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., 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     vlc_bool_t      b_preroll;
  69
  70     /*
  71      * Output properties
  72      */
  73     vout_synchro_t *p_synchro;
  74     int            i_aspect;
  75     mtime_t        i_last_frame_pts;
  76
  77 };
  78
  79 /*****************************************************************************
  80  * Local prototypes
  81  *****************************************************************************/
  82 static int  OpenDecoder( vlc_object_t * );
  83 static void CloseDecoder( vlc_object_t * );
  84
  85 static picture_t *DecodeBlock( decoder_t *, block_t ** );
  86
  87 static picture_t *GetNewPicture( decoder_t *, uint8_t ** );
  88 static void GetAR( decoder_t *p_dec );
  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_category( CAT_INPUT );
  97     set_subcategory( SUBCAT_INPUT_VCODEC );
  98     set_callbacks( OpenDecoder, CloseDecoder );
  99     add_shortcut( "libmpeg2" );
 100 vlc_module_end();
 101
 102 /*****************************************************************************
 103  * OpenDecoder: probe the decoder and return score
 104  *****************************************************************************/
 105 static int OpenDecoder( vlc_object_t *p_this )
 106 {
 107     decoder_t *p_dec = (decoder_t*)p_this;
 108     decoder_sys_t *p_sys;
 109     uint32_t i_accel = 0;
 110
 111     if( p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','v') &&
 112         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','1') &&
 113         /* Pinnacle hardware-mpeg1 */
 114         p_dec->fmt_in.i_codec != VLC_FOURCC('P','I','M','1') &&
 115         /* ATI Video */
 116         p_dec->fmt_in.i_codec != VLC_FOURCC('V','C','R','2') &&
 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     {
 127         msg_Err( p_dec, "out of memory" );
 128         return VLC_EGENERIC;
 129     }
 130
 131     /* Initialize the thread properties */
 132     memset( p_sys, 0, sizeof(decoder_sys_t) );
 133     p_sys->p_mpeg2dec = NULL;
 134     p_sys->p_synchro  = NULL;
 135     p_sys->p_info     = NULL;
 136     p_sys->i_current_pts  = 0;
 137     p_sys->i_previous_pts = 0;
 138     p_sys->i_current_dts  = 0;
 139     p_sys->i_previous_dts = 0;
 140     p_sys->p_picture_to_destroy = NULL;
 141     p_sys->b_garbage_pic = 0;
 142     p_sys->b_slice_i  = 0;
 143     p_sys->b_skip     = 0;
 144     p_sys->b_preroll = VLC_FALSE;
 145
 146 #if defined( __i386__ ) || defined( __x86_64__ )
 147     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_MMX )
 148     {
 149         i_accel |= MPEG2_ACCEL_X86_MMX;
 150     }
 151
 152     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_3DNOW )
 153     {
 154         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 155     }
 156
 157     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_MMXEXT )
 158     {
 159         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 160     }
 161
 162 #elif defined( __powerpc__ ) || defined( SYS_DARWIN )
 163     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_ALTIVEC )
 164     {
 165         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
 166     }
 167
 168 #else
 169     /* If we do not know this CPU, trust libmpeg2's feature detection */
 170     i_accel = MPEG2_ACCEL_DETECT;
 171
 172 #endif
 173
 174     /* Set CPU acceleration features */
 175     mpeg2_accel( i_accel );
 176
 177     /* Initialize decoder */
 178     p_sys->p_mpeg2dec = mpeg2_init();
 179     if( p_sys->p_mpeg2dec == NULL)
 180     {
 181         msg_Err( p_dec, "mpeg2_init() failed" );
 182         free( p_sys );
 183         return VLC_EGENERIC;
 184     }
 185
 186     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
 187
 188     p_dec->pf_decode_video = DecodeBlock;
 189
 190     return VLC_SUCCESS;
 191 }
 192
 193 /*****************************************************************************
 194  * RunDecoder: the libmpeg2 decoder
 195  *****************************************************************************/
 196 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 197 {
 198     decoder_sys_t   *p_sys = p_dec->p_sys;
 199     mpeg2_state_t   state;
 200     picture_t       *p_pic;
 201
 202     block_t *p_block;
 203
 204     if( !pp_block || !*pp_block ) return NULL;
 205
 206     p_block = *pp_block;
 207
 208     while( 1 )
 209     {
 210         state = mpeg2_parse( p_sys->p_mpeg2dec );
 211
 212         switch( state )
 213         {
 214         case STATE_BUFFER:
 215             if( !p_block->i_buffer )
 216             {
 217                 block_Release( p_block );
 218                 return NULL;
 219             }
 220
 221             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
 222                                       | BLOCK_FLAG_CORRUPTED)) &&
 223                 p_sys->p_synchro &&
 224                 p_sys->p_info->sequence &&
 225                 p_sys->p_info->sequence->width != (unsigned)-1 )
 226             {
 227                 vout_SynchroReset( p_sys->p_synchro );
 228                 if( p_sys->p_info->current_fbuf != NULL
 229                     && p_sys->p_info->current_fbuf->id != NULL )
 230                 {
 231                     p_sys->b_garbage_pic = 1;
 232                     p_pic = p_sys->p_info->current_fbuf->id;
 233                 }
 234                 else
 235                 {
 236                     uint8_t *buf[3];
 237                     buf[0] = buf[1] = buf[2] = NULL;
 238                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 239                         break;
 240                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 241                 }
 242                 p_sys->p_picture_to_destroy = p_pic;
 243
 244                 if ( p_sys->b_slice_i )
 245                 {
 246                     vout_SynchroNewPicture( p_sys->p_synchro,
 247                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 248                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 249                     vout_SynchroDecode( p_sys->p_synchro );
 250                     vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 251                 }
 252             }
 253
 254             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
 255             {
 256                 p_sys->b_preroll = VLC_TRUE;
 257             }
 258             else if( p_sys->b_preroll )
 259             {
 260                 p_sys->b_preroll = VLC_FALSE;
 261                 /* Reset synchro */
 262                 vout_SynchroReset( p_sys->p_synchro );
 263             }
 264
 265 #ifdef PIC_FLAG_PTS
 266             if( p_block->i_pts )
 267             {
 268                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 269
 270 #else /* New interface */
 271             if( p_block->i_pts || p_block->i_dts )
 272             {
 273                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
 274                                    (uint32_t)p_block->i_pts,
 275                                    (uint32_t)p_block->i_dts );
 276 #endif
 277                 p_sys->i_previous_pts = p_sys->i_current_pts;
 278                 p_sys->i_current_pts = p_block->i_pts;
 279                 p_sys->i_previous_dts = p_sys->i_current_dts;
 280                 p_sys->i_current_dts = p_block->i_dts;
 281             }
 282
 283             p_sys->i_current_rate = p_block->i_rate;
 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 #ifdef STATE_SEQUENCE_MODIFIED
 292         case STATE_SEQUENCE_MODIFIED:
 293             GetAR( p_dec );
 294             break;
 295 #endif
 296
 297         case STATE_SEQUENCE:
 298         {
 299             /* Initialize video output */
 300             uint8_t *buf[3];
 301             buf[0] = buf[1] = buf[2] = NULL;
 302
 303             GetAR( p_dec );
 304
 305             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 306
 307             /* Set the first 2 reference frames */
 308             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 309
 310             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 311             {
 312                 block_Release( p_block );
 313                 return NULL;
 314             }
 315
 316             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 317
 318             /* This picture will never go through display_picture. */
 319             p_pic->date = 0;
 320
 321             /* For some reason, libmpeg2 will put this pic twice in
 322              * discard_picture. This can be considered a bug in libmpeg2. */
 323             p_dec->pf_picture_link( p_dec, p_pic );
 324
 325             if( p_sys->p_synchro )
 326             {
 327                 vout_SynchroRelease( p_sys->p_synchro );
 328             }
 329             p_sys->p_synchro = vout_SynchroInit( p_dec,
 330                 (uint32_t)((uint64_t)1001000000 * 27 /
 331                 p_sys->p_info->sequence->frame_period) );
 332             p_sys->b_after_sequence_header = 1;
 333         }
 334         break;
 335
 336         case STATE_PICTURE_2ND:
 337             vout_SynchroNewPicture( p_sys->p_synchro,
 338                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 339                 p_sys->p_info->current_picture->nb_fields,
 340                 0, 0, p_sys->i_current_rate,
 341                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 342
 343             if( p_sys->b_skip )
 344             {
 345                 vout_SynchroTrash( p_sys->p_synchro );
 346             }
 347             else
 348             {
 349                 vout_SynchroDecode( p_sys->p_synchro );
 350             }
 351             break;
 352
 353         case STATE_PICTURE:
 354         {
 355             uint8_t *buf[3];
 356             mtime_t i_pts, i_dts;
 357             buf[0] = buf[1] = buf[2] = NULL;
 358
 359             if ( p_sys->b_after_sequence_header &&
 360                  ((p_sys->p_info->current_picture->flags &
 361                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
 362             {
 363                 /* Intra-slice refresh. Simulate a blank I picture. */
 364                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 365                 vout_SynchroNewPicture( p_sys->p_synchro,
 366                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 367                     p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 368                 vout_SynchroDecode( p_sys->p_synchro );
 369                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 370                 p_sys->b_slice_i = 1;
 371             }
 372             p_sys->b_after_sequence_header = 0;
 373
 374 #ifdef PIC_FLAG_PTS
 375             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
 376                 ( ( p_sys->p_info->current_picture->pts ==
 377                     (uint32_t)p_sys->i_current_pts ) ?
 378                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 379             i_dts = 0;
 380
 381             /* Hack to handle demuxers which only have DTS timestamps */
 382             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 383             {
 384                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 385                     (p_sys->p_info->current_picture->flags &
 386                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 387                 {
 388                     i_pts = p_block->i_dts;
 389                 }
 390             }
 391             p_block->i_pts = p_block->i_dts = 0;
 392             /* End hack */
 393
 394 #else /* New interface */
 395
 396             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 397                 ( ( p_sys->p_info->current_picture->tag ==
 398                     (uint32_t)p_sys->i_current_pts ) ?
 399                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 400             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 401                 ( ( p_sys->p_info->current_picture->tag2 ==
 402                     (uint32_t)p_sys->i_current_dts ) ?
 403                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 404 #endif
 405
 406             vout_SynchroNewPicture( p_sys->p_synchro,
 407                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 408                 p_sys->p_info->current_picture->nb_fields, i_pts, i_dts,
 409                 p_sys->i_current_rate,
 410                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 411
 412             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
 413                 !(p_sys->b_slice_i
 414                    && ((p_sys->p_info->current_picture->flags
 415                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
 416                    && !vout_SynchroChoose( p_sys->p_synchro,
 417                               p_sys->p_info->current_picture->flags
 418                                 & PIC_MASK_CODING_TYPE,
 419                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
 420                               p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
 421             {
 422                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 423                 p_sys->b_skip = 1;
 424                 vout_SynchroTrash( p_sys->p_synchro );
 425                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 426             }
 427             else
 428             {
 429                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 430                 p_sys->b_skip = 0;
 431                 vout_SynchroDecode( p_sys->p_synchro );
 432
 433                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 434                 {
 435                     block_Release( p_block );
 436                     return NULL;
 437                 }
 438
 439                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 440             }
 441         }
 442         break;
 443
 444         case STATE_END:
 445         case STATE_SLICE:
 446             p_pic = NULL;
 447             if( p_sys->p_info->display_fbuf
 448                 && p_sys->p_info->display_fbuf->id )
 449             {
 450                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 451
 452                 vout_SynchroEnd( p_sys->p_synchro,
 453                             p_sys->p_info->display_picture->flags
 454                              & PIC_MASK_CODING_TYPE,
 455                             p_sys->b_garbage_pic );
 456                 p_sys->b_garbage_pic = 0;
 457
 458                 if ( p_sys->p_picture_to_destroy != p_pic )
 459                 {
 460                     p_pic->date = vout_SynchroDate( p_sys->p_synchro );
 461                 }
 462                 else
 463                 {
 464                     p_sys->p_picture_to_destroy = NULL;
 465                     p_pic->date = 0;
 466                 }
 467             }
 468
 469             if( p_sys->p_info->discard_fbuf &&
 470                 p_sys->p_info->discard_fbuf->id )
 471             {
 472                 p_dec->pf_picture_unlink( p_dec,
 473                                           p_sys->p_info->discard_fbuf->id );
 474             }
 475
 476             /* For still frames */
 477             if( state == STATE_END && p_pic ) p_pic->b_force = VLC_TRUE;
 478
 479             if( p_pic )
 480             {
 481                 /* Avoid frames with identical timestamps.
 482                  * Especially needed for still frames in DVD menus. */
 483                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
 484                 p_sys->i_last_frame_pts = p_pic->date;
 485
 486                 return p_pic;
 487             }
 488
 489             break;
 490
 491         case STATE_INVALID:
 492         {
 493             uint8_t *buf[3];
 494             buf[0] = buf[1] = buf[2] = NULL;
 495
 496             msg_Warn( p_dec, "invalid picture encountered" );
 497             if ( ( p_sys->p_info->current_picture == NULL ) ||
 498                ( ( p_sys->p_info->current_picture->flags &
 499                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
 500             {
 501                 if( p_sys->p_synchro ) vout_SynchroReset( p_sys->p_synchro );
 502             }
 503             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 504             p_sys->b_skip = 1;
 505
 506             if( p_sys->p_info->current_fbuf &&
 507                 p_sys->p_info->current_fbuf->id )
 508             {
 509                 p_sys->b_garbage_pic = 1;
 510                 p_pic = p_sys->p_info->current_fbuf->id;
 511             }
 512             else if( !p_sys->p_info->sequence )
 513             {
 514                 break;
 515             }
 516             else
 517             {
 518                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 519                     break;
 520                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 521             }
 522             p_sys->p_picture_to_destroy = p_pic;
 523
 524             memset( p_pic->p[0].p_pixels, 0,
 525                     p_sys->p_info->sequence->width
 526                      * p_sys->p_info->sequence->height );
 527             memset( p_pic->p[1].p_pixels, 0x80,
 528                     p_sys->p_info->sequence->width
 529                      * p_sys->p_info->sequence->height / 4 );
 530             memset( p_pic->p[2].p_pixels, 0x80,
 531                     p_sys->p_info->sequence->width
 532                      * p_sys->p_info->sequence->height / 4 );
 533
 534             if( p_sys->b_slice_i )
 535             {
 536                 vout_SynchroNewPicture( p_sys->p_synchro,
 537                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 538                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 539                 vout_SynchroDecode( p_sys->p_synchro );
 540                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 541             }
 542             break;
 543         }
 544
 545         default:
 546             break;
 547         }
 548     }
 549
 550     /* Never reached */
 551     return NULL;
 552 }
 553
 554 /*****************************************************************************
 555  * CloseDecoder: libmpeg2 decoder destruction
 556  *****************************************************************************/
 557 static void CloseDecoder( vlc_object_t *p_this )
 558 {
 559     decoder_t *p_dec = (decoder_t *)p_this;
 560     decoder_sys_t *p_sys = p_dec->p_sys;
 561
 562     if( p_sys->p_synchro ) vout_SynchroRelease( p_sys->p_synchro );
 563
 564     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 565
 566     free( p_sys );
 567 }
 568
 569 /*****************************************************************************
 570  * GetNewPicture: Get a new picture from the vout and set the buf struct
 571  *****************************************************************************/
 572 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
 573 {
 574     decoder_sys_t *p_sys = p_dec->p_sys;
 575     picture_t *p_pic;
 576
 577     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
 578     p_dec->fmt_out.video.i_visible_width =
 579         p_sys->p_info->sequence->picture_width;
 580     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
 581     p_dec->fmt_out.video.i_visible_height =
 582         p_sys->p_info->sequence->picture_height;
 583     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
 584
 585     if( p_sys->p_info->sequence->frame_period > 0 )
 586     {
 587         p_dec->fmt_out.video.i_frame_rate =
 588             (uint32_t)( (uint64_t)1001000000 * 27 /
 589                         p_sys->p_info->sequence->frame_period );
 590         p_dec->fmt_out.video.i_frame_rate_base = 1001;
 591     }
 592
 593     p_dec->fmt_out.i_codec =
 594         ( p_sys->p_info->sequence->chroma_height <
 595           p_sys->p_info->sequence->height ) ?
 596         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
 597
 598     /* Get a new picture */
 599     p_pic = p_dec->pf_vout_buffer_new( p_dec );
 600
 601     if( p_pic == NULL ) return NULL;
 602
 603     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 604         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 605     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 606         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 607     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 608         p_sys->p_info->current_picture->nb_fields : 2;
 609
 610     p_dec->pf_picture_link( p_dec, p_pic );
 611
 612     pp_buf[0] = p_pic->p[0].p_pixels;
 613     pp_buf[1] = p_pic->p[1].p_pixels;
 614     pp_buf[2] = p_pic->p[2].p_pixels;
 615
 616     return p_pic;
 617 }
 618
 619 /*****************************************************************************
 620  * GetAR: Get aspect ratio
 621  *****************************************************************************/
 622 static void GetAR( decoder_t *p_dec )
 623 {
 624     decoder_sys_t   *p_sys = p_dec->p_sys;
 625
 626     /* Check whether the input gave a particular aspect ratio */
 627     if( p_dec->fmt_in.video.i_aspect )
 628     {
 629         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 630         if( p_sys->i_aspect <= AR_221_1_PICTURE )
 631         switch( p_sys->i_aspect )
 632         {
 633         case AR_3_4_PICTURE:
 634             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 635             break;
 636         case AR_16_9_PICTURE:
 637             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 638             break;
 639         case AR_221_1_PICTURE:
 640             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 641             break;
 642         case AR_SQUARE_PICTURE:
 643             p_sys->i_aspect = VOUT_ASPECT_FACTOR *
 644                            p_sys->p_info->sequence->width /
 645                            p_sys->p_info->sequence->height;
 646             break;
 647         }
 648     }
 649     else
 650     {
 651         /* Use the value provided in the MPEG sequence header */
 652         if( p_sys->p_info->sequence->pixel_height > 0 )
 653         {
 654             p_sys->i_aspect =
 655                 ((uint64_t)p_sys->p_info->sequence->display_width) *
 656                 p_sys->p_info->sequence->pixel_width *
 657                 VOUT_ASPECT_FACTOR /
 658                 p_sys->p_info->sequence->display_height /
 659                 p_sys->p_info->sequence->pixel_height;
 660         }
 661         else
 662         {
 663             /* Invalid aspect, assume 4:3.
 664              * This shouldn't happen and if it does it is a bug
 665              * in libmpeg2 (likely triggered by an invalid stream) */
 666             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 667         }
 668     }
 669
 670     msg_Dbg( p_dec, "%dx%d, aspect %d, %u.%03u fps",
 671              p_sys->p_info->sequence->display_width,
 672              p_sys->p_info->sequence->display_height, p_sys->i_aspect,
 673              (uint32_t)((uint64_t)1001000000 * 27 /
 674                  p_sys->p_info->sequence->frame_period / 1001),
 675              (uint32_t)((uint64_t)1001000000 * 27 /
 676                  p_sys->p_info->sequence->frame_period % 1001) );
 677 }
 678