git.sesse.net Git - vlc/blob - modules/codec/libmpeg2.c

   1 /*****************************************************************************
   2  * libmpeg2.c: mpeg2 video decoder module making use of libmpeg2.
   3  *****************************************************************************
   4  * Copyright (C) 1999-2001 VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@videolan.org>
   8  *          Christophe Massiot <massiot@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 <vlc/vlc.h>
  29 #include <vlc/vout.h>
  30 #include <vlc/decoder.h>
  31
  32 #include <mpeg2dec/mpeg2.h>
  33
  34 #include "vout_synchro.h"
  35
  36 /* Aspect ratio (ISO/IEC 13818-2 section 6.3.3, table 6-3) */
  37 #define AR_SQUARE_PICTURE       1                           /* square pixels */
  38 #define AR_3_4_PICTURE          2                        /* 3:4 picture (TV) */
  39 #define AR_16_9_PICTURE         3              /* 16:9 picture (wide screen) */
  40 #define AR_221_1_PICTURE        4                  /* 2.21:1 picture (movie) */
  41
  42 /*****************************************************************************
  43  * decoder_sys_t : libmpeg2 decoder descriptor
  44  *****************************************************************************/
  45 struct decoder_sys_t
  46 {
  47     /*
  48      * libmpeg2 properties
  49      */
  50     mpeg2dec_t          *p_mpeg2dec;
  51     const mpeg2_info_t  *p_info;
  52     vlc_bool_t          b_skip;
  53
  54     /*
  55      * Input properties
  56      */
  57     mtime_t          i_previous_pts;
  58     mtime_t          i_current_pts;
  59     mtime_t          i_previous_dts;
  60     mtime_t          i_current_dts;
  61     int              i_current_rate;
  62     picture_t *      p_picture_to_destroy;
  63     vlc_bool_t       b_garbage_pic;
  64     vlc_bool_t       b_after_sequence_header; /* is it the next frame after
  65                                                * the sequence header ?    */
  66     vlc_bool_t       b_slice_i;             /* intra-slice refresh stream */
  67
  68     /*
  69      * Output properties
  70      */
  71     vout_synchro_t *p_synchro;
  72     int            i_aspect;
  73     mtime_t        i_last_frame_pts;
  74
  75 };
  76
  77 /*****************************************************************************
  78  * Local prototypes
  79  *****************************************************************************/
  80 static int  OpenDecoder( vlc_object_t * );
  81 static void CloseDecoder( vlc_object_t * );
  82
  83 static picture_t *DecodeBlock( decoder_t *, block_t ** );
  84
  85 static picture_t *GetNewPicture( decoder_t *, uint8_t ** );
  86
  87 /*****************************************************************************
  88  * Module descriptor
  89  *****************************************************************************/
  90 vlc_module_begin();
  91     set_description( _("MPEG I/II video decoder (using libmpeg2)") );
  92     set_capability( "decoder", 150 );
  93     set_callbacks( OpenDecoder, CloseDecoder );
  94     add_shortcut( "libmpeg2" );
  95 vlc_module_end();
  96
  97 /*****************************************************************************
  98  * OpenDecoder: probe the decoder and return score
  99  *****************************************************************************/
 100 static int OpenDecoder( vlc_object_t *p_this )
 101 {
 102     decoder_t *p_dec = (decoder_t*)p_this;
 103     decoder_sys_t *p_sys;
 104     uint32_t i_accel = 0;
 105
 106     if( p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','v') &&
 107         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','1') &&
 108         /* Pinnacle hardware-mpeg1 */
 109         p_dec->fmt_in.i_codec != VLC_FOURCC('P','I','M','1') &&
 110         /* ATI Video */
 111         p_dec->fmt_in.i_codec != VLC_FOURCC('V','C','R','2') &&
 112         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','2') )
 113     {
 114         return VLC_EGENERIC;
 115     }
 116
 117     /* Allocate the memory needed to store the decoder's structure */
 118     if( ( p_dec->p_sys = p_sys =
 119           (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
 120     {
 121         msg_Err( p_dec, "out of memory" );
 122         return VLC_EGENERIC;
 123     }
 124
 125     /* Initialize the thread properties */
 126     memset( p_sys, 0, sizeof(decoder_sys_t) );
 127     p_sys->p_mpeg2dec = NULL;
 128     p_sys->p_synchro  = NULL;
 129     p_sys->p_info     = NULL;
 130     p_sys->i_current_pts  = 0;
 131     p_sys->i_previous_pts = 0;
 132     p_sys->i_current_dts  = 0;
 133     p_sys->i_previous_dts = 0;
 134     p_sys->p_picture_to_destroy = NULL;
 135     p_sys->b_garbage_pic = 0;
 136     p_sys->b_slice_i  = 0;
 137     p_sys->b_skip     = 0;
 138
 139 #if defined( __i386__ )
 140     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_MMX )
 141     {
 142         i_accel |= MPEG2_ACCEL_X86_MMX;
 143     }
 144
 145     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_3DNOW )
 146     {
 147         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 148     }
 149
 150     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_MMXEXT )
 151     {
 152         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 153     }
 154
 155 #elif defined( __powerpc__ ) || defined( SYS_DARWIN )
 156     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_ALTIVEC )
 157     {
 158         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
 159     }
 160
 161 #else
 162     /* If we do not know this CPU, trust libmpeg2's feature detection */
 163     i_accel = MPEG2_ACCEL_DETECT;
 164
 165 #endif
 166
 167     /* Set CPU acceleration features */
 168     mpeg2_accel( i_accel );
 169
 170     /* Initialize decoder */
 171     p_sys->p_mpeg2dec = mpeg2_init();
 172     if( p_sys->p_mpeg2dec == NULL)
 173     {
 174         msg_Err( p_dec, "mpeg2_init() failed" );
 175         free( p_sys );
 176         return VLC_EGENERIC;
 177     }
 178
 179     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
 180
 181     p_dec->pf_decode_video = DecodeBlock;
 182
 183     return VLC_SUCCESS;
 184 }
 185
 186 /*****************************************************************************
 187  * RunDecoder: the libmpeg2 decoder
 188  *****************************************************************************/
 189 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 190 {
 191     decoder_sys_t   *p_sys = p_dec->p_sys;
 192     mpeg2_state_t   state;
 193     picture_t       *p_pic;
 194
 195     block_t *p_block;
 196
 197     if( !pp_block || !*pp_block ) return NULL;
 198
 199     p_block = *pp_block;
 200
 201     while( 1 )
 202     {
 203         state = mpeg2_parse( p_sys->p_mpeg2dec );
 204
 205         switch( state )
 206         {
 207         case STATE_BUFFER:
 208             if( !p_block->i_buffer )
 209             {
 210                 block_Release( p_block );
 211                 return NULL;
 212             }
 213
 214             if( (p_block->i_flags&BLOCK_FLAG_DISCONTINUITY) &&
 215                 p_sys->p_synchro &&
 216                 p_sys->p_info->sequence &&
 217                 p_sys->p_info->sequence->width != (unsigned)-1 )
 218             {
 219                 vout_SynchroReset( p_sys->p_synchro );
 220                 if( p_sys->p_info->current_fbuf != NULL
 221                     && p_sys->p_info->current_fbuf->id != NULL )
 222                 {
 223                     p_sys->b_garbage_pic = 1;
 224                     p_pic = p_sys->p_info->current_fbuf->id;
 225                 }
 226                 else
 227                 {
 228                     uint8_t *buf[3];
 229                     buf[0] = buf[1] = buf[2] = NULL;
 230                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 231                         break;
 232                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 233                 }
 234                 p_sys->p_picture_to_destroy = p_pic;
 235
 236                 if ( p_sys->b_slice_i )
 237                 {
 238                     vout_SynchroNewPicture( p_sys->p_synchro,
 239                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate );
 240                     vout_SynchroDecode( p_sys->p_synchro );
 241                     vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 242                 }
 243             }
 244
 245 #ifdef PIC_FLAG_PTS
 246             if( p_block->i_pts )
 247             {
 248                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 249
 250 #else /* New interface */
 251             if( p_block->i_pts || p_block->i_dts )
 252             {
 253                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
 254                                    (uint32_t)p_block->i_pts,
 255                                    (uint32_t)p_block->i_dts );
 256 #endif
 257                 p_sys->i_previous_pts = p_sys->i_current_pts;
 258                 p_sys->i_current_pts = p_block->i_pts;
 259                 p_sys->i_previous_dts = p_sys->i_current_dts;
 260                 p_sys->i_current_dts = p_block->i_dts;
 261             }
 262
 263             p_sys->i_current_rate = p_block->i_rate;
 264
 265             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 266                           p_block->p_buffer + p_block->i_buffer );
 267
 268             p_block->i_buffer = 0;
 269             break;
 270
 271         case STATE_SEQUENCE:
 272         {
 273             /* Initialize video output */
 274             uint8_t *buf[3];
 275             buf[0] = buf[1] = buf[2] = NULL;
 276
 277             /* Check whether the input gave a particular aspect ratio */
 278             if( p_dec->fmt_in.video.i_aspect )
 279             {
 280                 p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 281                 if( p_sys->i_aspect <= AR_221_1_PICTURE )
 282                 switch( p_sys->i_aspect )
 283                 {
 284                 case AR_3_4_PICTURE:
 285                     p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 286                     break;
 287                 case AR_16_9_PICTURE:
 288                     p_sys->i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 289                     break;
 290                 case AR_221_1_PICTURE:
 291                     p_sys->i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 292                     break;
 293                 case AR_SQUARE_PICTURE:
 294                     p_sys->i_aspect = VOUT_ASPECT_FACTOR *
 295                                    p_sys->p_info->sequence->width /
 296                                    p_sys->p_info->sequence->height;
 297                     break;
 298                 }
 299             }
 300             else
 301             {
 302                 /* Use the value provided in the MPEG sequence header */
 303                 if( p_sys->p_info->sequence->pixel_height > 0 )
 304                 {
 305                     p_sys->i_aspect =
 306                         ((uint64_t)p_sys->p_info->sequence->display_width) *
 307                         p_sys->p_info->sequence->pixel_width *
 308                         VOUT_ASPECT_FACTOR /
 309                         p_sys->p_info->sequence->display_height /
 310                         p_sys->p_info->sequence->pixel_height;
 311                 }
 312                 else
 313                 {
 314                     /* Invalid aspect, assume 4:3.
 315                      * This shouldn't happen and if it does it is a bug
 316                      * in libmpeg2 (likely triggered by an invalid stream) */
 317                     p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 318                 }
 319             }
 320
 321             msg_Dbg( p_dec, "%dx%d, aspect %d, %u.%03u fps",
 322                      p_sys->p_info->sequence->width,
 323                      p_sys->p_info->sequence->height, p_sys->i_aspect,
 324                      (uint32_t)((uint64_t)1001000000 * 27 /
 325                          p_sys->p_info->sequence->frame_period / 1001),
 326                      (uint32_t)((uint64_t)1001000000 * 27 /
 327                          p_sys->p_info->sequence->frame_period % 1001) );
 328
 329             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 330
 331             /* Set the first 2 reference frames */
 332             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 333
 334             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 335             {
 336                 block_Release( p_block );
 337                 return NULL;
 338             }
 339
 340             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 341
 342             /* This picture will never go through display_picture. */
 343             p_pic->date = 0;
 344
 345             /* For some reason, libmpeg2 will put this pic twice in
 346              * discard_picture. This can be considered a bug in libmpeg2. */
 347             p_dec->pf_picture_link( p_dec, p_pic );
 348
 349             if( p_sys->p_synchro )
 350             {
 351                 vout_SynchroRelease( p_sys->p_synchro );
 352             }
 353             p_sys->p_synchro = vout_SynchroInit( p_dec,
 354                 (uint32_t)((uint64_t)1001000000 * 27 /
 355                 p_sys->p_info->sequence->frame_period) );
 356             p_sys->b_after_sequence_header = 1;
 357         }
 358         break;
 359
 360         case STATE_PICTURE_2ND:
 361             vout_SynchroNewPicture( p_sys->p_synchro,
 362                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 363                 p_sys->p_info->current_picture->nb_fields,
 364                 0, 0, p_sys->i_current_rate );
 365
 366             if( p_sys->b_skip )
 367             {
 368                 vout_SynchroTrash( p_sys->p_synchro );
 369             }
 370             else
 371             {
 372                 vout_SynchroDecode( p_sys->p_synchro );
 373             }
 374             break;
 375
 376         case STATE_PICTURE:
 377         {
 378             uint8_t *buf[3];
 379             mtime_t i_pts, i_dts;
 380             buf[0] = buf[1] = buf[2] = NULL;
 381
 382             if ( p_sys->b_after_sequence_header &&
 383                  ((p_sys->p_info->current_picture->flags &
 384                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
 385             {
 386                 /* Intra-slice refresh. Simulate a blank I picture. */
 387                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 388                 vout_SynchroNewPicture( p_sys->p_synchro,
 389                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate );
 390                 vout_SynchroDecode( p_sys->p_synchro );
 391                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 392                 p_sys->b_slice_i = 1;
 393             }
 394             p_sys->b_after_sequence_header = 0;
 395
 396 #ifdef PIC_FLAG_PTS
 397             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
 398                 ( ( p_sys->p_info->current_picture->pts ==
 399                     (uint32_t)p_sys->i_current_pts ) ?
 400                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 401             i_dts = 0;
 402
 403             /* Hack to handle demuxers which only have DTS timestamps */
 404             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 405             {
 406                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 407                     (p_sys->p_info->current_picture->flags &
 408                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 409                 {
 410                     i_pts = p_block->i_dts;
 411                 }
 412             }
 413             p_block->i_pts = p_block->i_dts = 0;
 414             /* End hack */
 415
 416 #else /* New interface */
 417
 418             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 419                 ( ( p_sys->p_info->current_picture->tag ==
 420                     (uint32_t)p_sys->i_current_pts ) ?
 421                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 422             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 423                 ( ( p_sys->p_info->current_picture->tag2 ==
 424                     (uint32_t)p_sys->i_current_dts ) ?
 425                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 426 #endif
 427
 428             vout_SynchroNewPicture( p_sys->p_synchro,
 429                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 430                 p_sys->p_info->current_picture->nb_fields, i_pts, i_dts,
 431                 p_sys->i_current_rate );
 432
 433             if ( !(p_sys->b_slice_i
 434                    && ((p_sys->p_info->current_picture->flags
 435                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
 436                    && !vout_SynchroChoose( p_sys->p_synchro,
 437                               p_sys->p_info->current_picture->flags
 438                                 & PIC_MASK_CODING_TYPE,
 439                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/ ) )
 440             {
 441                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 442                 p_sys->b_skip = 1;
 443                 vout_SynchroTrash( p_sys->p_synchro );
 444                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 445             }
 446             else
 447             {
 448                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 449                 p_sys->b_skip = 0;
 450                 vout_SynchroDecode( p_sys->p_synchro );
 451
 452                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 453                 {
 454                     block_Release( p_block );
 455                     return NULL;
 456                 }
 457
 458                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 459             }
 460         }
 461         break;
 462
 463         case STATE_END:
 464         case STATE_SLICE:
 465             p_pic = NULL;
 466             if( p_sys->p_info->display_fbuf
 467                 && p_sys->p_info->display_fbuf->id )
 468             {
 469                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 470
 471                 vout_SynchroEnd( p_sys->p_synchro,
 472                             p_sys->p_info->display_picture->flags
 473                              & PIC_MASK_CODING_TYPE,
 474                             p_sys->b_garbage_pic );
 475                 p_sys->b_garbage_pic = 0;
 476
 477                 if ( p_sys->p_picture_to_destroy != p_pic )
 478                 {
 479                     p_pic->date = vout_SynchroDate( p_sys->p_synchro );
 480                 }
 481                 else
 482                 {
 483                     p_sys->p_picture_to_destroy = NULL;
 484                     p_pic->date = 0;
 485                 }
 486             }
 487
 488             if( p_sys->p_info->discard_fbuf &&
 489                 p_sys->p_info->discard_fbuf->id )
 490             {
 491                 p_dec->pf_picture_unlink( p_dec,
 492                                           p_sys->p_info->discard_fbuf->id );
 493             }
 494
 495             /* For still frames */
 496             if( state == STATE_END && p_pic ) p_pic->b_force = VLC_TRUE;
 497
 498             if( p_pic )
 499             {
 500                 /* Avoid frames with identical timestamps.
 501                  * Especially needed for still frames in DVD menus. */
 502                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
 503                 p_sys->i_last_frame_pts = p_pic->date;
 504
 505                 return p_pic;
 506             }
 507
 508             break;
 509
 510         case STATE_INVALID:
 511         {
 512             uint8_t *buf[3];
 513             buf[0] = buf[1] = buf[2] = NULL;
 514
 515             msg_Warn( p_dec, "invalid picture encountered" );
 516             if ( ( p_sys->p_info->current_picture == NULL ) ||
 517                ( ( p_sys->p_info->current_picture->flags &
 518                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
 519             {
 520                 if( p_sys->p_synchro ) vout_SynchroReset( p_sys->p_synchro );
 521             }
 522             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 523             p_sys->b_skip = 1;
 524
 525             if( p_sys->p_info->current_fbuf &&
 526                 p_sys->p_info->current_fbuf->id )
 527             {
 528                 p_sys->b_garbage_pic = 1;
 529                 p_pic = p_sys->p_info->current_fbuf->id;
 530             }
 531             else if( !p_sys->p_info->sequence )
 532             {
 533                 break;
 534             }
 535             else
 536             {
 537                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 538                     break;
 539                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 540             }
 541             p_sys->p_picture_to_destroy = p_pic;
 542
 543             memset( p_pic->p[0].p_pixels, 0,
 544                     p_sys->p_info->sequence->width
 545                      * p_sys->p_info->sequence->height );
 546             memset( p_pic->p[1].p_pixels, 0x80,
 547                     p_sys->p_info->sequence->width
 548                      * p_sys->p_info->sequence->height / 4 );
 549             memset( p_pic->p[2].p_pixels, 0x80,
 550                     p_sys->p_info->sequence->width
 551                      * p_sys->p_info->sequence->height / 4 );
 552
 553             if( p_sys->b_slice_i )
 554             {
 555                 vout_SynchroNewPicture( p_sys->p_synchro,
 556                             I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate );
 557                 vout_SynchroDecode( p_sys->p_synchro );
 558                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 559             }
 560             break;
 561         }
 562
 563         default:
 564             break;
 565         }
 566     }
 567
 568     /* Never reached */
 569     return NULL;
 570 }
 571
 572 /*****************************************************************************
 573  * CloseDecoder: libmpeg2 decoder destruction
 574  *****************************************************************************/
 575 static void CloseDecoder( vlc_object_t *p_this )
 576 {
 577     decoder_t *p_dec = (decoder_t *)p_this;
 578     decoder_sys_t *p_sys = p_dec->p_sys;
 579
 580     if( p_sys->p_synchro ) vout_SynchroRelease( p_sys->p_synchro );
 581
 582     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 583
 584     free( p_sys );
 585 }
 586
 587 /*****************************************************************************
 588  * GetNewPicture: Get a new picture from the vout and set the buf struct
 589  *****************************************************************************/
 590 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
 591 {
 592     decoder_sys_t *p_sys = p_dec->p_sys;
 593     picture_t *p_pic;
 594
 595     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
 596     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
 597     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
 598
 599     p_dec->fmt_out.i_codec =
 600         ( p_sys->p_info->sequence->chroma_height <
 601           p_sys->p_info->sequence->height ) ?
 602         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
 603
 604     /* Get a new picture */
 605     p_pic = p_dec->pf_vout_buffer_new( p_dec );
 606
 607     if( p_pic == NULL ) return NULL;
 608
 609     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 610         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 611     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 612         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 613     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 614         p_sys->p_info->current_picture->nb_fields : 2;
 615
 616     p_dec->pf_picture_link( p_dec, p_pic );
 617
 618     pp_buf[0] = p_pic->p[0].p_pixels;
 619     pp_buf[1] = p_pic->p[1].p_pixels;
 620     pp_buf[2] = p_pic->p[2].p_pixels;
 621
 622     return p_pic;
 623 }