->sequence.intra_quant.pi_matrix );
 353     LinkMatrix( &p_vpar->sequence.chroma_nonintra_quant,
 354                 p_vpar->sequence.nonintra_quant.pi_matrix );
 355
 356     /*
 357      * Sequence Extension
 358      */
 359     NextStartCode( &p_vpar->bit_stream );
 360     if( ShowBits( &p_vpar->bit_stream, 32 ) == EXTENSION_START_CODE )
 361     {
 362         int                         i_dummy;
 363
 364         /* Turn the MPEG2 flag on */
 365         p_vpar->sequence.b_mpeg2 = 1;
 366
 367         /* Parse sequence_extension */
 368         RemoveBits32( &p_vpar->bit_stream );
 369         /* extension_start_code_identifier, profile_and_level_indication */
 370         RemoveBits( &p_vpar->bit_stream, 12 );
 371         p_vpar->sequence.b_progressive = GetBits( &p_vpar->bit_stream, 1 );
 372         p_vpar->sequence.i_chroma_format = GetBits( &p_vpar->bit_stream, 2 );
 373         p_vpar->sequence.i_width |= GetBits( &p_vpar->bit_stream, 2 ) << 12;
 374         p_vpar->sequence.i_height |= GetBits( &p_vpar->bit_stream, 2 ) << 12;
 375         /* bit_rate_extension, marker_bit, vbv_buffer_size_extension,
 376          * low_delay */
 377         RemoveBits( &p_vpar->bit_stream, 22 );
 378         /* frame_rate_extension_n */
 379         i_dummy = GetBits( &p_vpar->bit_stream, 2 );
 380         /* frame_rate_extension_d */
 381         p_vpar->sequence.i_frame_rate *= (i_dummy + 1)
 382                                   / (GetBits( &p_vpar->bit_stream, 5 ) + 1);
 383     }
 384     else
 385     {
 386         /* It's an MPEG-1 stream. Put adequate parameters. */
 387         int i_xyratio;
 388         static int pi_mpeg1ratio[15] = {
 389             10000, 10000,  6735,  7031,  7615,  8055,  8437, 8935,
 390              9157,  9815, 10255, 10695, 10950, 11575, 12015
 391         };
 392
 393         if( i_aspect > 1 )
 394         {
 395                 i_xyratio = p_vpar->sequence.i_height *
 396                         pi_mpeg1ratio[i_aspect] / p_vpar->sequence.i_width;
 397                 if( 7450 < i_xyratio && i_xyratio < 7550 )
 398                 {
 399                         i_aspect = 2;
 400                 }
 401                 else if( 5575 < i_xyratio && i_xyratio < 5675 )
 402                 {
 403                         i_aspect = 3;
 404                 }
 405                 else if( 4475 < i_xyratio && i_xyratio < 4575 )
 406                 {
 407                         i_aspect = 4;
 408                 }
 409         }
 410
 411         p_vpar->sequence.b_mpeg2 = 0;
 412         p_vpar->sequence.b_progressive = 1;
 413         p_vpar->sequence.i_chroma_format = CHROMA_420;
 414     }
 415
 416     /* check whether the input gives a particular aspect ratio */
 417     if( p_vpar->p_fifo->p_demux_data
 418          && ( *(int*)(p_vpar->p_fifo->p_demux_data) & 0x7 ) )
 419     {
 420         i_aspect = *(int*)(p_vpar->p_fifo->p_demux_data);
 421     }
 422
 423     /* Store calculated aspect ratio */
 424     switch( i_aspect )
 425     {
 426         case AR_3_4_PICTURE:
 427             p_vpar->sequence.i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 428             break;
 429
 430         case AR_16_9_PICTURE:
 431             p_vpar->sequence.i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 432             break;
 433
 434         case AR_221_1_PICTURE:
 435             p_vpar->sequence.i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 436             break;
 437
 438         case AR_SQUARE_PICTURE:
 439         default:
 440             p_vpar->sequence.i_aspect = VOUT_ASPECT_FACTOR
 441                     * p_vpar->sequence.i_width / p_vpar->sequence.i_height;
 442             break;
 443     }
 444
 445     /* Update sizes */
 446     p_vpar->sequence.i_mb_width = (p_vpar->sequence.i_width + 15) / 16;
 447     p_vpar->sequence.i_mb_height = (p_vpar->sequence.b_progressive) ?
 448                                    (p_vpar->sequence.i_height + 15) / 16 :
 449                                    2 * ((p_vpar->sequence.i_height + 31) / 32);
 450     p_vpar->sequence.i_mb_size = p_vpar->sequence.i_mb_width
 451                                         * p_vpar->sequence.i_mb_height;
 452     p_vpar->sequence.i_width = (p_vpar->sequence.i_mb_width * 16);
 453     p_vpar->sequence.i_height = (p_vpar->sequence.i_mb_height * 16);
 454     p_vpar->sequence.i_size = p_vpar->sequence.i_width
 455                                         * p_vpar->sequence.i_height;
 456     switch( p_vpar->sequence.i_chroma_format )
 457     {
 458     case CHROMA_420:
 459         p_vpar->sequence.i_chroma_nb_blocks = 2;
 460         p_vpar->sequence.b_chroma_h_subsampled = 1;
 461         p_vpar->sequence.b_chroma_v_subsampled = 1;
 462         break;
 463     case CHROMA_422:
 464         p_vpar->sequence.i_chroma_nb_blocks = 4;
 465         p_vpar->sequence.b_chroma_h_subsampled = 1;
 466         p_vpar->sequence.b_chroma_v_subsampled = 0;
 467         break;
 468     case CHROMA_444:
 469         p_vpar->sequence.i_chroma_nb_blocks = 6;
 470         p_vpar->sequence.b_chroma_h_subsampled = 0;
 471         p_vpar->sequence.b_chroma_v_subsampled = 0;
 472         break;
 473     }
 474
 475     /* Extension and User data */
 476     ExtensionAndUserData( p_vpar );
 477
 478     /* Spawn a video output if there is none. First we look for our children,
 479      * then we look for any other vout that might be available. */
 480     p_vpar->p_vout =
 481            vout_Request( p_vpar->p_fifo, p_vpar->p_vout,
 482                          p_vpar->sequence.i_width, p_vpar->sequence.i_height,
 483                          ChromaToFourCC( p_vpar->sequence.i_chroma_format ),
 484                          p_vpar->sequence.i_aspect );
 485
 486     if( p_vpar->p_fifo->b_die || p_vpar->p_fifo->b_error )
 487     {
 488         return;
 489     }
 490
 491     if( p_vpar->p_vout == NULL )
 492     {
 493         msg_Err( p_vpar->p_fifo, "cannot open vout, aborting" );
 494         p_vpar->p_fifo->b_error = 1;
 495         return;
 496     }
 497 }
 498
 499 /*****************************************************************************
 500  * GroupHeader : Parse the next group of pictures header
 501  *****************************************************************************/
 502 static void GroupHeader( vpar_thread_t * p_vpar )
 503 {
 504     /* Nothing to do, we don't care. */
 505     RemoveBits( &p_vpar->bit_stream, 27 );
 506     ExtensionAndUserData( p_vpar );
 507 }
 508
 509 /*****************************************************************************
 510  * PictureHeader : Parse the next picture header
 511  *****************************************************************************/
 512 static void PictureHeader( vpar_thread_t * p_vpar )
 513 {
 514     int                 i_structure, i_previous_coding_type;
 515     vlc_bool_t          b_parsable = 0;
 516
 517     /* Retrieve the PTS. */
 518     CurrentPTS( &p_vpar->bit_stream, &p_vpar->sequence.next_pts,
 519                 &p_vpar->sequence.next_dts );
 520
 521     /* Recover in case of stream discontinuity. */
 522     if( p_vpar->sequence.b_expect_discontinuity )
 523     {
 524         ReferenceUpdate( p_vpar, I_CODING_TYPE, NULL );
 525         ReferenceUpdate( p_vpar, I_CODING_TYPE, NULL );
 526         if( p_vpar->picture.p_picture != NULL )
 527         {
 528             vout_DestroyPicture( p_vpar->p_vout, p_vpar->picture.p_picture );
 529             p_vpar->picture.p_picture = NULL;
 530         }
 531         p_vpar->picture.i_current_structure = 0;
 532         p_vpar->sequence.b_expect_discontinuity = 0;
 533     }
 534
 535     /* Parse the picture header. */
 536     RemoveBits( &p_vpar->bit_stream, 10 ); /* temporal_reference */
 537     i_previous_coding_type = p_vpar->picture.i_coding_type;
 538     p_vpar->picture.i_coding_type = GetBits( &p_vpar->bit_stream, 3 );
 539     RemoveBits( &p_vpar->bit_stream, 16 ); /* vbv_delay */
 540
 541     if( p_vpar->picture.i_coding_type == P_CODING_TYPE
 542         || p_vpar->picture.i_coding_type == B_CODING_TYPE )
 543     {
 544         p_vpar->picture.ppi_f_code[0][1] = GetBits( &p_vpar->bit_stream, 1 );
 545         p_vpar->picture.ppi_f_code[0][0] = GetBits( &p_vpar->bit_stream, 3 )
 546                                             - 1;
 547     }
 548     if( p_vpar->picture.i_coding_type == B_CODING_TYPE )
 549     {
 550         p_vpar->picture.ppi_f_code[1][1] = GetBits( &p_vpar->bit_stream, 1 );
 551         p_vpar->picture.ppi_f_code[1][0] = GetBits( &p_vpar->bit_stream, 3 )
 552                                             - 1;
 553     }
 554
 555     /* extra_information_picture */
 556     while( GetBits( &p_vpar->bit_stream, 1 ) )
 557     {
 558         RemoveBits( &p_vpar->bit_stream, 8 );
 559     }
 560
 561     /*
 562      * Picture Coding Extension
 563      */
 564     NextStartCode( &p_vpar->bit_stream );
 565     if( ShowBits( &p_vpar->bit_stream, 32 ) == EXTENSION_START_CODE )
 566     {
 567         /* Parse picture_coding_extension */
 568         RemoveBits32( &p_vpar->bit_stream );
 569         /* extension_start_code_identifier */
 570         RemoveBits( &p_vpar->bit_stream, 4 );
 571
 572         /* Pre-substract 1 for later use in MotionDelta(). */
 573         p_vpar->picture.ppi_f_code[0][0] = GetBits( &p_vpar->bit_stream, 4 ) -1;
 574         p_vpar->picture.ppi_f_code[0][1] = GetBits( &p_vpar->bit_stream, 4 ) -1;
 575         p_vpar->picture.ppi_f_code[1][0] = GetBits( &p_vpar->bit_stream, 4 ) -1;
 576         p_vpar->picture.ppi_f_code[1][1] = GetBits( &p_vpar->bit_stream, 4 ) -1;
 577         p_vpar->picture.i_intra_dc_precision = GetBits( &p_vpar->bit_stream, 2 );
 578         i_structure = GetBits( &p_vpar->bit_stream, 2 );
 579         p_vpar->picture.b_top_field_first = GetBits( &p_vpar->bit_stream, 1 );
 580         p_vpar->picture.b_frame_pred_frame_dct
 581              = GetBits( &p_vpar->bit_stream, 1 );
 582         p_vpar->picture.b_concealment_mv = GetBits( &p_vpar->bit_stream, 1 );
 583         p_vpar->picture.b_q_scale_type = GetBits( &p_vpar->bit_stream, 1 );
 584         p_vpar->picture.b_intra_vlc_format = GetBits( &p_vpar->bit_stream, 1 );
 585         /* Alternate scan */
 586         p_vpar->picture.pi_scan =
 587             p_vpar->ppi_scan[ GetBits( &p_vpar->bit_stream, 1 ) ];
 588         p_vpar->picture.b_repeat_first_field = GetBits( &p_vpar->bit_stream, 1 );
 589         /* chroma_420_type (obsolete) */
 590         RemoveBits( &p_vpar->bit_stream, 1 );
 591         p_vpar->picture.b_progressive = GetBits( &p_vpar->bit_stream, 1 );
 592
 593         /* composite_display_flag */
 594         if( GetBits( &p_vpar->bit_stream, 1 ) )
 595         {
 596             /* v_axis, field_sequence, sub_carrier, burst_amplitude,
 597              * sub_carrier_phase */
 598             RemoveBits( &p_vpar->bit_stream, 20 );
 599         }
 600     }
 601     else
 602     {
 603         /* MPEG-1 compatibility flags */
 604         p_vpar->picture.i_intra_dc_precision = 0; /* 8 bits */
 605         i_structure = FRAME_STRUCTURE;
 606         p_vpar->picture.b_top_field_first = 0;
 607         p_vpar->picture.b_frame_pred_frame_dct = 1;
 608         p_vpar->picture.b_concealment_mv = 0;
 609         p_vpar->picture.b_q_scale_type = 0;
 610         p_vpar->picture.b_intra_vlc_format = 0;
 611         p_vpar->picture.pi_scan = p_vpar->ppi_scan[0];
 612         p_vpar->picture.b_repeat_first_field = 0;
 613         p_vpar->picture.b_progressive = 1;
 614     }
 615
 616     p_vpar->picture.b_frame_structure = (i_structure == FRAME_STRUCTURE);
 617
 618     /* Extension and User data. */
 619     ExtensionAndUserData( p_vpar );
 620
 621     p_vpar->pc_pictures[p_vpar->picture.i_coding_type]++;
 622
 623     if( p_vpar->picture.i_current_structure )
 624     {
 625         if ( (i_structure == FRAME_STRUCTURE ||
 626               i_structure == p_vpar->picture.i_current_structure) )
 627         {
 628             /* We don't have the second field of the buffered frame. */
 629             if( p_vpar->picture.p_picture != NULL )
 630             {
 631                 ReferenceReplace( p_vpar,
 632                                   p_vpar->picture.i_coding_type,
 633                                   NULL );
 634                 vout_DestroyPicture( p_vpar->p_vout,
 635                                      p_vpar->picture.p_picture );
 636                 p_vpar->picture.p_picture = NULL;
 637             }
 638
 639             p_vpar->picture.i_current_structure = 0;
 640
 641             msg_Warn( p_vpar->p_fifo, "odd number of field pictures" );
 642         }
 643         else
 644         {
 645             /* Second field of a frame. We will decode it if, and only if we
 646              * have decoded the first field. */
 647             if( p_vpar->picture.p_picture == NULL )
 648             {
 649                 if( (p_vpar->picture.i_coding_type == I_CODING_TYPE
 650                       && p_vpar->sequence.p_backward == NULL) )
 651                 {
 652                     /* Exceptionnally, parse the picture if it is I. We need
 653                      * this in case of an odd number of field pictures, if the
 654                      * previous picture is not intra, we desperately need a
 655                      * new reference picture. OK, this is kind of kludgy. */
 656                     p_vpar->picture.i_current_structure = 0;
 657                 }
 658                 else
 659                 {
 660                     b_parsable = 0;
 661                 }
 662             }
 663             else
 664             {
 665                 /* We suppose we have the reference pictures, since we already
 666                  * decoded the first field and the second field will not need
 667                  * any extra reference picture. There is a special case of
 668                  * P field being the second field of an I field, but ISO/IEC
 669                  * 13818-2 section 7.6.3.5 specifies that this P field will
 670                  * not need any reference picture besides the I field. So far
 671                  * so good. */
 672                 b_parsable = 1;
 673
 674                 if( p_vpar->picture.i_coding_type == P_CODING_TYPE &&
 675                     i_previous_coding_type == I_CODING_TYPE &&
 676                     p_vpar->sequence.p_forward == NULL )
 677                 {
 678                     /* This is the special case of section 7.6.3.5. Create
 679                      * a fake reference picture (which will not be used)
 680                      * but will prevent us from segfaulting in the slice
 681                      * parsing. */
 682                     static picture_t    fake_picture;
 683                     fake_picture.i_planes = 0; /* We will use it later */
 684                     p_vpar->sequence.p_forward = &fake_picture;
 685                 }
 686             }
 687         }
 688     }
 689
 690     if( !p_vpar->picture.i_current_structure )
 691     {
 692         /* First field of a frame, or new frame picture. */
 693         int     i_repeat_field;
 694
 695         /* Do we have the reference pictures ? */
 696         b_parsable = !(((p_vpar->picture.i_coding_type == P_CODING_TYPE ||
 697                          p_vpar->picture.b_concealment_mv) &&
 698                         (p_vpar->sequence.p_backward == NULL)) ||
 699                          /* p_backward will become p_forward later */
 700                        ((p_vpar->picture.i_coding_type == B_CODING_TYPE) &&
 701                         (p_vpar->sequence.p_forward == NULL ||
 702                          p_vpar->sequence.p_backward == NULL)));
 703
 704         /* Compute the number of times the frame will be emitted by the
 705          * decoder (number of half-periods). */
 706         if( p_vpar->sequence.b_progressive )
 707         {
 708             i_repeat_field = (1 + p_vpar->picture.b_repeat_first_field
 709                                 + p_vpar->picture.b_top_field_first) * 2;
 710         }
 711         else
 712         {
 713             if( p_vpar->picture.b_progressive )
 714             {
 715                 i_repeat_field = 2 + p_vpar->picture.b_repeat_first_field;
 716             }
 717             else
 718             {
 719                 i_repeat_field = 2;
 720             }
 721         }
 722
 723         /* Warn synchro we have a new picture (updates pictures index). */
 724         vpar_SynchroNewPicture( p_vpar, p_vpar->picture.i_coding_type,
 725                                 i_repeat_field );
 726
 727         if( b_parsable )
 728         {
 729             /* Does synchro say we have enough time to decode it ? */
 730             b_parsable = vpar_SynchroChoose( p_vpar,
 731                                p_vpar->picture.i_coding_type, i_structure );
 732         }
 733     }
 734
 735     if( !b_parsable )
 736     {
 737         /* Update the reference pointers. */
 738         ReferenceUpdate( p_vpar, p_vpar->picture.i_coding_type, NULL );
 739
 740         /* Update context. */
 741         if( i_structure != FRAME_STRUCTURE )
 742         {
 743             if( (p_vpar->picture.i_current_structure | i_structure)
 744                     == FRAME_STRUCTURE )
 745             {
 746                 /* The frame is complete. */
 747                 p_vpar->picture.i_current_structure = 0;
 748
 749                 vpar_SynchroTrash( p_vpar, p_vpar->picture.i_coding_type, i_structure );
 750             }
 751             else
 752             {
 753                 p_vpar->picture.i_current_structure = i_structure;
 754             }
 755         }
 756         else
 757         {
 758             /* Warn Synchro we have trashed a picture. */
 759             vpar_SynchroTrash( p_vpar, p_vpar->picture.i_coding_type, i_structure );
 760         }
 761         p_vpar->picture.p_picture = NULL;
 762
 763         return;
 764     }
 765
 766     /* OK, now we are sure we will decode the picture. */
 767     p_vpar->pc_decoded_pictures[p_vpar->picture.i_coding_type]++;
 768
 769 #define P_picture p_vpar->picture.p_picture
 770     p_vpar->picture.b_error = 0;
 771
 772     if( !p_vpar->picture.i_current_structure )
 773     {
 774         /* This is a new frame. Get a structure from the video_output. */
 775         while( ( P_picture = vout_CreatePicture( p_vpar->p_vout,
 776                                  p_vpar->picture.b_progressive,
 777                                  p_vpar->picture.b_top_field_first,
 778                                  p_vpar->picture.b_repeat_first_field ) )
 779                  == NULL )
 780         {
 781             if( p_vpar->p_fifo->b_die || p_vpar->p_fifo->b_error )
 782             {
 783                 return;
 784             }
 785             msleep( VOUT_OUTMEM_SLEEP );
 786         }
 787
 788         /* Initialize values. */
 789         vpar_SynchroDecode( p_vpar, p_vpar->picture.i_coding_type, i_structure );
 790         P_picture->i_matrix_coefficients = p_vpar->sequence.i_matrix_coefficients;
 791
 792         /* Update the reference pointers. */
 793         ReferenceUpdate( p_vpar, p_vpar->picture.i_coding_type, P_picture );
 794     }
 795
 796     /* Initialize picture data for decoding. */
 797     p_vpar->picture.i_current_structure |= i_structure;
 798     p_vpar->picture.i_structure = i_structure;
 799     p_vpar->picture.b_second_field =
 800         (i_structure != p_vpar->picture.i_current_structure);
 801     p_vpar->picture.b_current_field =
 802         (i_structure == BOTTOM_FIELD );
 803     p_vpar->picture.i_lum_stride = p_vpar->picture.p_picture->Y_PITCH
 804         << ( 1 - p_vpar->picture.b_frame_structure );
 805     p_vpar->picture.i_chrom_stride = p_vpar->picture.p_picture->U_PITCH
 806         << ( 1 - p_vpar->picture.b_frame_structure );
 807     /* We suppose the pitch is the same for U and V planes. */
 808     p_vpar->picture.i_field_width = p_vpar->sequence.i_width
 809         << ( 1 - p_vpar->picture.b_frame_structure );
 810
 811     if( !p_vpar->p_fifo->p_stream_ctrl->b_grayscale )
 812     {
 813         switch( p_vpar->sequence.i_chroma_format )
 814         {
 815         case CHROMA_422:
 816             p_vpar->pool.pf_vdec_decode = vdec_DecodeMacroblock422;
 817             break;
 818         case CHROMA_444:
 819             p_vpar->pool.pf_vdec_decode = vdec_DecodeMacroblock444;
 820             break;
 821         case CHROMA_420:
 822         default:
 823             p_vpar->pool.pf_vdec_decode = vdec_DecodeMacroblock420;
 824             break;
 825         }
 826     }
 827     else
 828     {
 829         p_vpar->pool.pf_vdec_decode = vdec_DecodeMacroblockBW;
 830     }
 831
 832
 833     if( p_vpar->sequence.b_mpeg2 )
 834     {
 835         static f_picture_data_t ppf_picture_data[4][4] =
 836         {
 837             {
 838                 NULL, NULL, NULL, NULL
 839             },
 840             {
 841                 /* TOP_FIELD */
 842 #if (VPAR_OPTIM_LEVEL > 1)
 843                 NULL, vpar_PictureData2IT, vpar_PictureData2PT,
 844                 vpar_PictureData2BT
 845 #else
 846                 NULL, vpar_PictureDataGENERIC, vpar_PictureDataGENERIC,
 847                 vpar_PictureDataGENERIC
 848 #endif
 849             },
 850             {
 851                 /* BOTTOM_FIELD */
 852 #if (VPAR_OPTIM_LEVEL > 1)
 853                 NULL, vpar_PictureData2IB, vpar_PictureData2PB,
 854                 vpar_PictureData2BB
 855 #else
 856                 NULL, vpar_PictureDataGENERIC, vpar_PictureDataGENERIC,
 857                 vpar_PictureDataGENERIC
 858 #endif
 859             },
 860             {
 861                 /* FRAME_PICTURE */
 862 #if (VPAR_OPTIM_LEVEL > 0)
 863                 NULL, vpar_PictureData2IF, vpar_PictureData2PF,
 864                 vpar_PictureData2BF
 865 #else
 866                 NULL, vpar_PictureDataGENERIC, vpar_PictureDataGENERIC,
 867                 vpar_PictureDataGENERIC
 868 #endif
 869             }
 870         };
 871
 872         ppf_picture_data[p_vpar->picture.i_structure]
 873                         [p_vpar->picture.i_coding_type]( p_vpar );
 874     }
 875     else
 876     {
 877 #if (VPAR_OPTIM_LEVEL > 1)
 878         static f_picture_data_t pf_picture_data[5] =
 879         { NULL, vpar_PictureData1I, vpar_PictureData1P, vpar_PictureData1B,
 880           vpar_PictureData1D };
 881
 882         pf_picture_data[p_vpar->picture.i_coding_type]( p_vpar );
 883 #else
 884         vpar_PictureDataGENERIC( p_vpar );
 885 #endif
 886     }
 887
 888     /* Wait for all the macroblocks to be decoded. */
 889     p_vpar->pool.pf_wait_pool( &p_vpar->pool );
 890
 891     /* Re-spawn decoder threads if the user changed settings. */
 892     vpar_SpawnPool( p_vpar );
 893
 894     if( p_vpar->p_fifo->b_die || p_vpar->p_fifo->b_error )
 895     {
 896         return;
 897     }
 898
 899     if( p_vpar->sequence.p_forward != NULL &&
 900         p_vpar->sequence.p_forward->i_planes == 0 )
 901     {
 902         /* This can only happen with the fake picture created for section
 903          * 7.6.3.5. Clean up our mess. */
 904         p_vpar->sequence.p_forward = NULL;
 905     }
 906
 907     if( p_vpar->picture.b_error )
 908     {
 909         /* Trash picture. */
 910         p_vpar->pc_malformed_pictures[p_vpar->picture.i_coding_type]++;
 911
 912         vpar_SynchroEnd( p_vpar, p_vpar->picture.i_coding_type,
 913                          p_vpar->picture.i_structure, 1 );
 914         vout_DestroyPicture( p_vpar->p_vout, P_picture );
 915
 916         ReferenceReplace( p_vpar, p_vpar->picture.i_coding_type, NULL );
 917
 918         /* Prepare context for the next picture. */
 919         P_picture = NULL;
 920         if( p_vpar->picture.i_current_structure == FRAME_STRUCTURE )
 921             p_vpar->picture.i_current_structure = 0;
 922     }
 923     else if( p_vpar->picture.i_current_structure == FRAME_STRUCTURE )
 924     {
 925         /* Frame completely parsed. */
 926         vpar_SynchroEnd( p_vpar, p_vpar->picture.i_coding_type,
 927                          p_vpar->picture.i_structure, 0 );
 928         vout_DisplayPicture( p_vpar->p_vout, P_picture );
 929
 930         /* Prepare context for the next picture. */
 931         P_picture = NULL;
 932         p_vpar->picture.i_current_structure = 0;
 933     }
 934 #undef P_picture
 935 }
 936
 937 /*****************************************************************************
 938  * ExtensionAndUserData : Parse the extension_and_user_data structure
 939  *****************************************************************************/
 940 static void ExtensionAndUserData( vpar_thread_t * p_vpar )
 941 {
 942     while( !p_vpar->p_fifo->b_die )
 943     {
 944         NextStartCode( &p_vpar->bit_stream );
 945         switch( ShowBits( &p_vpar->bit_stream, 32 ) )
 946         {
 947         case EXTENSION_START_CODE:
 948             RemoveBits32( &p_vpar->bit_stream );
 949             switch( GetBits( &p_vpar->bit_stream, 4 ) )
 950             {
 951             case SEQUENCE_DISPLAY_EXTENSION_ID:
 952                 SequenceDisplayExtension( p_vpar );
 953                 break;
 954             case QUANT_MATRIX_EXTENSION_ID:
 955                 QuantMatrixExtension( p_vpar );
 956                 break;
 957             case SEQUENCE_SCALABLE_EXTENSION_ID:
 958                 SequenceScalableExtension( p_vpar );
 959                 break;
 960             case PICTURE_DISPLAY_EXTENSION_ID:
 961                 PictureDisplayExtension( p_vpar );
 962                 break;
 963             case PICTURE_SPATIAL_SCALABLE_EXTENSION_ID:
 964                 PictureSpatialScalableExtension( p_vpar );
 965                 break;
 966             case PICTURE_TEMPORAL_SCALABLE_EXTENSION_ID:
 967                 PictureTemporalScalableExtension( p_vpar );
 968                 break;
 969             case COPYRIGHT_EXTENSION_ID:
 970                 CopyrightExtension( p_vpar );
 971                 break;
 972             default:
 973                 break;
 974             }
 975             break;
 976
 977         case USER_DATA_START_CODE:
 978             RemoveBits32( &p_vpar->bit_stream );
 979             /* Wait for the next start code */
 980             break;
 981
 982         default:
 983             return;
 984         }
 985     }
 986 }
 987
 988
 989 /*****************************************************************************
 990  * SequenceDisplayExtension : Parse the sequence_display_extension structure *
 991  *****************************************************************************/
 992
 993 static void SequenceDisplayExtension( vpar_thread_t * p_vpar )
 994 {
 995     /* We don't care sequence_display_extension. */
 996     /* video_format */
 997     RemoveBits( &p_vpar->bit_stream, 3 );
 998     if( GetBits( &p_vpar->bit_stream, 1 ) )
 999     {
1000         /* Two bytes for color_desciption */
1001         RemoveBits( &p_vpar->bit_stream, 16 );
1002         p_vpar->sequence.i_matrix_coefficients = GetBits( &p_vpar->bit_stream, 8 );
1003     }
1004     /* display_horizontal and vertical_size and a marker_bit */
1005     RemoveBits( &p_vpar->bit_stream, 29 );
1006 }
1007
1008
1009 /*****************************************************************************
1010  * QuantMatrixExtension : Load quantization matrices for luminance           *
1011  *                        and chrominance                                    *
1012  *****************************************************************************/
1013
1014 static void QuantMatrixExtension( vpar_thread_t * p_vpar )
1015 {
1016     if( GetBits( &p_vpar->bit_stream, 1 ) )
1017     {
1018         /* Load intra_quantiser_matrix for luminance. */
1019         LoadMatrix( p_vpar, &p_vpar->sequence.intra_quant );
1020     }
1021     else
1022     {
1023         /* Use the default matrix. */
1024         LinkMatrix( &p_vpar->sequence.intra_quant,
1025                     p_vpar->pi_default_intra_quant );
1026     }
1027     if( GetBits( &p_vpar->bit_stream, 1 ) )
1028     {
1029         /* Load non_intra_quantiser_matrix for luminance. */
1030         LoadMatrix( p_vpar, &p_vpar->sequence.nonintra_quant );
1031     }
1032     else
1033     {
1034         /* Use the default matrix. */
1035         LinkMatrix( &p_vpar->sequence.nonintra_quant,
1036                     p_vpar->pi_default_nonintra_quant );
1037     }
1038     if( GetBits( &p_vpar->bit_stream, 1 ) )
1039     {
1040         /* Load intra_quantiser_matrix for chrominance. */
1041         LoadMatrix( p_vpar, &p_vpar->sequence.chroma_intra_quant );
1042     }
1043     else
1044     {
1045         /* Link the chrominance intra matrix to the luminance one. */
1046         LinkMatrix( &p_vpar->sequence.chroma_intra_quant,
1047                     p_vpar->sequence.intra_quant.pi_matrix );
1048     }
1049     if( GetBits( &p_vpar->bit_stream, 1 ) )
1050     {
1051         /* Load non_intra_quantiser_matrix for chrominance. */
1052         LoadMatrix( p_vpar, &p_vpar->sequence.chroma_nonintra_quant );
1053     }
1054     else
1055     {
1056         /* Link the chrominance nonintra matrix to the luminance one. */
1057         LinkMatrix( &p_vpar->sequence.chroma_nonintra_quant,
1058                     p_vpar->sequence.nonintra_quant.pi_matrix );
1059     }
1060 }
1061
1062
1063 /*****************************************************************************
1064  * SequenceScalableExtension : Parse the sequence_scalable_extension         *
1065  *                             structure to handle scalable coding           *
1066  *****************************************************************************/
1067
1068 static void SequenceScalableExtension( vpar_thread_t * p_vpar )
1069 {
1070     /* We don't care about anything scalable except the scalable mode. */
1071     switch( p_vpar->sequence.i_scalable_mode = GetBits( &p_vpar->bit_stream, 2 ) )
1072     /* The length of the structure depends on the value of the scalable_mode */
1073     {
1074         case 1:
1075             RemoveBits32( &p_vpar->bit_stream );
1076             RemoveBits( &p_vpar->bit_stream, 21 );
1077             break;
1078         case 2:
1079             RemoveBits( &p_vpar->bit_stream, 12 );
1080             break;
1081         default:
1082             RemoveBits( &p_vpar->bit_stream, 4 );
1083     }
1084
1085 }
1086 /*****************************************************************************
1087  * PictureDisplayExtension : Parse the picture_display_extension structure   *
1088  *****************************************************************************/
1089
1090 static void PictureDisplayExtension( vpar_thread_t * p_vpar )
1091 {
1092     /* Number of frame center offset */
1093     int i_nb, i_dummy;
1094     /* I am not sure it works but it should
1095         (fewer tests than shown in §6.3.12) */
1096     /* FIXME: is VLC_TRUE always 1 ? */
1097     i_nb = p_vpar->sequence.b_progressive ? p_vpar->sequence.b_progressive +
1098                                             p_vpar->picture.b_repeat_first_field +
1099                                             p_vpar->picture.b_top_field_first
1100                            : ( p_vpar->picture.b_frame_structure + 1 ) +
1101                              p_vpar->picture.b_repeat_first_field;
1102     for( i_dummy = 0; i_dummy < i_nb && !p_vpar->p_fifo->b_die
1103                        && !p_vpar->p_fifo->b_error; i_dummy++ )
1104     {
1105         RemoveBits( &p_vpar->bit_stream, 17 );
1106         RemoveBits( &p_vpar->bit_stream, 17 );
1107     }
1108 }
1109
1110
1111 /*****************************************************************************
1112  * PictureSpatialScalableExtension                                           *
1113  *****************************************************************************/
1114
1115 static void PictureSpatialScalableExtension( vpar_thread_t * p_vpar )
1116 {
1117     /* That's scalable, so we trash it */
1118     RemoveBits32( &p_vpar->bit_stream );
1119     RemoveBits( &p_vpar->bit_stream, 16 );
1120 }
1121
1122
1123 /*****************************************************************************
1124  * PictureTemporalScalableExtension                                          *
1125  *****************************************************************************/
1126
1127 static void PictureTemporalScalableExtension( vpar_thread_t * p_vpar )
1128 {
1129     /* Scalable again, trashed again */
1130     RemoveBits( &p_vpar->bit_stream, 23 );
1131 }
1132
1133
1134 /*****************************************************************************
1135  * CopyrightExtension : Keeps some legal informations                        *
1136  *****************************************************************************/
1137
1138 static void CopyrightExtension( vpar_thread_t * p_vpar )
1139 {
1140     u32     i_copyright_nb_1, i_copyright_nb_2; /* local integers */
1141     p_vpar->sequence.b_copyright_flag = GetBits( &p_vpar->bit_stream, 1 );
1142         /* A flag that says whether the copyright information is significant */
1143     p_vpar->sequence.i_copyright_id = GetBits( &p_vpar->bit_stream, 8 );
1144         /* An identifier compliant with ISO/CEI JTC 1/SC 29 */
1145     p_vpar->sequence.b_original = GetBits( &p_vpar->bit_stream, 1 );
1146         /* Reserved bits */
1147     RemoveBits( &p_vpar->bit_stream, 8 );
1148         /* The copyright_number is split in three parts */
1149         /* first part */
1150     i_copyright_nb_1 = GetBits( &p_vpar->bit_stream, 20 );
1151     RemoveBits( &p_vpar->bit_stream, 1 );
1152         /* second part */
1153     i_copyright_nb_2 = GetBits( &p_vpar->bit_stream, 22 );
1154     RemoveBits( &p_vpar->bit_stream, 1 );
1155         /* third part and sum */
1156     p_vpar->sequence.i_copyright_nb = ( (u64)i_copyright_nb_1 << 44 ) |
1157                                       ( (u64)i_copyright_nb_2 << 22 ) |
1158                                       ( (u64)GetBits( &p_vpar->bit_stream, 22 ) );
1159 }