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: libmpeg2.c,v 1.31 2003/10/25 00:49:13 sam Exp $
   6  *
   7  * Authors: Gildas Bazin <gbazin@netcourrier.com>
   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/input.h>
  31 #include <vlc/decoder.h>
  32
  33 #include <stdlib.h>                                      /* malloc(), free() */
  34 #include <string.h>                                    /* memcpy(), memset() */
  35
  36 #include <mpeg2dec/mpeg2.h>
  37
  38 #include "vout_synchro.h"
  39
  40 /* Aspect ratio (ISO/IEC 13818-2 section 6.3.3, table 6-3) */
  41 #define AR_SQUARE_PICTURE       1                           /* square pixels */
  42 #define AR_3_4_PICTURE          2                        /* 3:4 picture (TV) */
  43 #define AR_16_9_PICTURE         3              /* 16:9 picture (wide screen) */
  44 #define AR_221_1_PICTURE        4                  /* 2.21:1 picture (movie) */
  45
  46 /*****************************************************************************
  47  * decoder_sys_t : libmpeg2 decoder descriptor
  48  *****************************************************************************/
  49 struct decoder_sys_t
  50 {
  51     /*
  52      * libmpeg2 properties
  53      */
  54     mpeg2dec_t          *p_mpeg2dec;
  55     const mpeg2_info_t  *p_info;
  56     vlc_bool_t          b_skip;
  57
  58     /*
  59      * Input properties
  60      */
  61     pes_packet_t     *p_pes;                  /* current PES we are decoding */
  62     mtime_t          i_pts;
  63     mtime_t          i_previous_pts;
  64     mtime_t          i_current_pts;
  65     int              i_current_rate;
  66     picture_t *      p_picture_to_destroy;
  67     vlc_bool_t       b_garbage_pic;
  68     vlc_bool_t       b_after_sequence_header; /* is it the next frame after
  69                                                * the sequence header ?    */
  70     vlc_bool_t       b_slice_i;             /* intra-slice refresh stream */
  71
  72     /*
  73      * Output properties
  74      */
  75     vout_thread_t *p_vout;
  76     vout_synchro_t *p_synchro;
  77
  78 };
  79
  80 /*****************************************************************************
  81  * Local prototypes
  82  *****************************************************************************/
  83 static int OpenDecoder( vlc_object_t * );
  84 static int InitDecoder( decoder_t * );
  85 static int RunDecoder ( decoder_t *, block_t * );
  86 static int EndDecoder ( decoder_t * );
  87
  88 static picture_t *GetNewPicture( decoder_t *, uint8_t ** );
  89
  90 /*****************************************************************************
  91  * Module descriptor
  92  *****************************************************************************/
  93 vlc_module_begin();
  94     set_description( _("MPEG I/II video decoder (using libmpeg2)") );
  95     set_capability( "decoder", 150 );
  96     set_callbacks( OpenDecoder, NULL );
  97     add_shortcut( "libmpeg2" );
  98 vlc_module_end();
  99
 100 /*****************************************************************************
 101  * OpenDecoder: probe the decoder and return score
 102  *****************************************************************************/
 103 static int OpenDecoder( vlc_object_t *p_this )
 104 {
 105     decoder_t *p_dec = (decoder_t*)p_this;
 106
 107     if( p_dec->p_fifo->i_fourcc != VLC_FOURCC('m','p','g','v') &&
 108         p_dec->p_fifo->i_fourcc != VLC_FOURCC('m','p','g','1') &&
 109         /* Pinnacle hardware-mpeg1 */
 110         p_dec->p_fifo->i_fourcc != VLC_FOURCC('P','I','M','1') &&
 111         /* ATI Video */
 112         p_dec->p_fifo->i_fourcc != VLC_FOURCC('V','C','R','2') &&
 113         p_dec->p_fifo->i_fourcc != VLC_FOURCC('m','p','g','2') )
 114     {
 115         return VLC_EGENERIC;
 116     }
 117
 118     p_dec->pf_init = InitDecoder;
 119     p_dec->pf_decode = RunDecoder;
 120     p_dec->pf_end = EndDecoder;
 121
 122     return VLC_SUCCESS;
 123 }
 124
 125 /*****************************************************************************
 126  * InitDecoder: Initalize the decoder
 127  *****************************************************************************/
 128 static int InitDecoder( decoder_t *p_dec )
 129 {
 130     /* Allocate the memory needed to store the decoder's structure */
 131     if( ( p_dec->p_sys =
 132           (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
 133     {
 134         msg_Err( p_dec, "out of memory" );
 135         return VLC_EGENERIC;
 136     }
 137
 138     /* Initialize the thread properties */
 139     memset( p_dec->p_sys, 0, sizeof(decoder_sys_t) );
 140     p_dec->p_sys->p_pes      = NULL;
 141     p_dec->p_sys->p_vout     = NULL;
 142     p_dec->p_sys->p_mpeg2dec = NULL;
 143     p_dec->p_sys->p_synchro  = NULL;
 144     p_dec->p_sys->p_info     = NULL;
 145     p_dec->p_sys->i_pts      = mdate() + DEFAULT_PTS_DELAY;
 146     p_dec->p_sys->i_current_pts  = 0;
 147     p_dec->p_sys->i_previous_pts = 0;
 148     p_dec->p_sys->p_picture_to_destroy = NULL;
 149     p_dec->p_sys->b_garbage_pic = 0;
 150     p_dec->p_sys->b_slice_i  = 0;
 151     p_dec->p_sys->b_skip     = 0;
 152
 153     /* Initialize decoder */
 154     p_dec->p_sys->p_mpeg2dec = mpeg2_init();
 155     if( p_dec->p_sys->p_mpeg2dec == NULL)
 156     {
 157         msg_Err( p_dec, "mpeg2_init() failed" );
 158         free( p_dec->p_sys );
 159         return VLC_EGENERIC;
 160     }
 161
 162     p_dec->p_sys->p_info = mpeg2_info( p_dec->p_sys->p_mpeg2dec );
 163
 164     return VLC_SUCCESS;
 165 }
 166
 167 /*****************************************************************************
 168  * RunDecoder: the libmpeg2 decoder
 169  *****************************************************************************/
 170 static int RunDecoder( decoder_t *p_dec, block_t *p_block )
 171 {
 172     decoder_sys_t   *p_sys = p_dec->p_sys;
 173     mpeg2_state_t   state;
 174     picture_t       *p_pic;
 175     int             i_aspect;
 176
 177     vlc_bool_t      b_need_more_data = VLC_FALSE;
 178
 179     while( 1 )
 180     {
 181         if( p_dec->p_fifo->b_die || p_dec->p_fifo->b_error )
 182         {
 183             block_Release( p_block );
 184             return VLC_EGENERIC;
 185         }
 186
 187         state = mpeg2_parse( p_sys->p_mpeg2dec );
 188
 189         switch( state )
 190         {
 191         case STATE_BUFFER:
 192             if( !p_block->i_buffer || b_need_more_data )
 193             {
 194                 block_Release( p_block );
 195                 return VLC_SUCCESS;
 196             }
 197
 198             if( p_block->b_discontinuity && p_sys->p_synchro
 199                 && p_sys->p_info->sequence->width != (unsigned)-1 )
 200             {
 201                 vout_SynchroReset( p_sys->p_synchro );
 202                 if( p_sys->p_info->current_fbuf != NULL
 203                     && p_sys->p_info->current_fbuf->id != NULL )
 204                 {
 205                     p_sys->b_garbage_pic = 1;
 206                     p_pic = p_sys->p_info->current_fbuf->id;
 207                 }
 208                 else
 209                 {
 210                     uint8_t *buf[3];
 211                     buf[0] = buf[1] = buf[2] = NULL;
 212                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 213                         break;
 214                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 215                 }
 216                 p_sys->p_picture_to_destroy = p_pic;
 217
 218                 memset( p_pic->p[0].p_pixels, 0,
 219                         p_sys->p_info->sequence->width
 220                          * p_sys->p_info->sequence->height );
 221                 memset( p_pic->p[1].p_pixels, 0x80,
 222                         p_sys->p_info->sequence->width
 223                          * p_sys->p_info->sequence->height / 4 );
 224                 memset( p_pic->p[2].p_pixels, 0x80,
 225                         p_sys->p_info->sequence->width
 226                          * p_sys->p_info->sequence->height / 4 );
 227
 228                 if ( p_sys->b_slice_i )
 229                 {
 230                     vout_SynchroNewPicture( p_sys->p_synchro,
 231                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate );
 232                     vout_SynchroDecode( p_sys->p_synchro );
 233                     vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 234                 }
 235             }
 236
 237             if( p_block->i_pts )
 238             {
 239                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 240                 p_sys->i_previous_pts = p_sys->i_current_pts;
 241                 p_sys->i_current_pts = p_block->i_pts;
 242             }
 243
 244             p_sys->i_current_rate = DEFAULT_RATE;//p_pes->i_rate;
 245
 246             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 247                           p_block->p_buffer + p_block->i_buffer );
 248
 249             b_need_more_data = VLC_TRUE;
 250             break;
 251
 252         case STATE_SEQUENCE:
 253         {
 254             /* Initialize video output */
 255             uint8_t *buf[3];
 256             buf[0] = buf[1] = buf[2] = NULL;
 257
 258             /* Check whether the input gives a particular aspect ratio */
 259             if( p_dec->p_fifo->p_demux_data
 260                 && ( *(int*)(p_dec->p_fifo->p_demux_data) & 0x7 ) )
 261             {
 262                 i_aspect = *(int*)(p_dec->p_fifo->p_demux_data);
 263                 switch( i_aspect )
 264                 {
 265                 case AR_3_4_PICTURE:
 266                     i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 267                     break;
 268                 case AR_16_9_PICTURE:
 269                     i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 270                     break;
 271                 case AR_221_1_PICTURE:
 272                     i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 273                     break;
 274                 case AR_SQUARE_PICTURE:
 275                 default:
 276                     i_aspect = VOUT_ASPECT_FACTOR *
 277                                    p_sys->p_info->sequence->width /
 278                                    p_sys->p_info->sequence->height;
 279                     break;
 280                 }
 281             }
 282             else
 283             {
 284                 /* Use the value provided in the MPEG sequence header */
 285                 i_aspect = ((uint64_t)p_sys->p_info->sequence->display_width) *
 286                     p_sys->p_info->sequence->pixel_width * VOUT_ASPECT_FACTOR /
 287                     p_sys->p_info->sequence->display_height /
 288                     p_sys->p_info->sequence->pixel_height;
 289             }
 290
 291             if ( p_dec->p_sys->p_vout != NULL )
 292             {
 293               int i_pic;
 294                 /* Temporary hack to free the pictures in use by libmpeg2 */
 295                 for ( i_pic = 0; i_pic < p_dec->p_sys->p_vout->render.i_pictures; i_pic++ )
 296                 {
 297                     if( p_dec->p_sys->p_vout->render.pp_picture[i_pic]->i_status ==
 298                           RESERVED_PICTURE )
 299                         vout_DestroyPicture( p_dec->p_sys->p_vout,
 300                                          p_dec->p_sys->p_vout->render.pp_picture[i_pic] );
 301                     if( p_dec->p_sys->p_vout->render.pp_picture[i_pic]->i_refcount > 0 )
 302                         vout_UnlinkPicture( p_dec->p_sys->p_vout,
 303                                          p_dec->p_sys->p_vout->render.pp_picture[i_pic] );
 304                 }
 305             }
 306
 307             p_sys->p_vout = vout_Request( p_dec, p_sys->p_vout,
 308                                           p_sys->p_info->sequence->width,
 309                                           p_sys->p_info->sequence->height,
 310                                           VLC_FOURCC('Y','V','1','2'),
 311                                           i_aspect );
 312
 313             if(p_sys->p_vout == NULL )
 314             {
 315                 msg_Err( p_dec, "cannot create vout" );
 316                 block_Release( p_block );
 317                 return -1;
 318             }
 319
 320             msg_Dbg( p_dec, "%dx%d, aspect %d, %u.%03u fps",
 321                      p_sys->p_info->sequence->width,
 322                      p_sys->p_info->sequence->height, i_aspect,
 323                      (uint32_t)((uint64_t)1001000000 * 27 /
 324                                  p_sys->p_info->sequence->frame_period / 1001),
 325                      (uint32_t)((uint64_t)1001000000 * 27 /
 326                                  p_sys->p_info->sequence->frame_period % 1001) );
 327
 328             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 329
 330             /* Set the first 2 reference frames */
 331             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 332
 333             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL ) break;
 334             memset( p_pic->p[0].p_pixels, 0,
 335                     p_sys->p_info->sequence->width
 336                      * p_sys->p_info->sequence->height );
 337             memset( p_pic->p[1].p_pixels, 0x80,
 338                     p_sys->p_info->sequence->width
 339                      * p_sys->p_info->sequence->height / 4 );
 340             memset( p_pic->p[2].p_pixels, 0x80,
 341                     p_sys->p_info->sequence->width
 342                      * p_sys->p_info->sequence->height / 4 );
 343             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 344             /* This picture will never go through display_picture. */
 345             vout_DatePicture( p_sys->p_vout, p_pic, 0 );
 346             vout_DisplayPicture( p_sys->p_vout, p_pic );
 347             /* For some reason, libmpeg2 will put this pic twice in
 348              * discard_picture. This can be considered a bug in libmpeg2. */
 349             vout_LinkPicture( p_sys->p_vout, p_pic );
 350
 351             if ( p_sys->p_synchro )
 352             {
 353                 vout_SynchroRelease( p_sys->p_synchro );
 354             }
 355             p_sys->p_synchro = vout_SynchroInit( p_dec, p_sys->p_vout,
 356                 (uint32_t)((uint64_t)1001000000 * 27 /
 357                 p_sys->p_info->sequence->frame_period) );
 358             p_sys->b_after_sequence_header = 1;
 359         }
 360         break;
 361
 362         case STATE_PICTURE_2ND:
 363             vout_SynchroNewPicture( p_sys->p_synchro,
 364                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 365                 p_sys->p_info->current_picture->nb_fields,
 366                 0, 0,
 367                 p_sys->i_current_rate );
 368
 369             if ( p_sys->b_skip )
 370             {
 371                 vout_SynchroTrash( p_sys->p_synchro );
 372             }
 373             else
 374             {
 375                 vout_SynchroDecode( p_sys->p_synchro );
 376             }
 377             break;
 378
 379         case STATE_PICTURE:
 380         {
 381             uint8_t *buf[3];
 382             buf[0] = buf[1] = buf[2] = NULL;
 383
 384             if ( p_sys->b_after_sequence_header
 385                   && ((p_sys->p_info->current_picture->flags
 386                         & PIC_MASK_CODING_TYPE)
 387                        == PIC_FLAG_CODING_TYPE_P) )
 388             {
 389                 /* Intra-slice refresh. Simulate a blank I picture. */
 390                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 391                 vout_SynchroNewPicture( p_sys->p_synchro,
 392                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate );
 393                 vout_SynchroDecode( p_sys->p_synchro );
 394                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 395                 p_sys->b_slice_i = 1;
 396             }
 397             p_sys->b_after_sequence_header = 0;
 398
 399             vout_SynchroNewPicture( p_sys->p_synchro,
 400                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 401                 p_sys->p_info->current_picture->nb_fields,
 402                 (p_sys->p_info->current_picture->flags & PIC_FLAG_PTS) ?
 403                     ( ( p_sys->p_info->current_picture->pts ==
 404                         (uint32_t)p_sys->i_current_pts ) ?
 405                       p_sys->i_current_pts : p_sys->i_previous_pts ) : 0,
 406                 0, p_sys->i_current_rate );
 407
 408             if ( !(p_sys->b_slice_i
 409                    && ((p_sys->p_info->current_picture->flags
 410                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
 411                    && !vout_SynchroChoose( p_sys->p_synchro,
 412                               p_sys->p_info->current_picture->flags
 413                                 & PIC_MASK_CODING_TYPE ) )
 414             {
 415                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 416                 p_sys->b_skip = 1;
 417                 vout_SynchroTrash( p_sys->p_synchro );
 418                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 419             }
 420             else
 421             {
 422                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 423                 p_sys->b_skip = 0;
 424                 vout_SynchroDecode( p_sys->p_synchro );
 425                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL ) break;
 426                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 427             }
 428         }
 429         break;
 430
 431         case STATE_END:
 432         case STATE_SLICE:
 433             if( p_sys->p_info->display_fbuf
 434                 && p_sys->p_info->display_fbuf->id )
 435             {
 436                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 437
 438                 vout_SynchroEnd( p_sys->p_synchro,
 439                             p_sys->p_info->display_picture->flags
 440                              & PIC_MASK_CODING_TYPE,
 441                             p_sys->b_garbage_pic );
 442                 p_sys->b_garbage_pic = 0;
 443                 vout_DisplayPicture( p_sys->p_vout, p_pic );
 444
 445                 if ( p_sys->p_picture_to_destroy != p_pic )
 446                 {
 447                     vout_DatePicture( p_sys->p_vout, p_pic,
 448                         vout_SynchroDate( p_sys->p_synchro ) );
 449                 }
 450                 else
 451                 {
 452                     p_sys->p_picture_to_destroy = NULL;
 453                     vout_DatePicture( p_sys->p_vout, p_pic, 0 );
 454                 }
 455             }
 456
 457             if( p_sys->p_info->discard_fbuf &&
 458                 p_sys->p_info->discard_fbuf->id )
 459             {
 460                 p_pic = (picture_t *)p_sys->p_info->discard_fbuf->id;
 461                 vout_UnlinkPicture( p_sys->p_vout, p_pic );
 462             }
 463             break;
 464
 465         case STATE_INVALID:
 466         {
 467             uint8_t *buf[3];
 468             buf[0] = buf[1] = buf[2] = NULL;
 469
 470             msg_Warn( p_dec, "invalid picture encountered" );
 471             if ( ( p_sys->p_info->current_picture == NULL ) ||
 472                ( ( p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE)
 473                   != B_CODING_TYPE ) )
 474             {
 475                 vout_SynchroReset( p_sys->p_synchro );
 476             }
 477             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 478             p_sys->b_skip = 1;
 479
 480             if( p_sys->p_info->current_fbuf &&
 481                 p_sys->p_info->current_fbuf->id )
 482             {
 483                 p_sys->b_garbage_pic = 1;
 484                 p_pic = p_sys->p_info->current_fbuf->id;
 485             }
 486             else
 487             {
 488                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 489                     break;
 490                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 491             }
 492             p_sys->p_picture_to_destroy = p_pic;
 493
 494             memset( p_pic->p[0].p_pixels, 0,
 495                     p_sys->p_info->sequence->width
 496                      * p_sys->p_info->sequence->height );
 497             memset( p_pic->p[1].p_pixels, 0x80,
 498                     p_sys->p_info->sequence->width
 499                      * p_sys->p_info->sequence->height / 4 );
 500             memset( p_pic->p[2].p_pixels, 0x80,
 501                     p_sys->p_info->sequence->width
 502                      * p_sys->p_info->sequence->height / 4 );
 503
 504             if ( p_sys->b_slice_i )
 505             {
 506                 vout_SynchroNewPicture( p_sys->p_synchro,
 507                             I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate );
 508                 vout_SynchroDecode( p_sys->p_synchro );
 509                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 510             }
 511             break;
 512         }
 513
 514         default:
 515             break;
 516         }
 517     }
 518
 519     block_Release( p_block );
 520     return VLC_EGENERIC;
 521 }
 522
 523 /*****************************************************************************
 524  * EndDecoder: libmpeg2 decoder destruction
 525  *****************************************************************************/
 526 static int EndDecoder( decoder_t * p_dec )
 527 {
 528     decoder_sys_t *p_sys = p_dec->p_sys;
 529
 530     if( p_sys )
 531     {
 532         int i_pic;
 533
 534         if( p_sys->p_synchro )
 535             vout_SynchroRelease( p_sys->p_synchro );
 536
 537         if( p_sys->p_vout )
 538         {
 539             /* Temporary hack to free the pictures in use by libmpeg2 */
 540             for( i_pic = 0; i_pic < p_sys->p_vout->render.i_pictures; i_pic++ )
 541             {
 542                 if( p_sys->p_vout->render.pp_picture[i_pic]->i_status ==
 543                       RESERVED_PICTURE )
 544                     vout_DestroyPicture( p_sys->p_vout,
 545                                      p_sys->p_vout->render.pp_picture[i_pic] );
 546                 if( p_sys->p_vout->render.pp_picture[i_pic]->i_refcount > 0 )
 547                     vout_UnlinkPicture( p_sys->p_vout,
 548                                      p_sys->p_vout->render.pp_picture[i_pic] );
 549             }
 550
 551             vout_Request( p_dec, p_sys->p_vout, 0, 0, 0, 0 );
 552         }
 553
 554         if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 555
 556         free( p_sys );
 557     }
 558
 559     return VLC_SUCCESS;
 560 }
 561
 562 /*****************************************************************************
 563  * GetNewPicture: Get a new picture from the vout and set the buf struct
 564  *****************************************************************************/
 565 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
 566 {
 567     decoder_sys_t *p_sys = p_dec->p_sys;
 568     picture_t *p_pic;
 569
 570     vlc_bool_t b_progressive = p_sys->p_info->current_picture != NULL ?
 571         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 572     vlc_bool_t b_top_field_first = p_sys->p_info->current_picture != NULL ?
 573         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 574     unsigned int i_nb_fields = p_sys->p_info->current_picture != NULL ?
 575         p_sys->p_info->current_picture->nb_fields : 2;
 576
 577     /* Get a new picture */
 578     while( !( p_pic = vout_CreatePicture( p_sys->p_vout,
 579               b_progressive, b_top_field_first, i_nb_fields ) ) )
 580     {
 581         if( p_dec->p_fifo->b_die || p_dec->p_fifo->b_error )
 582             break;
 583
 584         msleep( VOUT_OUTMEM_SLEEP );
 585     }
 586
 587     if( p_pic == NULL ) return NULL;
 588
 589     vout_LinkPicture( p_sys->p_vout, p_pic );
 590
 591     pp_buf[0] = p_pic->p[0].p_pixels;
 592     pp_buf[1] = p_pic->p[1].p_pixels;
 593     pp_buf[2] = p_pic->p[2].p_pixels;
 594
 595     return p_pic;
 596 }