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     int            i_sar_num;
  76     int            i_sar_den;
  77     mtime_t        i_last_frame_pts;
  78
  79 };
  80
  81 /*****************************************************************************
  82  * Local prototypes
  83  *****************************************************************************/
  84 static int  OpenDecoder( vlc_object_t * );
  85 static void CloseDecoder( vlc_object_t * );
  86
  87 static picture_t *DecodeBlock( decoder_t *, block_t ** );
  88
  89 static picture_t *GetNewPicture( decoder_t *, uint8_t ** );
  90 static void GetAR( decoder_t *p_dec );
  91
  92 /*****************************************************************************
  93  * Module descriptor
  94  *****************************************************************************/
  95 vlc_module_begin();
  96     set_description( _("MPEG I/II video decoder (using libmpeg2)") );
  97     set_capability( "decoder", 150 );
  98     set_category( CAT_INPUT );
  99     set_subcategory( SUBCAT_INPUT_VCODEC );
 100     set_callbacks( OpenDecoder, CloseDecoder );
 101     add_shortcut( "libmpeg2" );
 102 vlc_module_end();
 103
 104 /*****************************************************************************
 105  * OpenDecoder: probe the decoder and return score
 106  *****************************************************************************/
 107 static int OpenDecoder( vlc_object_t *p_this )
 108 {
 109     decoder_t *p_dec = (decoder_t*)p_this;
 110     decoder_sys_t *p_sys;
 111     uint32_t i_accel = 0;
 112
 113     if( p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','v') &&
 114         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','1') &&
 115         /* Pinnacle hardware-mpeg1 */
 116         p_dec->fmt_in.i_codec != VLC_FOURCC('P','I','M','1') &&
 117         /* ATI Video */
 118         p_dec->fmt_in.i_codec != VLC_FOURCC('V','C','R','2') &&
 119         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','2') &&
 120         p_dec->fmt_in.i_codec != VLC_FOURCC('h','d','v','2') )
 121     {
 122         return VLC_EGENERIC;
 123     }
 124
 125     /* Allocate the memory needed to store the decoder's structure */
 126     if( ( p_dec->p_sys = p_sys =
 127           (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
 128     {
 129         msg_Err( p_dec, "out of memory" );
 130         return VLC_EGENERIC;
 131     }
 132
 133     /* Initialize the thread properties */
 134     memset( p_sys, 0, sizeof(decoder_sys_t) );
 135     p_sys->p_mpeg2dec = NULL;
 136     p_sys->p_synchro  = NULL;
 137     p_sys->p_info     = NULL;
 138     p_sys->i_current_pts  = 0;
 139     p_sys->i_previous_pts = 0;
 140     p_sys->i_current_dts  = 0;
 141     p_sys->i_previous_dts = 0;
 142     p_sys->p_picture_to_destroy = NULL;
 143     p_sys->b_garbage_pic = 0;
 144     p_sys->b_slice_i  = 0;
 145     p_sys->b_skip     = 0;
 146     p_sys->b_preroll = VLC_FALSE;
 147
 148 #if defined( __i386__ ) || defined( __x86_64__ )
 149     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_MMX )
 150     {
 151         i_accel |= MPEG2_ACCEL_X86_MMX;
 152     }
 153
 154     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_3DNOW )
 155     {
 156         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 157     }
 158
 159     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_MMXEXT )
 160     {
 161         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 162     }
 163
 164 #elif defined( __powerpc__ ) || defined( SYS_DARWIN )
 165     if( p_dec->p_libvlc->i_cpu & CPU_CAPABILITY_ALTIVEC )
 166     {
 167         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
 168     }
 169
 170 #else
 171     /* If we do not know this CPU, trust libmpeg2's feature detection */
 172     i_accel = MPEG2_ACCEL_DETECT;
 173
 174 #endif
 175
 176     /* Set CPU acceleration features */
 177     mpeg2_accel( i_accel );
 178
 179     /* Initialize decoder */
 180     p_sys->p_mpeg2dec = mpeg2_init();
 181     if( p_sys->p_mpeg2dec == NULL)
 182     {
 183         msg_Err( p_dec, "mpeg2_init() failed" );
 184         free( p_sys );
 185         return VLC_EGENERIC;
 186     }
 187
 188     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
 189
 190     p_dec->pf_decode_video = DecodeBlock;
 191
 192     return VLC_SUCCESS;
 193 }
 194
 195 /*****************************************************************************
 196  * RunDecoder: the libmpeg2 decoder
 197  *****************************************************************************/
 198 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 199 {
 200     decoder_sys_t   *p_sys = p_dec->p_sys;
 201     mpeg2_state_t   state;
 202     picture_t       *p_pic;
 203
 204     block_t *p_block;
 205
 206     if( !pp_block || !*pp_block ) return NULL;
 207
 208     p_block = *pp_block;
 209
 210     while( 1 )
 211     {
 212         state = mpeg2_parse( p_sys->p_mpeg2dec );
 213
 214         switch( state )
 215         {
 216         case STATE_BUFFER:
 217             if( !p_block->i_buffer )
 218             {
 219                 block_Release( p_block );
 220                 return NULL;
 221             }
 222
 223             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
 224                                       | BLOCK_FLAG_CORRUPTED)) &&
 225                 p_sys->p_synchro &&
 226                 p_sys->p_info->sequence &&
 227                 p_sys->p_info->sequence->width != (unsigned)-1 )
 228             {
 229                 vout_SynchroReset( p_sys->p_synchro );
 230                 if( p_sys->p_info->current_fbuf != NULL
 231                     && p_sys->p_info->current_fbuf->id != NULL )
 232                 {
 233                     p_sys->b_garbage_pic = 1;
 234                     p_pic = p_sys->p_info->current_fbuf->id;
 235                 }
 236                 else
 237                 {
 238                     uint8_t *buf[3];
 239                     buf[0] = buf[1] = buf[2] = NULL;
 240                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 241                         break;
 242                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 243                 }
 244                 p_sys->p_picture_to_destroy = p_pic;
 245
 246                 if ( p_sys->b_slice_i )
 247                 {
 248                     vout_SynchroNewPicture( p_sys->p_synchro,
 249                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 250                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 251                     vout_SynchroDecode( p_sys->p_synchro );
 252                     vout_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 = VLC_TRUE;
 259             }
 260             else if( p_sys->b_preroll )
 261             {
 262                 p_sys->b_preroll = VLC_FALSE;
 263                 /* Reset synchro */
 264                 vout_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             p_sys->i_current_rate = p_block->i_rate;
 286
 287             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 288                           p_block->p_buffer + p_block->i_buffer );
 289
 290             p_block->i_buffer = 0;
 291             break;
 292
 293 #ifdef STATE_SEQUENCE_MODIFIED
 294         case STATE_SEQUENCE_MODIFIED:
 295             GetAR( p_dec );
 296             break;
 297 #endif
 298
 299         case STATE_SEQUENCE:
 300         {
 301             /* Initialize video output */
 302             uint8_t *buf[3];
 303             buf[0] = buf[1] = buf[2] = NULL;
 304
 305             GetAR( p_dec );
 306
 307             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 308
 309             /* Set the first 2 reference frames */
 310             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 311
 312             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 313             {
 314                 block_Release( p_block );
 315                 return NULL;
 316             }
 317
 318             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 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                 vout_SynchroRelease( p_sys->p_synchro );
 330             }
 331             p_sys->p_synchro = vout_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             vout_SynchroNewPicture( p_sys->p_synchro,
 340                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 341                 p_sys->p_info->current_picture->nb_fields,
 342                 0, 0, p_sys->i_current_rate,
 343                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 344
 345             if( p_sys->b_skip )
 346             {
 347                 vout_SynchroTrash( p_sys->p_synchro );
 348             }
 349             else
 350             {
 351                 vout_SynchroDecode( p_sys->p_synchro );
 352             }
 353             break;
 354
 355         case STATE_PICTURE:
 356         {
 357             uint8_t *buf[3];
 358             mtime_t i_pts, i_dts;
 359             buf[0] = buf[1] = buf[2] = NULL;
 360
 361             if ( p_sys->b_after_sequence_header &&
 362                  ((p_sys->p_info->current_picture->flags &
 363                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
 364             {
 365                 /* Intra-slice refresh. Simulate a blank I picture. */
 366                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 367                 vout_SynchroNewPicture( p_sys->p_synchro,
 368                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 369                     p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 370                 vout_SynchroDecode( p_sys->p_synchro );
 371                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 372                 p_sys->b_slice_i = 1;
 373             }
 374             p_sys->b_after_sequence_header = 0;
 375
 376 #ifdef PIC_FLAG_PTS
 377             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
 378                 ( ( p_sys->p_info->current_picture->pts ==
 379                     (uint32_t)p_sys->i_current_pts ) ?
 380                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 381             i_dts = 0;
 382
 383             /* Hack to handle demuxers which only have DTS timestamps */
 384             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 385             {
 386                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 387                     (p_sys->p_info->current_picture->flags &
 388                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 389                 {
 390                     i_pts = p_block->i_dts;
 391                 }
 392             }
 393             p_block->i_pts = p_block->i_dts = 0;
 394             /* End hack */
 395
 396 #else /* New interface */
 397
 398             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 399                 ( ( p_sys->p_info->current_picture->tag ==
 400                     (uint32_t)p_sys->i_current_pts ) ?
 401                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 402             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 403                 ( ( p_sys->p_info->current_picture->tag2 ==
 404                     (uint32_t)p_sys->i_current_dts ) ?
 405                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 406 #endif
 407
 408             vout_SynchroNewPicture( p_sys->p_synchro,
 409                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 410                 p_sys->p_info->current_picture->nb_fields, i_pts, i_dts,
 411                 p_sys->i_current_rate,
 412                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 413
 414             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
 415                 !(p_sys->b_slice_i
 416                    && ((p_sys->p_info->current_picture->flags
 417                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
 418                    && !vout_SynchroChoose( p_sys->p_synchro,
 419                               p_sys->p_info->current_picture->flags
 420                                 & PIC_MASK_CODING_TYPE,
 421                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
 422                               p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
 423             {
 424                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 425                 p_sys->b_skip = 1;
 426                 vout_SynchroTrash( p_sys->p_synchro );
 427                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 428             }
 429             else
 430             {
 431                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 432                 p_sys->b_skip = 0;
 433                 vout_SynchroDecode( p_sys->p_synchro );
 434
 435                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 436                 {
 437                     block_Release( p_block );
 438                     return NULL;
 439                 }
 440
 441                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 442             }
 443         }
 444         break;
 445
 446         case STATE_END:
 447         case STATE_SLICE:
 448             p_pic = NULL;
 449             if( p_sys->p_info->display_fbuf
 450                 && p_sys->p_info->display_fbuf->id )
 451             {
 452                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 453
 454                 vout_SynchroEnd( p_sys->p_synchro,
 455                             p_sys->p_info->display_picture->flags
 456                              & PIC_MASK_CODING_TYPE,
 457                             p_sys->b_garbage_pic );
 458                 p_sys->b_garbage_pic = 0;
 459
 460                 if ( p_sys->p_picture_to_destroy != p_pic )
 461                 {
 462                     p_pic->date = vout_SynchroDate( p_sys->p_synchro );
 463                 }
 464                 else
 465                 {
 466                     p_sys->p_picture_to_destroy = NULL;
 467                     p_pic->date = 0;
 468                 }
 469             }
 470
 471             if( p_sys->p_info->discard_fbuf &&
 472                 p_sys->p_info->discard_fbuf->id )
 473             {
 474                 p_dec->pf_picture_unlink( p_dec,
 475                                           p_sys->p_info->discard_fbuf->id );
 476             }
 477
 478             /* For still frames */
 479             if( state == STATE_END && p_pic ) p_pic->b_force = VLC_TRUE;
 480
 481             if( p_pic )
 482             {
 483                 /* Avoid frames with identical timestamps.
 484                  * Especially needed for still frames in DVD menus. */
 485                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
 486                 p_sys->i_last_frame_pts = p_pic->date;
 487
 488                 return p_pic;
 489             }
 490
 491             break;
 492
 493         case STATE_INVALID:
 494         {
 495             uint8_t *buf[3];
 496             buf[0] = buf[1] = buf[2] = NULL;
 497
 498             msg_Warn( p_dec, "invalid picture encountered" );
 499             if ( ( p_sys->p_info->current_picture == NULL ) ||
 500                ( ( p_sys->p_info->current_picture->flags &
 501                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
 502             {
 503                 if( p_sys->p_synchro ) vout_SynchroReset( p_sys->p_synchro );
 504             }
 505             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 506             p_sys->b_skip = 1;
 507
 508             if( p_sys->p_info->current_fbuf &&
 509                 p_sys->p_info->current_fbuf->id )
 510             {
 511                 p_sys->b_garbage_pic = 1;
 512                 p_pic = p_sys->p_info->current_fbuf->id;
 513             }
 514             else if( !p_sys->p_info->sequence )
 515             {
 516                 break;
 517             }
 518             else
 519             {
 520                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 521                     break;
 522                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 523             }
 524             p_sys->p_picture_to_destroy = p_pic;
 525
 526             memset( p_pic->p[0].p_pixels, 0,
 527                     p_sys->p_info->sequence->width
 528                      * p_sys->p_info->sequence->height );
 529             memset( p_pic->p[1].p_pixels, 0x80,
 530                     p_sys->p_info->sequence->width
 531                      * p_sys->p_info->sequence->height / 4 );
 532             memset( p_pic->p[2].p_pixels, 0x80,
 533                     p_sys->p_info->sequence->width
 534                      * p_sys->p_info->sequence->height / 4 );
 535
 536             if( p_sys->b_slice_i )
 537             {
 538                 vout_SynchroNewPicture( p_sys->p_synchro,
 539                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 540                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 541                 vout_SynchroDecode( p_sys->p_synchro );
 542                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 543             }
 544             break;
 545         }
 546
 547         default:
 548             break;
 549         }
 550     }
 551
 552     /* Never reached */
 553     return NULL;
 554 }
 555
 556 /*****************************************************************************
 557  * CloseDecoder: libmpeg2 decoder destruction
 558  *****************************************************************************/
 559 static void CloseDecoder( vlc_object_t *p_this )
 560 {
 561     decoder_t *p_dec = (decoder_t *)p_this;
 562     decoder_sys_t *p_sys = p_dec->p_sys;
 563
 564     if( p_sys->p_synchro ) vout_SynchroRelease( p_sys->p_synchro );
 565
 566     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 567
 568     free( p_sys );
 569 }
 570
 571 /*****************************************************************************
 572  * GetNewPicture: Get a new picture from the vout and set the buf struct
 573  *****************************************************************************/
 574 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
 575 {
 576     decoder_sys_t *p_sys = p_dec->p_sys;
 577     picture_t *p_pic;
 578
 579     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
 580     p_dec->fmt_out.video.i_visible_width =
 581         p_sys->p_info->sequence->picture_width;
 582     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
 583     p_dec->fmt_out.video.i_visible_height =
 584         p_sys->p_info->sequence->picture_height;
 585     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
 586     p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
 587     p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;
 588
 589     if( p_sys->p_info->sequence->frame_period > 0 )
 590     {
 591         p_dec->fmt_out.video.i_frame_rate =
 592             (uint32_t)( (uint64_t)1001000000 * 27 /
 593                         p_sys->p_info->sequence->frame_period );
 594         p_dec->fmt_out.video.i_frame_rate_base = 1001;
 595     }
 596
 597     p_dec->fmt_out.i_codec =
 598         ( p_sys->p_info->sequence->chroma_height <
 599           p_sys->p_info->sequence->height ) ?
 600         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
 601
 602     /* Get a new picture */
 603     p_pic = p_dec->pf_vout_buffer_new( p_dec );
 604
 605     if( p_pic == NULL ) return NULL;
 606
 607     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 608         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 609     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 610         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 611     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 612         p_sys->p_info->current_picture->nb_fields : 2;
 613
 614     p_dec->pf_picture_link( p_dec, p_pic );
 615
 616     pp_buf[0] = p_pic->p[0].p_pixels;
 617     pp_buf[1] = p_pic->p[1].p_pixels;
 618     pp_buf[2] = p_pic->p[2].p_pixels;
 619
 620     return p_pic;
 621 }
 622
 623 /*****************************************************************************
 624  * GetAR: Get aspect ratio
 625  *****************************************************************************/
 626 static void GetAR( decoder_t *p_dec )
 627 {
 628     decoder_sys_t   *p_sys = p_dec->p_sys;
 629
 630     /* Check whether the input gave a particular aspect ratio */
 631     if( p_dec->fmt_in.video.i_aspect )
 632     {
 633         /* AR is relative to width/height, not display_width/height */
 634         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 635         if( p_sys->i_aspect <= AR_221_1_PICTURE )
 636         switch( p_sys->i_aspect )
 637         {
 638         case AR_3_4_PICTURE:
 639             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 640             p_sys->i_sar_num = p_sys->p_info->sequence->height * 4;
 641             p_sys->i_sar_den = p_sys->p_info->sequence->width * 3;
 642             break;
 643         case AR_16_9_PICTURE:
 644             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 645             p_sys->i_sar_num = p_sys->p_info->sequence->height * 16;
 646             p_sys->i_sar_den = p_sys->p_info->sequence->width * 9;
 647             break;
 648         case AR_221_1_PICTURE:
 649             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 650             p_sys->i_sar_num = p_sys->p_info->sequence->height * 221;
 651             p_sys->i_sar_den = p_sys->p_info->sequence->width * 100;
 652             break;
 653         case AR_SQUARE_PICTURE:
 654             p_sys->i_aspect = VOUT_ASPECT_FACTOR *
 655                            p_sys->p_info->sequence->width /
 656                            p_sys->p_info->sequence->height;
 657             p_sys->i_sar_num = p_sys->i_sar_den = 1;
 658             break;
 659         }
 660     }
 661     else
 662     {
 663         /* Use the value provided in the MPEG sequence header */
 664         if( p_sys->p_info->sequence->pixel_height > 0 )
 665         {
 666             p_sys->i_aspect =
 667                 ((uint64_t)p_sys->p_info->sequence->display_width) *
 668                 p_sys->p_info->sequence->pixel_width *
 669                 VOUT_ASPECT_FACTOR /
 670                 p_sys->p_info->sequence->display_height /
 671                 p_sys->p_info->sequence->pixel_height;
 672             p_sys->i_sar_num = p_sys->p_info->sequence->pixel_width;
 673             p_sys->i_sar_den = p_sys->p_info->sequence->pixel_height;
 674         }
 675         else
 676         {
 677             /* Invalid aspect, assume 4:3.
 678              * This shouldn't happen and if it does it is a bug
 679              * in libmpeg2 (likely triggered by an invalid stream) */
 680             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 681             p_sys->i_sar_num = p_sys->p_info->sequence->display_height * 4;
 682             p_sys->i_sar_den = p_sys->p_info->sequence->display_width * 3;
 683         }
 684     }
 685
 686     msg_Dbg( p_dec, "%dx%d, aspect %d, sar %i:%i, %u.%03u fps",
 687              p_sys->p_info->sequence->display_width,
 688              p_sys->p_info->sequence->display_height,
 689              p_sys->i_aspect, p_sys->i_sar_num, p_sys->i_sar_den,
 690              (uint32_t)((uint64_t)1001000000 * 27 /
 691                  p_sys->p_info->sequence->frame_period / 1001),
 692              (uint32_t)((uint64_t)1001000000 * 27 /
 693                  p_sys->p_info->sequence->frame_period % 1001) );
 694 }