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 the VideoLAN team
   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., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_vout.h>
  35 #include <vlc_codec.h>
  36
  37 #include <mpeg2.h>
  38
  39 #include <vlc_codec_synchro.h>
  40
  41 /*****************************************************************************
  42  * decoder_sys_t : libmpeg2 decoder descriptor
  43  *****************************************************************************/
  44 struct decoder_sys_t
  45 {
  46     /*
  47      * libmpeg2 properties
  48      */
  49     mpeg2dec_t          *p_mpeg2dec;
  50     const mpeg2_info_t  *p_info;
  51     bool                b_skip;
  52
  53     /*
  54      * Input properties
  55      */
  56     mtime_t          i_previous_pts;
  57     mtime_t          i_current_pts;
  58     mtime_t          i_previous_dts;
  59     mtime_t          i_current_dts;
  60     picture_t *      p_picture_to_destroy;
  61     bool             b_garbage_pic;
  62     bool             b_after_sequence_header; /* is it the next frame after
  63                                                * the sequence header ?    */
  64     bool             b_slice_i;             /* intra-slice refresh stream */
  65     bool             b_second_field;
  66
  67     bool             b_preroll;
  68
  69     /*
  70      * Output properties
  71      */
  72     decoder_synchro_t *p_synchro;
  73     int            i_aspect;
  74     int            i_sar_num;
  75     int            i_sar_den;
  76     mtime_t        i_last_frame_pts;
  77
  78 };
  79
  80 /*****************************************************************************
  81  * Local prototypes
  82  *****************************************************************************/
  83 static int  OpenDecoder( vlc_object_t * );
  84 static void CloseDecoder( vlc_object_t * );
  85
  86 static picture_t *DecodeBlock( decoder_t *, block_t ** );
  87
  88 static picture_t *GetNewPicture( decoder_t *, uint8_t ** );
  89 static void GetAR( decoder_t *p_dec );
  90
  91 /*****************************************************************************
  92  * Module descriptor
  93  *****************************************************************************/
  94 vlc_module_begin();
  95     set_description( N_("MPEG I/II video decoder (using libmpeg2)") );
  96     set_capability( "decoder", 150 );
  97     set_category( CAT_INPUT );
  98     set_subcategory( SUBCAT_INPUT_VCODEC );
  99     set_callbacks( OpenDecoder, CloseDecoder );
 100     add_shortcut( "libmpeg2" );
 101 vlc_module_end();
 102
 103 /*****************************************************************************
 104  * OpenDecoder: probe the decoder and return score
 105  *****************************************************************************/
 106 static int OpenDecoder( vlc_object_t *p_this )
 107 {
 108     decoder_t *p_dec = (decoder_t*)p_this;
 109     decoder_sys_t *p_sys;
 110     uint32_t i_accel = 0;
 111
 112     if( p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','v') &&
 113         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','1') &&
 114         /* Pinnacle hardware-mpeg1 */
 115         p_dec->fmt_in.i_codec != VLC_FOURCC('P','I','M','1') &&
 116         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','2','v') &&
 117         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','2') &&
 118         p_dec->fmt_in.i_codec != VLC_FOURCC('h','d','v','2') )
 119     {
 120         return VLC_EGENERIC;
 121     }
 122
 123     /* Allocate the memory needed to store the decoder's structure */
 124     if( ( p_dec->p_sys = p_sys =
 125           (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
 126         return VLC_ENOMEM;
 127
 128     /* Initialize the thread properties */
 129     memset( p_sys, 0, sizeof(decoder_sys_t) );
 130     p_sys->p_mpeg2dec = NULL;
 131     p_sys->p_synchro  = NULL;
 132     p_sys->p_info     = NULL;
 133     p_sys->i_current_pts  = 0;
 134     p_sys->i_previous_pts = 0;
 135     p_sys->i_current_dts  = 0;
 136     p_sys->i_previous_dts = 0;
 137     p_sys->p_picture_to_destroy = NULL;
 138     p_sys->b_garbage_pic = 0;
 139     p_sys->b_slice_i  = 0;
 140     p_sys->b_second_field = 0;
 141     p_sys->b_skip     = 0;
 142     p_sys->b_preroll = false;
 143
 144 #if defined( __i386__ ) || defined( __x86_64__ )
 145     if( vlc_CPU() & CPU_CAPABILITY_MMX )
 146     {
 147         i_accel |= MPEG2_ACCEL_X86_MMX;
 148     }
 149
 150     if( vlc_CPU() & CPU_CAPABILITY_3DNOW )
 151     {
 152         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 153     }
 154
 155     if( vlc_CPU() & CPU_CAPABILITY_MMXEXT )
 156     {
 157         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 158     }
 159
 160 #elif defined( __powerpc__ ) || defined( __ppc__ ) || defined( __ppc64__ )
 161     if( vlc_CPU() & CPU_CAPABILITY_ALTIVEC )
 162     {
 163         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
 164     }
 165
 166 #else
 167     /* If we do not know this CPU, trust libmpeg2's feature detection */
 168     i_accel = MPEG2_ACCEL_DETECT;
 169
 170 #endif
 171
 172     /* Set CPU acceleration features */
 173     mpeg2_accel( i_accel );
 174
 175     /* Initialize decoder */
 176     p_sys->p_mpeg2dec = mpeg2_init();
 177     if( p_sys->p_mpeg2dec == NULL)
 178     {
 179         msg_Err( p_dec, "mpeg2_init() failed" );
 180         free( p_sys );
 181         return VLC_EGENERIC;
 182     }
 183
 184     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
 185
 186     p_dec->pf_decode_video = DecodeBlock;
 187
 188     return VLC_SUCCESS;
 189 }
 190
 191 /*****************************************************************************
 192  * RunDecoder: the libmpeg2 decoder
 193  *****************************************************************************/
 194 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 195 {
 196     decoder_sys_t   *p_sys = p_dec->p_sys;
 197     mpeg2_state_t   state;
 198     picture_t       *p_pic;
 199
 200     block_t *p_block;
 201
 202     if( !pp_block || !*pp_block ) return NULL;
 203
 204     p_block = *pp_block;
 205
 206     while( 1 )
 207     {
 208         state = mpeg2_parse( p_sys->p_mpeg2dec );
 209
 210         switch( state )
 211         {
 212         case STATE_BUFFER:
 213             if( !p_block->i_buffer )
 214             {
 215                 block_Release( p_block );
 216                 return NULL;
 217             }
 218
 219             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
 220                                       | BLOCK_FLAG_CORRUPTED)) &&
 221                 p_sys->p_synchro &&
 222                 p_sys->p_info->sequence &&
 223                 p_sys->p_info->sequence->width != (unsigned)-1 )
 224             {
 225                 decoder_SynchroReset( p_sys->p_synchro );
 226                 if( p_sys->p_info->current_fbuf != NULL
 227                     && p_sys->p_info->current_fbuf->id != NULL )
 228                 {
 229                     p_sys->b_garbage_pic = 1;
 230                     p_pic = p_sys->p_info->current_fbuf->id;
 231                 }
 232                 else
 233                 {
 234                     uint8_t *buf[3];
 235                     buf[0] = buf[1] = buf[2] = NULL;
 236                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 237                     {
 238                         p_block->i_buffer = 0;
 239                         break;
 240                     }
 241                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 242                     mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 243                 }
 244                 p_sys->p_picture_to_destroy = p_pic;
 245
 246                 if ( p_sys->b_slice_i )
 247                 {
 248                     decoder_SynchroNewPicture( p_sys->p_synchro,
 249                         I_CODING_TYPE, 2, 0, 0,
 250                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 251                     decoder_SynchroDecode( p_sys->p_synchro );
 252                     decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 253                 }
 254             }
 255
 256             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
 257             {
 258                 p_sys->b_preroll = true;
 259             }
 260             else if( p_sys->b_preroll )
 261             {
 262                 p_sys->b_preroll = false;
 263                 /* Reset synchro */
 264                 decoder_SynchroReset( p_sys->p_synchro );
 265             }
 266
 267 #ifdef PIC_FLAG_PTS
 268             if( p_block->i_pts )
 269             {
 270                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 271
 272 #else /* New interface */
 273             if( p_block->i_pts || p_block->i_dts )
 274             {
 275                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
 276                                    (uint32_t)p_block->i_pts,
 277                                    (uint32_t)p_block->i_dts );
 278 #endif
 279                 p_sys->i_previous_pts = p_sys->i_current_pts;
 280                 p_sys->i_current_pts = p_block->i_pts;
 281                 p_sys->i_previous_dts = p_sys->i_current_dts;
 282                 p_sys->i_current_dts = p_block->i_dts;
 283             }
 284
 285             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 286                           p_block->p_buffer + p_block->i_buffer );
 287
 288             p_block->i_buffer = 0;
 289             break;
 290
 291 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
 292
 293         case STATE_SEQUENCE_MODIFIED:
 294             GetAR( p_dec );
 295             break;
 296 #endif
 297
 298         case STATE_SEQUENCE:
 299         {
 300             /* Initialize video output */
 301             uint8_t *buf[3];
 302             buf[0] = buf[1] = buf[2] = NULL;
 303
 304             GetAR( p_dec );
 305
 306             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 307
 308             /* Set the first 2 reference frames */
 309             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 310
 311             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 312             {
 313                 block_Release( p_block );
 314                 return NULL;
 315             }
 316
 317             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 318             mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 319
 320             /* This picture will never go through display_picture. */
 321             p_pic->date = 0;
 322
 323             /* For some reason, libmpeg2 will put this pic twice in
 324              * discard_picture. This can be considered a bug in libmpeg2. */
 325             p_dec->pf_picture_link( p_dec, p_pic );
 326
 327             if( p_sys->p_synchro )
 328             {
 329                 decoder_SynchroRelease( p_sys->p_synchro );
 330             }
 331             p_sys->p_synchro = decoder_SynchroInit( p_dec,
 332                 (uint32_t)((uint64_t)1001000000 * 27 /
 333                 p_sys->p_info->sequence->frame_period) );
 334             p_sys->b_after_sequence_header = 1;
 335         }
 336         break;
 337
 338         case STATE_PICTURE_2ND:
 339             p_sys->b_second_field = 1;
 340             break;
 341
 342         case STATE_PICTURE:
 343         {
 344             uint8_t *buf[3];
 345             mtime_t i_pts, i_dts;
 346             buf[0] = buf[1] = buf[2] = NULL;
 347
 348             if ( p_sys->b_after_sequence_header &&
 349                  ((p_sys->p_info->current_picture->flags &
 350                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
 351             {
 352                 /* Intra-slice refresh. Simulate a blank I picture. */
 353                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 354                 decoder_SynchroNewPicture( p_sys->p_synchro,
 355                     I_CODING_TYPE, 2, 0, 0,
 356                     p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 357                 decoder_SynchroDecode( p_sys->p_synchro );
 358                 decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 359                 p_sys->b_slice_i = 1;
 360             }
 361             p_sys->b_after_sequence_header = 0;
 362
 363 #ifdef PIC_FLAG_PTS
 364             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
 365                 ( ( p_sys->p_info->current_picture->pts ==
 366                     (uint32_t)p_sys->i_current_pts ) ?
 367                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 368             i_dts = 0;
 369
 370             /* Hack to handle demuxers which only have DTS timestamps */
 371             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 372             {
 373                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 374                     (p_sys->p_info->current_picture->flags &
 375                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 376                 {
 377                     i_pts = p_block->i_dts;
 378                 }
 379             }
 380             p_block->i_pts = p_block->i_dts = 0;
 381             /* End hack */
 382
 383 #else /* New interface */
 384
 385             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 386                 ( ( p_sys->p_info->current_picture->tag ==
 387                     (uint32_t)p_sys->i_current_pts ) ?
 388                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 389             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 390                 ( ( p_sys->p_info->current_picture->tag2 ==
 391                     (uint32_t)p_sys->i_current_dts ) ?
 392                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 393 #endif
 394
 395             /* If nb_fields == 1, it is a field picture, and it will be
 396              * followed by another field picture for which we won't call
 397              * decoder_SynchroNewPicture() because this would have other
 398              * problems, so we take it into account here.
 399              * This kind of sucks, but I didn't think better. --Meuuh
 400              */
 401             decoder_SynchroNewPicture( p_sys->p_synchro,
 402                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 403                 p_sys->p_info->current_picture->nb_fields == 1 ? 2 :
 404                 p_sys->p_info->current_picture->nb_fields, i_pts, i_dts,
 405                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 406
 407             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
 408                 !(p_sys->b_slice_i
 409                    && ((p_sys->p_info->current_picture->flags
 410                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
 411                    && !decoder_SynchroChoose( p_sys->p_synchro,
 412                               p_sys->p_info->current_picture->flags
 413                                 & PIC_MASK_CODING_TYPE,
 414                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
 415                               p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
 416             {
 417                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 418                 p_sys->b_skip = 1;
 419                 decoder_SynchroTrash( p_sys->p_synchro );
 420                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 421             }
 422             else
 423             {
 424                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 425                 p_sys->b_skip = 0;
 426                 decoder_SynchroDecode( p_sys->p_synchro );
 427
 428                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 429                 {
 430                     block_Release( p_block );
 431                     return NULL;
 432                 }
 433
 434                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 435         mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 436             }
 437         }
 438         break;
 439
 440         case STATE_END:
 441         case STATE_SLICE:
 442             p_pic = NULL;
 443             if( p_sys->p_info->display_fbuf
 444                 && p_sys->p_info->display_fbuf->id )
 445             {
 446                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 447
 448                 decoder_SynchroEnd( p_sys->p_synchro,
 449                             p_sys->p_info->display_picture->flags
 450                              & PIC_MASK_CODING_TYPE,
 451                             p_sys->b_garbage_pic );
 452                 p_sys->b_garbage_pic = 0;
 453
 454                 if( p_sys->p_picture_to_destroy != p_pic )
 455                 {
 456                     p_pic->date = decoder_SynchroDate( p_sys->p_synchro );
 457                 }
 458                 else
 459                 {
 460                     p_sys->p_picture_to_destroy = NULL;
 461                     p_pic->date = 0;
 462                 }
 463             }
 464
 465             if( p_sys->p_info->discard_fbuf &&
 466                 p_sys->p_info->discard_fbuf->id )
 467             {
 468                 p_dec->pf_picture_unlink( p_dec,
 469                                           p_sys->p_info->discard_fbuf->id );
 470             }
 471
 472             /* For still frames */
 473             if( state == STATE_END && p_pic ) p_pic->b_force = true;
 474
 475             if( p_pic )
 476             {
 477                 /* Avoid frames with identical timestamps.
 478                  * Especially needed for still frames in DVD menus. */
 479                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
 480                 p_sys->i_last_frame_pts = p_pic->date;
 481
 482                 return p_pic;
 483             }
 484
 485             break;
 486
 487         case STATE_INVALID:
 488         {
 489             uint8_t *buf[3];
 490             buf[0] = buf[1] = buf[2] = NULL;
 491
 492             msg_Warn( p_dec, "invalid picture encountered" );
 493             if ( ( p_sys->p_info->current_picture == NULL ) ||
 494                ( ( p_sys->p_info->current_picture->flags &
 495                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
 496             {
 497                 if( p_sys->p_synchro ) decoder_SynchroReset( p_sys->p_synchro );
 498             }
 499             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 500             p_sys->b_skip = 1;
 501
 502             if( p_sys->p_info->current_fbuf &&
 503                 p_sys->p_info->current_fbuf->id )
 504             {
 505                 p_sys->b_garbage_pic = 1;
 506                 p_pic = p_sys->p_info->current_fbuf->id;
 507             }
 508             else if( !p_sys->p_info->sequence )
 509             {
 510                 break;
 511             }
 512             else
 513             {
 514                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 515                     break;
 516                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 517                 mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 518             }
 519             p_sys->p_picture_to_destroy = p_pic;
 520
 521             memset( p_pic->p[0].p_pixels, 0,
 522                     p_sys->p_info->sequence->width
 523                      * p_sys->p_info->sequence->height );
 524             memset( p_pic->p[1].p_pixels, 0x80,
 525                     p_sys->p_info->sequence->width
 526                      * p_sys->p_info->sequence->height / 4 );
 527             memset( p_pic->p[2].p_pixels, 0x80,
 528                     p_sys->p_info->sequence->width
 529                      * p_sys->p_info->sequence->height / 4 );
 530
 531             if( p_sys->b_slice_i )
 532             {
 533                 decoder_SynchroNewPicture( p_sys->p_synchro,
 534                         I_CODING_TYPE, 2, 0, 0,
 535                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 536                 decoder_SynchroDecode( p_sys->p_synchro );
 537                 decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 538             }
 539             break;
 540         }
 541
 542         default:
 543             break;
 544         }
 545     }
 546
 547     /* Never reached */
 548     return NULL;
 549 }
 550
 551 /*****************************************************************************
 552  * CloseDecoder: libmpeg2 decoder destruction
 553  *****************************************************************************/
 554 static void CloseDecoder( vlc_object_t *p_this )
 555 {
 556     decoder_t *p_dec = (decoder_t *)p_this;
 557     decoder_sys_t *p_sys = p_dec->p_sys;
 558
 559     if( p_sys->p_synchro ) decoder_SynchroRelease( p_sys->p_synchro );
 560
 561     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 562
 563     free( p_sys );
 564 }
 565
 566 /*****************************************************************************
 567  * GetNewPicture: Get a new picture from the vout and set the buf struct
 568  *****************************************************************************/
 569 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
 570 {
 571     decoder_sys_t *p_sys = p_dec->p_sys;
 572     picture_t *p_pic;
 573
 574     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
 575     p_dec->fmt_out.video.i_visible_width =
 576         p_sys->p_info->sequence->picture_width;
 577     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
 578     p_dec->fmt_out.video.i_visible_height =
 579         p_sys->p_info->sequence->picture_height;
 580     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
 581     p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
 582     p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;
 583
 584     if( p_sys->p_info->sequence->frame_period > 0 )
 585     {
 586         p_dec->fmt_out.video.i_frame_rate =
 587             (uint32_t)( (uint64_t)1001000000 * 27 /
 588                         p_sys->p_info->sequence->frame_period );
 589         p_dec->fmt_out.video.i_frame_rate_base = 1001;
 590     }
 591
 592     p_dec->fmt_out.i_codec =
 593         ( p_sys->p_info->sequence->chroma_height <
 594           p_sys->p_info->sequence->height ) ?
 595         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
 596
 597     /* Get a new picture */
 598     p_pic = p_dec->pf_vout_buffer_new( p_dec );
 599
 600     if( p_pic == NULL ) return NULL;
 601
 602     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 603         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 604     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 605         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 606     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 607         p_sys->p_info->current_picture->nb_fields : 2;
 608
 609     p_dec->pf_picture_link( p_dec, p_pic );
 610
 611     pp_buf[0] = p_pic->p[0].p_pixels;
 612     pp_buf[1] = p_pic->p[1].p_pixels;
 613     pp_buf[2] = p_pic->p[2].p_pixels;
 614
 615     return p_pic;
 616 }
 617
 618 /*****************************************************************************
 619  * GetAR: Get aspect ratio
 620  *****************************************************************************/
 621 static void GetAR( decoder_t *p_dec )
 622 {
 623     decoder_sys_t *p_sys = p_dec->p_sys;
 624
 625     /* Check whether the input gave a particular aspect ratio */
 626     if( p_dec->fmt_in.video.i_aspect )
 627     {
 628         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 629     }
 630     else
 631     {
 632         /* Use the value provided in the MPEG sequence header */
 633         if( p_sys->p_info->sequence->pixel_height > 0 )
 634         {
 635             p_sys->i_aspect =
 636                 ((uint64_t)p_sys->p_info->sequence->picture_width) *
 637                 p_sys->p_info->sequence->pixel_width *
 638                 VOUT_ASPECT_FACTOR /
 639                 p_sys->p_info->sequence->picture_height /
 640                 p_sys->p_info->sequence->pixel_height;
 641             p_sys->i_sar_num = p_sys->p_info->sequence->pixel_width;
 642             p_sys->i_sar_den = p_sys->p_info->sequence->pixel_height;
 643         }
 644         else
 645         {
 646             /* Invalid aspect, assume 4:3.
 647              * This shouldn't happen and if it does it is a bug
 648              * in libmpeg2 (likely triggered by an invalid stream) */
 649             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 650             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
 651             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
 652         }
 653     }
 654
 655     msg_Dbg( p_dec, "%dx%d (display %d,%d), aspect %d, sar %i:%i, %u.%03u fps",
 656              p_sys->p_info->sequence->picture_width,
 657              p_sys->p_info->sequence->picture_height,
 658              p_sys->p_info->sequence->display_width,
 659              p_sys->p_info->sequence->display_height,
 660              p_sys->i_aspect, p_sys->i_sar_num, p_sys->i_sar_den,
 661              (uint32_t)((uint64_t)1001000000 * 27 /
 662                  p_sys->p_info->sequence->frame_period / 1001),
 663              (uint32_t)((uint64_t)1001000000 * 27 /
 664                  p_sys->p_info->sequence->frame_period % 1001) );
 665 }