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     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     {
 119         return VLC_EGENERIC;
 120     }
 121
 122     /* Allocate the memory needed to store the decoder's structure */
 123     if( ( p_dec->p_sys = p_sys =
 124           (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
 125     {
 126         msg_Err( p_dec, "out of memory" );
 127         return VLC_EGENERIC;
 128     }
 129
 130     /* Initialize the thread properties */
 131     memset( p_sys, 0, sizeof(decoder_sys_t) );
 132     p_sys->p_mpeg2dec = NULL;
 133     p_sys->p_synchro  = NULL;
 134     p_sys->p_info     = NULL;
 135     p_sys->i_current_pts  = 0;
 136     p_sys->i_previous_pts = 0;
 137     p_sys->i_current_dts  = 0;
 138     p_sys->i_previous_dts = 0;
 139     p_sys->p_picture_to_destroy = NULL;
 140     p_sys->b_garbage_pic = 0;
 141     p_sys->b_slice_i  = 0;
 142     p_sys->b_skip     = 0;
 143     p_sys->b_preroll = VLC_FALSE;
 144
 145 #if defined( __i386__ ) || defined( __x86_64__ )
 146     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_MMX )
 147     {
 148         i_accel |= MPEG2_ACCEL_X86_MMX;
 149     }
 150
 151     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_3DNOW )
 152     {
 153         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 154     }
 155
 156     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_MMXEXT )
 157     {
 158         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 159     }
 160
 161 #elif defined( __powerpc__ ) || defined( SYS_DARWIN )
 162     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_ALTIVEC )
 163     {
 164         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
 165     }
 166
 167 #else
 168     /* If we do not know this CPU, trust libmpeg2's feature detection */
 169     i_accel = MPEG2_ACCEL_DETECT;
 170
 171 #endif
 172
 173     /* Set CPU acceleration features */
 174     mpeg2_accel( i_accel );
 175
 176     /* Initialize decoder */
 177     p_sys->p_mpeg2dec = mpeg2_init();
 178     if( p_sys->p_mpeg2dec == NULL)
 179     {
 180         msg_Err( p_dec, "mpeg2_init() failed" );
 181         free( p_sys );
 182         return VLC_EGENERIC;
 183     }
 184
 185     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
 186
 187     p_dec->pf_decode_video = DecodeBlock;
 188
 189     return VLC_SUCCESS;
 190 }
 191
 192 /*****************************************************************************
 193  * RunDecoder: the libmpeg2 decoder
 194  *****************************************************************************/
 195 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 196 {
 197     decoder_sys_t   *p_sys = p_dec->p_sys;
 198     mpeg2_state_t   state;
 199     picture_t       *p_pic;
 200
 201     block_t *p_block;
 202
 203     if( !pp_block || !*pp_block ) return NULL;
 204
 205     p_block = *pp_block;
 206
 207     while( 1 )
 208     {
 209         state = mpeg2_parse( p_sys->p_mpeg2dec );
 210
 211         switch( state )
 212         {
 213         case STATE_BUFFER:
 214             if( !p_block->i_buffer )
 215             {
 216                 block_Release( p_block );
 217                 return NULL;
 218             }
 219
 220             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
 221                                       | BLOCK_FLAG_CORRUPTED)) &&
 222                 p_sys->p_synchro &&
 223                 p_sys->p_info->sequence &&
 224                 p_sys->p_info->sequence->width != (unsigned)-1 )
 225             {
 226                 vout_SynchroReset( p_sys->p_synchro );
 227                 if( p_sys->p_info->current_fbuf != NULL
 228                     && p_sys->p_info->current_fbuf->id != NULL )
 229                 {
 230                     p_sys->b_garbage_pic = 1;
 231                     p_pic = p_sys->p_info->current_fbuf->id;
 232                 }
 233                 else
 234                 {
 235                     uint8_t *buf[3];
 236                     buf[0] = buf[1] = buf[2] = NULL;
 237                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 238                         break;
 239                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 240                 }
 241                 p_sys->p_picture_to_destroy = p_pic;
 242
 243                 if ( p_sys->b_slice_i )
 244                 {
 245                     vout_SynchroNewPicture( p_sys->p_synchro,
 246                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 247                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 248                     vout_SynchroDecode( p_sys->p_synchro );
 249                     vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 250                 }
 251             }
 252
 253             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
 254             {
 255                 p_sys->b_preroll = VLC_TRUE;
 256             }
 257             else if( p_sys->b_preroll )
 258             {
 259                 p_sys->b_preroll = VLC_FALSE;
 260                 /* Reset synchro */
 261                 vout_SynchroReset( p_sys->p_synchro );
 262             }
 263
 264 #ifdef PIC_FLAG_PTS
 265             if( p_block->i_pts )
 266             {
 267                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 268
 269 #else /* New interface */
 270             if( p_block->i_pts || p_block->i_dts )
 271             {
 272                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
 273                                    (uint32_t)p_block->i_pts,
 274                                    (uint32_t)p_block->i_dts );
 275 #endif
 276                 p_sys->i_previous_pts = p_sys->i_current_pts;
 277                 p_sys->i_current_pts = p_block->i_pts;
 278                 p_sys->i_previous_dts = p_sys->i_current_dts;
 279                 p_sys->i_current_dts = p_block->i_dts;
 280             }
 281
 282             p_sys->i_current_rate = p_block->i_rate;
 283
 284             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 285                           p_block->p_buffer + p_block->i_buffer );
 286
 287             p_block->i_buffer = 0;
 288             break;
 289
 290         case STATE_SEQUENCE_MODIFIED:
 291             GetAR( p_dec );
 292             break;
 293
 294         case STATE_SEQUENCE:
 295         {
 296             /* Initialize video output */
 297             uint8_t *buf[3];
 298             buf[0] = buf[1] = buf[2] = NULL;
 299
 300             GetAR( p_dec );
 301
 302             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 303
 304             /* Set the first 2 reference frames */
 305             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 306
 307             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 308             {
 309                 block_Release( p_block );
 310                 return NULL;
 311             }
 312
 313             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 314
 315             /* This picture will never go through display_picture. */
 316             p_pic->date = 0;
 317
 318             /* For some reason, libmpeg2 will put this pic twice in
 319              * discard_picture. This can be considered a bug in libmpeg2. */
 320             p_dec->pf_picture_link( p_dec, p_pic );
 321
 322             if( p_sys->p_synchro )
 323             {
 324                 vout_SynchroRelease( p_sys->p_synchro );
 325             }
 326             p_sys->p_synchro = vout_SynchroInit( p_dec,
 327                 (uint32_t)((uint64_t)1001000000 * 27 /
 328                 p_sys->p_info->sequence->frame_period) );
 329             p_sys->b_after_sequence_header = 1;
 330         }
 331         break;
 332
 333         case STATE_PICTURE_2ND:
 334             vout_SynchroNewPicture( p_sys->p_synchro,
 335                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 336                 p_sys->p_info->current_picture->nb_fields,
 337                 0, 0, p_sys->i_current_rate,
 338                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 339
 340             if( p_sys->b_skip )
 341             {
 342                 vout_SynchroTrash( p_sys->p_synchro );
 343             }
 344             else
 345             {
 346                 vout_SynchroDecode( p_sys->p_synchro );
 347             }
 348             break;
 349
 350         case STATE_PICTURE:
 351         {
 352             uint8_t *buf[3];
 353             mtime_t i_pts, i_dts;
 354             buf[0] = buf[1] = buf[2] = NULL;
 355
 356             if ( p_sys->b_after_sequence_header &&
 357                  ((p_sys->p_info->current_picture->flags &
 358                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
 359             {
 360                 /* Intra-slice refresh. Simulate a blank I picture. */
 361                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 362                 vout_SynchroNewPicture( p_sys->p_synchro,
 363                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 364                     p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 365                 vout_SynchroDecode( p_sys->p_synchro );
 366                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 367                 p_sys->b_slice_i = 1;
 368             }
 369             p_sys->b_after_sequence_header = 0;
 370
 371 #ifdef PIC_FLAG_PTS
 372             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
 373                 ( ( p_sys->p_info->current_picture->pts ==
 374                     (uint32_t)p_sys->i_current_pts ) ?
 375                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 376             i_dts = 0;
 377
 378             /* Hack to handle demuxers which only have DTS timestamps */
 379             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 380             {
 381                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 382                     (p_sys->p_info->current_picture->flags &
 383                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 384                 {
 385                     i_pts = p_block->i_dts;
 386                 }
 387             }
 388             p_block->i_pts = p_block->i_dts = 0;
 389             /* End hack */
 390
 391 #else /* New interface */
 392
 393             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 394                 ( ( p_sys->p_info->current_picture->tag ==
 395                     (uint32_t)p_sys->i_current_pts ) ?
 396                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 397             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 398                 ( ( p_sys->p_info->current_picture->tag2 ==
 399                     (uint32_t)p_sys->i_current_dts ) ?
 400                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 401 #endif
 402
 403             vout_SynchroNewPicture( p_sys->p_synchro,
 404                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 405                 p_sys->p_info->current_picture->nb_fields, i_pts, i_dts,
 406                 p_sys->i_current_rate,
 407                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 408
 409             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
 410                 !(p_sys->b_slice_i
 411                    && ((p_sys->p_info->current_picture->flags
 412                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
 413                    && !vout_SynchroChoose( p_sys->p_synchro,
 414                               p_sys->p_info->current_picture->flags
 415                                 & PIC_MASK_CODING_TYPE,
 416                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
 417                               p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
 418             {
 419                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 420                 p_sys->b_skip = 1;
 421                 vout_SynchroTrash( p_sys->p_synchro );
 422                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 423             }
 424             else
 425             {
 426                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 427                 p_sys->b_skip = 0;
 428                 vout_SynchroDecode( p_sys->p_synchro );
 429
 430                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 431                 {
 432                     block_Release( p_block );
 433                     return NULL;
 434                 }
 435
 436                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 437             }
 438         }
 439         break;
 440
 441         case STATE_END:
 442         case STATE_SLICE:
 443             p_pic = NULL;
 444             if( p_sys->p_info->display_fbuf
 445                 && p_sys->p_info->display_fbuf->id )
 446             {
 447                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 448
 449                 vout_SynchroEnd( p_sys->p_synchro,
 450                             p_sys->p_info->display_picture->flags
 451                              & PIC_MASK_CODING_TYPE,
 452                             p_sys->b_garbage_pic );
 453                 p_sys->b_garbage_pic = 0;
 454
 455                 if ( p_sys->p_picture_to_destroy != p_pic )
 456                 {
 457                     p_pic->date = vout_SynchroDate( p_sys->p_synchro );
 458                 }
 459                 else
 460                 {
 461                     p_sys->p_picture_to_destroy = NULL;
 462                     p_pic->date = 0;
 463                 }
 464             }
 465
 466             if( p_sys->p_info->discard_fbuf &&
 467                 p_sys->p_info->discard_fbuf->id )
 468             {
 469                 p_dec->pf_picture_unlink( p_dec,
 470                                           p_sys->p_info->discard_fbuf->id );
 471             }
 472
 473             /* For still frames */
 474             if( state == STATE_END && p_pic ) p_pic->b_force = VLC_TRUE;
 475
 476             if( p_pic )
 477             {
 478                 /* Avoid frames with identical timestamps.
 479                  * Especially needed for still frames in DVD menus. */
 480                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
 481                 p_sys->i_last_frame_pts = p_pic->date;
 482
 483                 return p_pic;
 484             }
 485
 486             break;
 487
 488         case STATE_INVALID:
 489         {
 490             uint8_t *buf[3];
 491             buf[0] = buf[1] = buf[2] = NULL;
 492
 493             msg_Warn( p_dec, "invalid picture encountered" );
 494             if ( ( p_sys->p_info->current_picture == NULL ) ||
 495                ( ( p_sys->p_info->current_picture->flags &
 496                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
 497             {
 498                 if( p_sys->p_synchro ) vout_SynchroReset( p_sys->p_synchro );
 499             }
 500             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 501             p_sys->b_skip = 1;
 502
 503             if( p_sys->p_info->current_fbuf &&
 504                 p_sys->p_info->current_fbuf->id )
 505             {
 506                 p_sys->b_garbage_pic = 1;
 507                 p_pic = p_sys->p_info->current_fbuf->id;
 508             }
 509             else if( !p_sys->p_info->sequence )
 510             {
 511                 break;
 512             }
 513             else
 514             {
 515                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 516                     break;
 517                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 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                 vout_SynchroNewPicture( p_sys->p_synchro,
 534                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 535                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 536                 vout_SynchroDecode( p_sys->p_synchro );
 537                 vout_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 ) vout_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
 582     if( p_sys->p_info->sequence->frame_period > 0 )
 583     {
 584         p_dec->fmt_out.video.i_frame_rate =
 585             (uint32_t)( (uint64_t)1001000000 * 27 /
 586                         p_sys->p_info->sequence->frame_period );
 587         p_dec->fmt_out.video.i_frame_rate_base = 1001;
 588     }
 589
 590     p_dec->fmt_out.i_codec =
 591         ( p_sys->p_info->sequence->chroma_height <
 592           p_sys->p_info->sequence->height ) ?
 593         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
 594
 595     /* Get a new picture */
 596     p_pic = p_dec->pf_vout_buffer_new( p_dec );
 597
 598     if( p_pic == NULL ) return NULL;
 599
 600     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 601         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 602     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 603         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 604     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 605         p_sys->p_info->current_picture->nb_fields : 2;
 606
 607     p_dec->pf_picture_link( p_dec, p_pic );
 608
 609     pp_buf[0] = p_pic->p[0].p_pixels;
 610     pp_buf[1] = p_pic->p[1].p_pixels;
 611     pp_buf[2] = p_pic->p[2].p_pixels;
 612
 613     return p_pic;
 614 }
 615
 616 /*****************************************************************************
 617  * GetAR: Get aspect ratio
 618  *****************************************************************************/
 619 static void GetAR( decoder_t *p_dec )
 620 {
 621     decoder_sys_t   *p_sys = p_dec->p_sys;
 622
 623     /* Check whether the input gave a particular aspect ratio */
 624     if( p_dec->fmt_in.video.i_aspect )
 625     {
 626         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 627         if( p_sys->i_aspect <= AR_221_1_PICTURE )
 628         switch( p_sys->i_aspect )
 629         {
 630         case AR_3_4_PICTURE:
 631             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 632             break;
 633         case AR_16_9_PICTURE:
 634             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 635             break;
 636         case AR_221_1_PICTURE:
 637             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 638             break;
 639         case AR_SQUARE_PICTURE:
 640             p_sys->i_aspect = VOUT_ASPECT_FACTOR *
 641                            p_sys->p_info->sequence->width /
 642                            p_sys->p_info->sequence->height;
 643             break;
 644         }
 645     }
 646     else
 647     {
 648         /* Use the value provided in the MPEG sequence header */
 649         if( p_sys->p_info->sequence->pixel_height > 0 )
 650         {
 651             p_sys->i_aspect =
 652                 ((uint64_t)p_sys->p_info->sequence->display_width) *
 653                 p_sys->p_info->sequence->pixel_width *
 654                 VOUT_ASPECT_FACTOR /
 655                 p_sys->p_info->sequence->display_height /
 656                 p_sys->p_info->sequence->pixel_height;
 657         }
 658         else
 659         {
 660             /* Invalid aspect, assume 4:3.
 661              * This shouldn't happen and if it does it is a bug
 662              * in libmpeg2 (likely triggered by an invalid stream) */
 663             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 664         }
 665     }
 666
 667     msg_Dbg( p_dec, "%dx%d, aspect %d, %u.%03u fps",
 668              p_sys->p_info->sequence->width,
 669              p_sys->p_info->sequence->height, p_sys->i_aspect,
 670              (uint32_t)((uint64_t)1001000000 * 27 /
 671                  p_sys->p_info->sequence->frame_period / 1001),
 672              (uint32_t)((uint64_t)1001000000 * 27 /
 673                  p_sys->p_info->sequence->frame_period % 1001) );
 674 }
 675