git.sesse.net Git - vlc/blob - modules/packetizer/vc1.c

   1 /*****************************************************************************
   2  * vc1.c
   3  *****************************************************************************
   4  * Copyright (C) 2001, 2002, 2006 the VideoLAN team
   5  * $Id: copy.c 18231 2006-12-03 17:02:02Z courmisch $
   6  *
   7  * Authors: Laurent Aimar <fenrir@via.ecp.fr>
   8  *          Gildas Bazin <gbazin@videolan.org>
   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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #include <stdlib.h>                                      /* malloc(), free() */
  29
  30 #include <vlc/vlc.h>
  31 #include <vlc_codec.h>
  32 #include <vlc_block.h>
  33
  34 #include "vlc_bits.h"
  35 #include "vlc_block_helper.h"
  36
  37 /*****************************************************************************
  38  * Module descriptor
  39  *****************************************************************************/
  40 static int  Open ( vlc_object_t * );
  41 static void Close( vlc_object_t * );
  42
  43 vlc_module_begin();
  44     set_category( CAT_SOUT );
  45     set_subcategory( SUBCAT_SOUT_PACKETIZER );
  46     set_description( _("VC-1 packetizer") );
  47     set_capability( "packetizer", 50 );
  48     set_callbacks( Open, Close );
  49 vlc_module_end();
  50
  51 /*****************************************************************************
  52  * Local prototypes
  53  *****************************************************************************/
  54 struct decoder_sys_t
  55 {
  56     /*
  57      * Input properties
  58      */
  59     block_bytestream_t bytestream;
  60     int i_state;
  61     int i_offset;
  62     uint8_t p_startcode[3];
  63
  64     /* Current sequence header */
  65     vlc_bool_t b_sequence_header;
  66     struct
  67     {
  68         block_t *p_sh;
  69         vlc_bool_t b_advanced_profile;
  70         vlc_bool_t b_interlaced;
  71         vlc_bool_t b_frame_interpolation;
  72         vlc_bool_t b_range_reduction;
  73         vlc_bool_t b_has_bframe;
  74     } sh;
  75     vlc_bool_t b_entry_point;
  76     struct
  77     {
  78         block_t *p_ep;
  79     } ep;
  80
  81     /* */
  82     vlc_bool_t  b_frame;
  83
  84     /* Current frame being built */
  85     block_t    *p_frame;
  86     block_t    **pp_last;
  87
  88
  89     mtime_t i_interpolated_dts;
  90 };
  91
  92 enum
  93 {
  94     STATE_NOSYNC,
  95     STATE_NEXT_SYNC
  96 };
  97
  98 typedef enum
  99 {
 100     IDU_TYPE_SEQUENCE_HEADER = 0x0f,
 101     IDU_TYPE_ENTRY_POINT = 0x0e,
 102     IDU_TYPE_FRAME = 0x0D,
 103     IDU_TYPE_FIELD = 0x0C,
 104     IDU_TYPE_SLICE = 0x0B,
 105     IDU_TYPE_END_OF_SEQUENCE = 0x0B,
 106
 107     IDU_TYPE_SEQUENCE_LEVEL_USER_DATA = 0x1F,
 108     IDU_TYPE_ENTRY_POINT_USER_DATA = 0x1E,
 109     IDU_TYPE_FRAME_USER_DATA = 0x1D,
 110     IDU_TYPE_FIELD_USER_DATA = 0x1C,
 111     IDU_TYPE_SLICE_USER_DATA = 0x1B,
 112 } idu_type_t;
 113
 114 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block );
 115
 116 /*****************************************************************************
 117  * Open: probe the packetizer and return score
 118  *****************************************************************************
 119  * Tries to launch a decoder and return score so that the interface is able
 120  * to choose.
 121  *****************************************************************************/
 122 static int Open( vlc_object_t *p_this )
 123 {
 124     decoder_t     *p_dec = (decoder_t*)p_this;
 125     decoder_sys_t *p_sys;
 126
 127     if( p_dec->fmt_in.i_codec !=  VLC_FOURCC( 'W', 'V', 'C', '1' ) )
 128         return VLC_EGENERIC;
 129
 130     p_dec->pf_packetize = Packetize;
 131
 132     /* Create the output format */
 133     es_format_Copy( &p_dec->fmt_out, &p_dec->fmt_in );
 134     p_dec->p_sys = p_sys = malloc( sizeof( decoder_sys_t ) );
 135
 136     p_sys->i_state = STATE_NOSYNC;
 137     p_sys->bytestream = block_BytestreamInit( p_dec );
 138     p_sys->p_startcode[0] = 0x00;
 139     p_sys->p_startcode[1] = 0x00;
 140     p_sys->p_startcode[2] = 0x01;
 141     p_sys->i_offset = 0;
 142
 143     p_sys->b_sequence_header = VLC_FALSE;
 144     p_sys->sh.p_sh = NULL;
 145     p_sys->b_entry_point = VLC_FALSE;
 146     p_sys->ep.p_ep = NULL;
 147
 148     p_sys->b_frame = VLC_FALSE;
 149     p_sys->p_frame = NULL;
 150     p_sys->pp_last = &p_sys->p_frame;
 151
 152     p_sys->i_interpolated_dts = -1;
 153
 154
 155     if( p_dec->fmt_in.i_extra > 0 )
 156     {
 157         block_t *p_init = block_New( p_dec, p_dec->fmt_in.i_extra );
 158         block_t *p_pic;
 159
 160         memcpy( p_init->p_buffer, p_dec->fmt_in.p_extra,
 161                 p_dec->fmt_in.i_extra );
 162
 163         while( ( p_pic = Packetize( p_dec, &p_init ) ) )
 164             block_Release( p_pic ); /* Should not happen (only sequence header) */
 165     }
 166
 167     return VLC_SUCCESS;
 168 }
 169
 170 /*****************************************************************************
 171  * Close:
 172  *****************************************************************************/
 173 static void Close( vlc_object_t *p_this )
 174 {
 175     decoder_t     *p_dec = (decoder_t*)p_this;
 176     decoder_sys_t *p_sys = p_dec->p_sys;
 177
 178     block_BytestreamRelease( &p_sys->bytestream );
 179     if( p_sys->p_frame )
 180         block_Release( p_sys->p_frame );
 181     free( p_sys );
 182 }
 183
 184 /*****************************************************************************
 185  * Packetize: packetize an access unit
 186  *****************************************************************************/
 187 static block_t *ParseIDU( decoder_t *p_dec, block_t *p_frag );
 188
 189 static block_t *Packetize( decoder_t *p_dec, block_t **pp_block )
 190 {
 191     decoder_sys_t *p_sys = p_dec->p_sys;
 192     block_t       *p_pic;
 193
 194     if( pp_block == NULL || *pp_block == NULL )
 195         return NULL;
 196
 197     if( (*pp_block)->i_flags & BLOCK_FLAG_DISCONTINUITY )
 198     {
 199         block_Release( *pp_block );
 200         return NULL;
 201     }
 202     if( (*pp_block)->i_flags & BLOCK_FLAG_CORRUPTED )
 203     {
 204         p_sys->i_state = STATE_NOSYNC;
 205         if( p_sys->p_frame )
 206             block_ChainRelease( p_sys->p_frame );
 207         p_sys->p_frame = NULL;
 208         p_sys->pp_last = &p_sys->p_frame;
 209         block_Release( *pp_block );
 210         return NULL;
 211     }
 212
 213     block_BytestreamPush( &p_sys->bytestream, *pp_block );
 214
 215     for( ;; )
 216     {
 217         switch( p_sys->i_state )
 218         {
 219
 220         case STATE_NOSYNC:
 221             if( block_FindStartcodeFromOffset( &p_sys->bytestream, &p_sys->i_offset, p_sys->p_startcode, 3 ) == VLC_SUCCESS )
 222                 p_sys->i_state = STATE_NEXT_SYNC;
 223
 224             if( p_sys->i_offset )
 225             {
 226                 block_SkipBytes( &p_sys->bytestream, p_sys->i_offset );
 227                 p_sys->i_offset = 0;
 228                 block_BytestreamFlush( &p_sys->bytestream );
 229             }
 230
 231             if( p_sys->i_state != STATE_NEXT_SYNC )
 232                 return NULL; /* Need more data */
 233
 234             p_sys->i_offset = 4; /* To find next startcode */
 235
 236         case STATE_NEXT_SYNC:
 237             /* TODO: If p_block == NULL, flush the buffer without checking the
 238              * next sync word */
 239
 240             /* Find the next startcode */
 241             if( block_FindStartcodeFromOffset( &p_sys->bytestream, &p_sys->i_offset, p_sys->p_startcode, 3 ) != VLC_SUCCESS )
 242                 return NULL; /* Need more data */
 243
 244             /* Get the new fragment and set the pts/dts */
 245             p_pic = block_New( p_dec, p_sys->i_offset );
 246             block_BytestreamFlush( &p_sys->bytestream );
 247             p_pic->i_pts = p_sys->bytestream.p_block->i_pts;
 248             p_pic->i_dts = p_sys->bytestream.p_block->i_dts;
 249             p_pic->i_rate = p_sys->bytestream.p_block->i_rate;
 250
 251             block_GetBytes( &p_sys->bytestream, p_pic->p_buffer, p_pic->i_buffer );
 252
 253             p_sys->i_offset = 0;
 254
 255             /* Parse and return complete frame */
 256             p_pic = ParseIDU( p_dec, p_pic );
 257
 258             /* Don't reuse the same timestamps several times */
 259             if( p_sys->p_frame &&
 260                 p_sys->p_frame->i_dts == p_sys->bytestream.p_block->i_dts &&
 261                 p_sys->p_frame->i_pts == p_sys->bytestream.p_block->i_pts )
 262             {
 263                 p_sys->bytestream.p_block->i_pts = -1;
 264                 p_sys->bytestream.p_block->i_dts = -1;
 265             }
 266
 267             /* */
 268             if( !p_pic )
 269             {
 270                 p_sys->i_state = STATE_NOSYNC;
 271                 break;
 272             }
 273             /* */
 274             if( p_sys->i_interpolated_dts < 0 )
 275             {
 276                 msg_Dbg( p_dec, "need a starting pts/dts" );
 277                 p_sys->i_state = STATE_NOSYNC;
 278                 block_Release( p_pic );
 279                 break;
 280             }
 281
 282             /* So p_block doesn't get re-added several times */
 283             *pp_block = block_BytestreamPop( &p_sys->bytestream );
 284
 285             p_sys->i_state = STATE_NOSYNC;
 286
 287             return p_pic;
 288         }
 289     }
 290 }
 291
 292 /* DecodeRIDU: decode the startcode emulation prevention (same than h264) */
 293 static void DecodeRIDU( uint8_t *p_ret, int *pi_ret, uint8_t *src, int i_src )
 294 {
 295     uint8_t *end = &src[i_src];
 296     uint8_t *dst_end = &p_ret[*pi_ret];
 297     uint8_t *dst = p_ret;
 298
 299     while( src < end && dst < dst_end )
 300     {
 301         if( src < end - 3 && src[0] == 0x00 && src[1] == 0x00 &&
 302             src[2] == 0x03 )
 303         {
 304             *dst++ = 0x00;
 305             *dst++ = 0x00;
 306
 307             src += 3;
 308             continue;
 309         }
 310         *dst++ = *src++;
 311     }
 312
 313     *pi_ret = dst - p_ret;
 314 }
 315 /* BuildExtraData: gather sequence header and entry point */
 316 static void BuildExtraData( decoder_t *p_dec )
 317 {
 318     decoder_sys_t *p_sys = p_dec->p_sys;
 319     es_format_t *p_es = &p_dec->fmt_out;
 320     int i_extra;
 321     if( !p_sys->b_sequence_header || !p_sys->b_entry_point )
 322         return;
 323
 324     i_extra = p_sys->sh.p_sh->i_buffer + p_sys->ep.p_ep->i_buffer;
 325     if( p_es->i_extra != i_extra )
 326     {
 327         p_es->i_extra = i_extra;
 328         p_es->p_extra = realloc( p_dec->fmt_out.p_extra, p_es->i_extra );
 329     }
 330     memcpy( p_es->p_extra,
 331             p_sys->sh.p_sh->p_buffer, p_sys->sh.p_sh->i_buffer );
 332     memcpy( (uint8_t*)p_es->p_extra + p_sys->sh.p_sh->i_buffer,
 333             p_sys->ep.p_ep->p_buffer, p_sys->ep.p_ep->i_buffer );
 334 }
 335 /* ParseIDU: parse an Independant Decoding Unit */
 336 static block_t *ParseIDU( decoder_t *p_dec, block_t *p_frag )
 337 {
 338     decoder_sys_t *p_sys = p_dec->p_sys;
 339     block_t *p_pic;
 340     const idu_type_t idu = p_frag->p_buffer[3];
 341
 342     if( !p_sys->b_sequence_header && idu != IDU_TYPE_SEQUENCE_HEADER )
 343     {
 344         msg_Warn( p_dec, "waiting for sequence header" );
 345         block_Release( p_frag );
 346         return NULL;
 347     }
 348     if( p_sys->b_sequence_header && !p_sys->b_entry_point && idu != IDU_TYPE_ENTRY_POINT )
 349     {
 350         msg_Warn( p_dec, "waiting for entry point" );
 351         block_Release( p_frag );
 352         return NULL;
 353     }
 354     /* TODO we do not gather ENTRY_POINT and SEQUENCE_DATA user data
 355      * But It should not be a problem for decoder */
 356
 357     /* Do we have completed a frame */
 358     p_pic = NULL;
 359     if( p_sys->b_frame &&
 360         idu != IDU_TYPE_FRAME_USER_DATA &&
 361         idu != IDU_TYPE_FIELD && idu != IDU_TYPE_FIELD_USER_DATA &&
 362         idu != IDU_TYPE_SLICE && idu != IDU_TYPE_SLICE_USER_DATA &&
 363         idu != IDU_TYPE_END_OF_SEQUENCE )
 364     {
 365         /* */
 366         p_pic = block_ChainGather( p_sys->p_frame );
 367
 368         /* We can interpolate dts/pts only if we have a frame rate */
 369         if( p_dec->fmt_out.video.i_frame_rate != 0 && p_dec->fmt_out.video.i_frame_rate_base != 0 )
 370         {
 371             //msg_Dbg( p_dec, "-------------- XXX0 dts="I64Fd" pts="I64Fd" interpolated="I64Fd, p_pic->i_dts, p_pic->i_pts, p_sys->i_interpolated_dts );
 372             if( p_pic->i_dts <= 0 )
 373                 p_pic->i_dts = p_sys->i_interpolated_dts;
 374
 375             p_sys->i_interpolated_dts += I64C(1000000) * p_dec->fmt_out.video.i_frame_rate_base / p_dec->fmt_out.video.i_frame_rate;
 376             if( p_pic->i_pts <= 0 )
 377             {
 378                 if( !p_sys->sh.b_has_bframe || (p_pic->i_flags & BLOCK_FLAG_TYPE_B ) )
 379                     p_pic->i_pts = p_pic->i_dts;
 380                 /* TODO compute pts for other case */
 381             }
 382         }
 383         p_sys->i_interpolated_dts = p_pic->i_dts;
 384
 385         //msg_Dbg( p_dec, "-------------- dts="I64Fd" pts="I64Fd, p_pic->i_dts, p_pic->i_pts );
 386
 387         /* Reset context */
 388         p_sys->p_frame = NULL;
 389         p_sys->pp_last = &p_sys->p_frame;
 390     }
 391
 392     /*  */
 393     if( p_sys->p_frame )
 394     {
 395         block_t *p_frame = p_sys->p_frame;
 396         if( p_frame->i_dts < 0 )
 397             p_frame->i_dts = p_frag->i_dts;
 398         if( p_frame->i_pts < 0 )
 399             p_frame->i_pts = p_frag->i_pts;
 400     }
 401     block_ChainLastAppend( &p_sys->pp_last, p_frag );
 402
 403     /* Parse IDU */
 404     if( idu == IDU_TYPE_SEQUENCE_HEADER )
 405     {
 406         es_format_t *p_es = &p_dec->fmt_out;
 407         bs_t s;
 408         int i_profile;
 409         uint8_t ridu[32];
 410         int     i_ridu = sizeof(ridu);
 411
 412         /* */
 413         if( p_sys->sh.p_sh )
 414             block_Release( p_sys->sh.p_sh );
 415         p_sys->sh.p_sh = block_Duplicate( p_frag );
 416
 417         /* Extract the raw IDU */
 418         DecodeRIDU( ridu, &i_ridu, &p_frag->p_buffer[4], p_frag->i_buffer - 4 );
 419
 420         /* Auto detect VC-1_SPMP_PESpacket_PayloadFormatHeader (SMPTE RP 227) for simple/main profile
 421          * TODO find a test case and valid it */
 422         if( i_ridu > 4 && (ridu[0]&0x80) == 0 ) /* for advanced profile, the first bit is 1 */
 423         {
 424             video_format_t *p_v = &p_dec->fmt_in.video;
 425             const int i_potential_width  = GetWBE( &ridu[0] );
 426             const int i_potential_height = GetWBE( &ridu[2] );
 427
 428             if( i_potential_width >= 2  && i_potential_width <= 8192 &&
 429                 i_potential_height >= 2 && i_potential_height <= 8192 )
 430             {
 431                 if( ( p_v->i_width <= 0 && p_v->i_height <= 0  ) ||
 432                     ( p_v->i_width  == i_potential_width &&  p_v->i_height == i_potential_height ) )
 433                 {
 434                     static const uint8_t startcode[4] = { 0x00, 0x00, 0x01, IDU_TYPE_SEQUENCE_HEADER };
 435                     p_es->video.i_width  = i_potential_width;
 436                     p_es->video.i_height = i_potential_height;
 437
 438                     /* Remove it */
 439                     p_frag->p_buffer += 4;
 440                     p_frag->i_buffer -= 4;
 441                     memcpy( p_frag->p_buffer, startcode, sizeof(startcode) );
 442                 }
 443             }
 444         }
 445
 446         /* Parse it */
 447         bs_init( &s, ridu, i_ridu );
 448         i_profile = bs_read( &s, 2 );
 449         if( i_profile == 3 )
 450         {
 451             const int i_level = bs_read( &s, 3 );
 452
 453             /* Advanced profile */
 454             p_sys->sh.b_advanced_profile = VLC_TRUE;
 455             p_sys->sh.b_range_reduction = VLC_FALSE;
 456             p_sys->sh.b_has_bframe = VLC_TRUE;
 457
 458             bs_skip( &s, 2+3+5+1 ); // chroma format + frame rate Q + bit rate Q + postprocflag
 459
 460             p_es->video.i_width  = 2*bs_read( &s, 12 )+2;
 461             p_es->video.i_height = 2*bs_read( &s, 12 )+2;
 462
 463             if( !p_sys->b_sequence_header )
 464                 msg_Dbg( p_dec, "found sequence header for advanced profile level L%d resolution %dx%d",
 465                          i_level, p_es->video.i_width, p_es->video.i_height);
 466
 467             bs_skip( &s, 1 );// pulldown
 468             p_sys->sh.b_interlaced = bs_read( &s, 1 );
 469             bs_skip( &s, 1 );// frame counter
 470             p_sys->sh.b_frame_interpolation = bs_read( &s, 1 );
 471             bs_skip( &s, 1 );       // Reserved
 472             bs_skip( &s, 1 );       // Psf
 473
 474             if( bs_read( &s, 1 ) )  /* Display extension */
 475             {
 476                 const int i_display_width  = bs_read( &s, 14 )+1;
 477                 const int i_display_height = bs_read( &s, 14 )+1;
 478
 479                 p_es->video.i_aspect = VOUT_ASPECT_FACTOR * i_display_width / i_display_height;
 480
 481                 if( !p_sys->b_sequence_header )
 482                     msg_Dbg( p_dec, "display size %dx%d", i_display_width, i_display_height );
 483
 484                 if( bs_read( &s, 1 ) )  /* Pixel aspect ratio (PAR/SAR) */
 485                 {
 486                     static const int p_ar[16][2] = {
 487                         { 0, 0}, { 1, 1}, {12,11}, {10,11}, {16,11}, {40,33},
 488                         {24,11}, {20,11}, {32,11}, {80,33}, {18,11}, {15,11},
 489                         {64,33}, {160,99},{ 0, 0}, { 0, 0}
 490                     };
 491                     int i_ar = bs_read( &s, 4 );
 492                     int i_ar_w, i_ar_h;
 493
 494                     if( i_ar == 15 )
 495                     {
 496                         i_ar_w = bs_read( &s, 8 );
 497                         i_ar_h = bs_read( &s, 8 );
 498                     }
 499                     else
 500                     {
 501                         i_ar_w = p_ar[i_ar][0];
 502                         i_ar_h = p_ar[i_ar][1];
 503                     }
 504                     vlc_ureduce( &i_ar_w, &i_ar_h, i_ar_w, i_ar_h, 0 );
 505                     if( !p_sys->b_sequence_header )
 506                         msg_Dbg( p_dec, "aspect ratio %d:%d", i_ar_w, i_ar_h );
 507                 }
 508             }
 509             if( bs_read( &s, 1 ) )  /* Frame rate */
 510             {
 511                 int i_fps_num = 0;
 512                 int i_fps_den = 0;
 513                 if( bs_read( &s, 1 ) )
 514                 {
 515                     i_fps_num = bs_read( &s, 16 )+1;
 516                     i_fps_den = 32;
 517                 }
 518                 else
 519                 {
 520                     const int i_nr = bs_read( &s, 8 );
 521                     const int i_dn = bs_read( &s, 4 );
 522
 523                     switch( i_nr )
 524                     {
 525                     case 1: i_fps_num = 24000; break;
 526                     case 2: i_fps_num = 25000; break;
 527                     case 3: i_fps_num = 30000; break;
 528                     case 4: i_fps_num = 50000; break;
 529                     case 5: i_fps_num = 60000; break;
 530                     case 6: i_fps_num = 48000; break;
 531                     case 7: i_fps_num = 72000; break;
 532                     }
 533                     switch( i_dn )
 534                     {
 535                     case 1: i_fps_den = 1000; break;
 536                     case 2: i_fps_den = 1001; break;
 537                     }
 538                 }
 539                 if( i_fps_num != 0 && i_fps_den != 0 )
 540                     vlc_ureduce( &p_es->video.i_frame_rate, &p_es->video.i_frame_rate_base, i_fps_num, i_fps_den, 0 );
 541
 542                 if( !p_sys->b_sequence_header )
 543                     msg_Dbg( p_dec, "frame rate %d/%d", p_es->video.i_frame_rate, p_es->video.i_frame_rate_base );
 544             }
 545         }
 546         else
 547         {
 548             /* Simple and main profile */
 549             p_sys->sh.b_advanced_profile = VLC_FALSE;
 550             p_sys->sh.b_interlaced = VLC_FALSE;
 551
 552             if( !p_sys->b_sequence_header )
 553                 msg_Dbg( p_dec, "found sequence header for %s profile", i_profile == 0 ? "simple" : "main" );
 554
 555             bs_skip( &s, 2+3+5+1+1+     // reserved + frame rate Q + bit rate Q + loop filter + reserved
 556                          1+1+1+1+2+     // multiresolution + reserved + fast uv mc + extended mv + dquant
 557                          1+1+1+1 );     // variable size transform + reserved + overlap + sync marker
 558             p_sys->sh.b_range_reduction = bs_read( &s, 1 );
 559             if( bs_read( &s, 3 ) > 0 )
 560                 p_sys->sh.b_has_bframe = VLC_TRUE;
 561             else
 562                 p_sys->sh.b_has_bframe = VLC_FALSE;
 563             bs_skip( &s, 2 );           // quantizer
 564
 565             p_sys->sh.b_frame_interpolation = bs_read( &s, 1 );
 566         }
 567         p_sys->b_sequence_header = VLC_TRUE;
 568         BuildExtraData( p_dec );
 569     }
 570     else if( idu == IDU_TYPE_ENTRY_POINT )
 571     {
 572         if( p_sys->ep.p_ep )
 573             block_Release( p_sys->ep.p_ep );
 574         p_sys->ep.p_ep = block_Duplicate( p_frag );
 575
 576         p_sys->b_entry_point = VLC_TRUE;
 577         BuildExtraData( p_dec );
 578     }
 579     else if( idu == IDU_TYPE_FRAME )
 580     {
 581         bs_t s;
 582         uint8_t ridu[8];
 583         int     i_ridu = sizeof(ridu);
 584
 585         /* Extract the raw IDU */
 586         DecodeRIDU( ridu, &i_ridu, &p_frag->p_buffer[4], p_frag->i_buffer - 4 );
 587
 588         /* Parse it + interpolate pts/dts if possible */
 589         bs_init( &s, ridu, i_ridu );
 590
 591         if( p_sys->sh.b_advanced_profile )
 592         {
 593             int i_fcm = 0;
 594
 595             if( p_sys->sh.b_interlaced )
 596             {
 597                 if( bs_read( &s, 1 ) )
 598                 {
 599                     if( bs_read( &s, 1 ) )
 600                         i_fcm = 1;  /* interlaced field */
 601                     else
 602                         i_fcm = 2;  /* interlaced frame */
 603                 }
 604             }
 605
 606             if( i_fcm == 1 ) /*interlaced field */
 607             {
 608                 /* XXX for mixed I/P we should check reference usage before marking them I (too much work) */
 609                 switch( bs_read( &s, 3 ) )
 610                 {
 611                 case 0: /* II */
 612                 case 1: /* IP */
 613                 case 2: /* PI */
 614                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_I;
 615                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_I;
 616                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_I;
 617                     break;
 618                 case 3: /* PP */
 619                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_P;
 620                     break;
 621                 case 4: /* BB */
 622                 case 5: /* BBi */
 623                 case 6: /* BiB */
 624                 case 7: /* BiBi */
 625                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_B;
 626                     break;
 627                 }
 628             }
 629             else
 630             {
 631                 if( !bs_read( &s, 1 ) )
 632                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_P;
 633                 else if( !bs_read( &s, 1 ) )
 634                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_B;
 635                 else if( !bs_read( &s, 1 ) )
 636                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_I;
 637                 else if( !bs_read( &s, 1 ) )
 638                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_B;   /* Bi */
 639                 else
 640                     p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_P;   /* P Skip */
 641             }
 642         }
 643         else
 644         {
 645             if( p_sys->sh.b_frame_interpolation )
 646                 bs_skip( &s, 1 );   // interpolate
 647             bs_skip( &s, 2 );       // frame count
 648             if( p_sys->sh.b_range_reduction )
 649                 bs_skip( &s, 1 );   // range reduction
 650
 651             if( bs_read( &s, 1 ) )
 652                 p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_P;
 653             else if( !p_sys->sh.b_has_bframe || bs_read( &s, 1 ) )
 654                 p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_I;
 655             else
 656                 p_sys->p_frame->i_flags |= BLOCK_FLAG_TYPE_B;
 657         }
 658         p_sys->b_frame = VLC_TRUE;
 659     }
 660     return p_pic;
 661 }
 662