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 #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_4_3_PICTURE          2                        /* 4:3 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_global->i_cpu & CPU_CAPABILITY_MMX )
 150     {
 151         i_accel |= MPEG2_ACCEL_X86_MMX;
 152     }
 153
 154     if( p_dec->p_libvlc_global->i_cpu & CPU_CAPABILITY_3DNOW )
 155     {
 156         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 157     }
 158
 159     if( p_dec->p_libvlc_global->i_cpu & CPU_CAPABILITY_MMXEXT )
 160     {
 161         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 162     }
 163
 164 #elif defined( __powerpc__ ) || defined( __ppc__ ) || defined( __ppc64__ )
 165     if( p_dec->p_libvlc_global->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                     mpeg2_stride( p_sys->p_mpeg2dec, p_pic->format.i_width );
 244                 }
 245                 p_sys->p_picture_to_destroy = p_pic;
 246
 247                 if ( p_sys->b_slice_i )
 248                 {
 249                     vout_SynchroNewPicture( p_sys->p_synchro,
 250                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 251                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 252                     vout_SynchroDecode( p_sys->p_synchro );
 253                     vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 254                 }
 255             }
 256
 257             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
 258             {
 259                 p_sys->b_preroll = VLC_TRUE;
 260             }
 261             else if( p_sys->b_preroll )
 262             {
 263                 p_sys->b_preroll = VLC_FALSE;
 264                 /* Reset synchro */
 265                 vout_SynchroReset( p_sys->p_synchro );
 266             }
 267
 268 #ifdef PIC_FLAG_PTS
 269             if( p_block->i_pts )
 270             {
 271                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 272
 273 #else /* New interface */
 274             if( p_block->i_pts || p_block->i_dts )
 275             {
 276                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
 277                                    (uint32_t)p_block->i_pts,
 278                                    (uint32_t)p_block->i_dts );
 279 #endif
 280                 p_sys->i_previous_pts = p_sys->i_current_pts;
 281                 p_sys->i_current_pts = p_block->i_pts;
 282                 p_sys->i_previous_dts = p_sys->i_current_dts;
 283                 p_sys->i_current_dts = p_block->i_dts;
 284             }
 285
 286             p_sys->i_current_rate = p_block->i_rate;
 287
 288             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 289                           p_block->p_buffer + p_block->i_buffer );
 290
 291             p_block->i_buffer = 0;
 292             break;
 293
 294 #ifdef STATE_SEQUENCE_MODIFIED
 295         case STATE_SEQUENCE_MODIFIED:
 296             GetAR( p_dec );
 297             break;
 298 #endif
 299
 300         case STATE_SEQUENCE:
 301         {
 302             /* Initialize video output */
 303             uint8_t *buf[3];
 304             buf[0] = buf[1] = buf[2] = NULL;
 305
 306             GetAR( p_dec );
 307
 308             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 309
 310             /* Set the first 2 reference frames */
 311             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 312
 313             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 314             {
 315                 block_Release( p_block );
 316                 return NULL;
 317             }
 318
 319             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 320             mpeg2_stride( p_sys->p_mpeg2dec, p_pic->format.i_width );
 321
 322             /* This picture will never go through display_picture. */
 323             p_pic->date = 0;
 324
 325             /* For some reason, libmpeg2 will put this pic twice in
 326              * discard_picture. This can be considered a bug in libmpeg2. */
 327             p_dec->pf_picture_link( p_dec, p_pic );
 328
 329             if( p_sys->p_synchro )
 330             {
 331                 vout_SynchroRelease( p_sys->p_synchro );
 332             }
 333             p_sys->p_synchro = vout_SynchroInit( p_dec,
 334                 (uint32_t)((uint64_t)1001000000 * 27 /
 335                 p_sys->p_info->sequence->frame_period) );
 336             p_sys->b_after_sequence_header = 1;
 337         }
 338         break;
 339
 340         case STATE_PICTURE_2ND:
 341             vout_SynchroNewPicture( p_sys->p_synchro,
 342                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 343                 p_sys->p_info->current_picture->nb_fields,
 344                 0, 0, p_sys->i_current_rate,
 345                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 346
 347             if( p_sys->b_skip )
 348             {
 349                 vout_SynchroTrash( p_sys->p_synchro );
 350             }
 351             else
 352             {
 353                 vout_SynchroDecode( p_sys->p_synchro );
 354             }
 355             break;
 356
 357         case STATE_PICTURE:
 358         {
 359             uint8_t *buf[3];
 360             mtime_t i_pts, i_dts;
 361             buf[0] = buf[1] = buf[2] = NULL;
 362
 363             if ( p_sys->b_after_sequence_header &&
 364                  ((p_sys->p_info->current_picture->flags &
 365                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
 366             {
 367                 /* Intra-slice refresh. Simulate a blank I picture. */
 368                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 369                 vout_SynchroNewPicture( p_sys->p_synchro,
 370                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 371                     p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 372                 vout_SynchroDecode( p_sys->p_synchro );
 373                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 374                 p_sys->b_slice_i = 1;
 375             }
 376             p_sys->b_after_sequence_header = 0;
 377
 378 #ifdef PIC_FLAG_PTS
 379             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
 380                 ( ( p_sys->p_info->current_picture->pts ==
 381                     (uint32_t)p_sys->i_current_pts ) ?
 382                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 383             i_dts = 0;
 384
 385             /* Hack to handle demuxers which only have DTS timestamps */
 386             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 387             {
 388                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 389                     (p_sys->p_info->current_picture->flags &
 390                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 391                 {
 392                     i_pts = p_block->i_dts;
 393                 }
 394             }
 395             p_block->i_pts = p_block->i_dts = 0;
 396             /* End hack */
 397
 398 #else /* New interface */
 399
 400             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 401                 ( ( p_sys->p_info->current_picture->tag ==
 402                     (uint32_t)p_sys->i_current_pts ) ?
 403                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 404             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 405                 ( ( p_sys->p_info->current_picture->tag2 ==
 406                     (uint32_t)p_sys->i_current_dts ) ?
 407                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 408 #endif
 409
 410             vout_SynchroNewPicture( p_sys->p_synchro,
 411                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 412                 p_sys->p_info->current_picture->nb_fields, i_pts, i_dts,
 413                 p_sys->i_current_rate,
 414                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 415
 416             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
 417                 !(p_sys->b_slice_i
 418                    && ((p_sys->p_info->current_picture->flags
 419                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
 420                    && !vout_SynchroChoose( p_sys->p_synchro,
 421                               p_sys->p_info->current_picture->flags
 422                                 & PIC_MASK_CODING_TYPE,
 423                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
 424                               p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
 425             {
 426                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 427                 p_sys->b_skip = 1;
 428                 vout_SynchroTrash( p_sys->p_synchro );
 429                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 430             }
 431             else
 432             {
 433                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 434                 p_sys->b_skip = 0;
 435                 vout_SynchroDecode( p_sys->p_synchro );
 436
 437                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 438                 {
 439                     block_Release( p_block );
 440                     return NULL;
 441                 }
 442
 443                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 444                 mpeg2_stride( p_sys->p_mpeg2dec, p_pic->format.i_width );
 445             }
 446         }
 447         break;
 448
 449         case STATE_END:
 450         case STATE_SLICE:
 451             p_pic = NULL;
 452             if( p_sys->p_info->display_fbuf
 453                 && p_sys->p_info->display_fbuf->id )
 454             {
 455                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 456
 457                 vout_SynchroEnd( p_sys->p_synchro,
 458                             p_sys->p_info->display_picture->flags
 459                              & PIC_MASK_CODING_TYPE,
 460                             p_sys->b_garbage_pic );
 461                 p_sys->b_garbage_pic = 0;
 462
 463                 if ( p_sys->p_picture_to_destroy != p_pic )
 464                 {
 465                     p_pic->date = vout_SynchroDate( p_sys->p_synchro );
 466                 }
 467                 else
 468                 {
 469                     p_sys->p_picture_to_destroy = NULL;
 470                     p_pic->date = 0;
 471                 }
 472             }
 473
 474             if( p_sys->p_info->discard_fbuf &&
 475                 p_sys->p_info->discard_fbuf->id )
 476             {
 477                 p_dec->pf_picture_unlink( p_dec,
 478                                           p_sys->p_info->discard_fbuf->id );
 479             }
 480
 481             /* For still frames */
 482             if( state == STATE_END && p_pic ) p_pic->b_force = VLC_TRUE;
 483
 484             if( p_pic )
 485             {
 486                 /* Avoid frames with identical timestamps.
 487                  * Especially needed for still frames in DVD menus. */
 488                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
 489                 p_sys->i_last_frame_pts = p_pic->date;
 490
 491                 return p_pic;
 492             }
 493
 494             break;
 495
 496         case STATE_INVALID:
 497         {
 498             uint8_t *buf[3];
 499             buf[0] = buf[1] = buf[2] = NULL;
 500
 501             msg_Warn( p_dec, "invalid picture encountered" );
 502             if ( ( p_sys->p_info->current_picture == NULL ) ||
 503                ( ( p_sys->p_info->current_picture->flags &
 504                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
 505             {
 506                 if( p_sys->p_synchro ) vout_SynchroReset( p_sys->p_synchro );
 507             }
 508             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 509             p_sys->b_skip = 1;
 510
 511             if( p_sys->p_info->current_fbuf &&
 512                 p_sys->p_info->current_fbuf->id )
 513             {
 514                 p_sys->b_garbage_pic = 1;
 515                 p_pic = p_sys->p_info->current_fbuf->id;
 516             }
 517             else if( !p_sys->p_info->sequence )
 518             {
 519                 break;
 520             }
 521             else
 522             {
 523                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 524                     break;
 525                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 526                 mpeg2_stride( p_sys->p_mpeg2dec, p_pic->format.i_width );
 527             }
 528             p_sys->p_picture_to_destroy = p_pic;
 529
 530             memset( p_pic->p[0].p_pixels, 0,
 531                     p_sys->p_info->sequence->width
 532                      * p_sys->p_info->sequence->height );
 533             memset( p_pic->p[1].p_pixels, 0x80,
 534                     p_sys->p_info->sequence->width
 535                      * p_sys->p_info->sequence->height / 4 );
 536             memset( p_pic->p[2].p_pixels, 0x80,
 537                     p_sys->p_info->sequence->width
 538                      * p_sys->p_info->sequence->height / 4 );
 539
 540             if( p_sys->b_slice_i )
 541             {
 542                 vout_SynchroNewPicture( p_sys->p_synchro,
 543                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 544                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 545                 vout_SynchroDecode( p_sys->p_synchro );
 546                 vout_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 547             }
 548             break;
 549         }
 550
 551         default:
 552             break;
 553         }
 554     }
 555
 556     /* Never reached */
 557     return NULL;
 558 }
 559
 560 /*****************************************************************************
 561  * CloseDecoder: libmpeg2 decoder destruction
 562  *****************************************************************************/
 563 static void CloseDecoder( vlc_object_t *p_this )
 564 {
 565     decoder_t *p_dec = (decoder_t *)p_this;
 566     decoder_sys_t *p_sys = p_dec->p_sys;
 567
 568     if( p_sys->p_synchro ) vout_SynchroRelease( p_sys->p_synchro );
 569
 570     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 571
 572     free( p_sys );
 573 }
 574
 575 /*****************************************************************************
 576  * GetNewPicture: Get a new picture from the vout and set the buf struct
 577  *****************************************************************************/
 578 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
 579 {
 580     decoder_sys_t *p_sys = p_dec->p_sys;
 581     picture_t *p_pic;
 582
 583     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
 584     p_dec->fmt_out.video.i_visible_width =
 585         p_sys->p_info->sequence->picture_width;
 586     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
 587     p_dec->fmt_out.video.i_visible_height =
 588         p_sys->p_info->sequence->picture_height;
 589     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
 590     p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
 591     p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;
 592
 593     if( p_sys->p_info->sequence->frame_period > 0 )
 594     {
 595         p_dec->fmt_out.video.i_frame_rate =
 596             (uint32_t)( (uint64_t)1001000000 * 27 /
 597                         p_sys->p_info->sequence->frame_period );
 598         p_dec->fmt_out.video.i_frame_rate_base = 1001;
 599     }
 600
 601     p_dec->fmt_out.i_codec =
 602         ( p_sys->p_info->sequence->chroma_height <
 603           p_sys->p_info->sequence->height ) ?
 604         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
 605
 606     /* Get a new picture */
 607     p_pic = p_dec->pf_vout_buffer_new( p_dec );
 608
 609     if( p_pic == NULL ) return NULL;
 610
 611     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 612         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 613     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 614         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 615     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 616         p_sys->p_info->current_picture->nb_fields : 2;
 617
 618     p_dec->pf_picture_link( p_dec, p_pic );
 619
 620     pp_buf[0] = p_pic->p[0].p_pixels;
 621     pp_buf[1] = p_pic->p[1].p_pixels;
 622     pp_buf[2] = p_pic->p[2].p_pixels;
 623
 624     return p_pic;
 625 }
 626
 627 /*****************************************************************************
 628  * GetAR: Get aspect ratio
 629  *****************************************************************************/
 630 static void GetAR( decoder_t *p_dec )
 631 {
 632     decoder_sys_t *p_sys = p_dec->p_sys;
 633
 634     /* Check whether the input gave a particular aspect ratio */
 635     if( p_dec->fmt_in.video.i_aspect )
 636     {
 637         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 638         if( p_sys->i_aspect <= AR_221_1_PICTURE )
 639         switch( p_sys->i_aspect )
 640         {
 641         case AR_4_3_PICTURE:
 642             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 643             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
 644             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
 645             break;
 646         case AR_16_9_PICTURE:
 647             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 648             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 16;
 649             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 9;
 650             break;
 651         case AR_221_1_PICTURE:
 652             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 653             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 221;
 654             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 100;
 655             break;
 656         case AR_SQUARE_PICTURE:
 657             p_sys->i_aspect = VOUT_ASPECT_FACTOR *
 658                            p_sys->p_info->sequence->picture_width /
 659                            p_sys->p_info->sequence->picture_height;
 660             p_sys->i_sar_num = p_sys->i_sar_den = 1;
 661             break;
 662         }
 663     }
 664     else
 665     {
 666         /* Use the value provided in the MPEG sequence header */
 667         if( p_sys->p_info->sequence->pixel_height > 0 )
 668         {
 669             p_sys->i_aspect =
 670                 ((uint64_t)p_sys->p_info->sequence->picture_width) *
 671                 p_sys->p_info->sequence->pixel_width *
 672                 VOUT_ASPECT_FACTOR /
 673                 p_sys->p_info->sequence->picture_height /
 674                 p_sys->p_info->sequence->pixel_height;
 675             p_sys->i_sar_num = p_sys->p_info->sequence->pixel_width;
 676             p_sys->i_sar_den = p_sys->p_info->sequence->pixel_height;
 677         }
 678         else
 679         {
 680             /* Invalid aspect, assume 4:3.
 681              * This shouldn't happen and if it does it is a bug
 682              * in libmpeg2 (likely triggered by an invalid stream) */
 683             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 684             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
 685             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
 686         }
 687     }
 688
 689     msg_Dbg( p_dec, "%dx%d (display %d,%d), aspect %d, sar %i:%i, %u.%03u fps",
 690              p_sys->p_info->sequence->picture_width,
 691              p_sys->p_info->sequence->picture_height,
 692              p_sys->p_info->sequence->display_width,
 693              p_sys->p_info->sequence->display_height,
 694              p_sys->i_aspect, p_sys->i_sar_num, p_sys->i_sar_den,
 695              (uint32_t)((uint64_t)1001000000 * 27 /
 696                  p_sys->p_info->sequence->frame_period / 1001),
 697              (uint32_t)((uint64_t)1001000000 * 27 /
 698                  p_sys->p_info->sequence->frame_period % 1001) );
 699 }