git.sesse.net Git - vlc/blob - modules/codec/libmpeg2.c

   1 /*****************************************************************************
   2  * libmpeg2.c: mpeg2 video decoder module making use of libmpeg2.
   3  *****************************************************************************
   4  * Copyright (C) 1999-2001 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@videolan.org>
   8  *          Christophe Massiot <massiot@via.ecp.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_vout.h>
  35 #include <vlc_codec.h>
  36
  37 #include <mpeg2.h>
  38
  39 #include <vlc_codec_synchro.h>
  40
  41 /* Aspect ratio (ISO/IEC 13818-2 section 6.3.3, table 6-3) */
  42 #define AR_SQUARE_PICTURE       1                           /* square pixels */
  43 #define AR_4_3_PICTURE          2                        /* 4:3 picture (TV) */
  44 #define AR_16_9_PICTURE         3              /* 16:9 picture (wide screen) */
  45 #define AR_221_1_PICTURE        4                  /* 2.21:1 picture (movie) */
  46
  47 /*****************************************************************************
  48  * decoder_sys_t : libmpeg2 decoder descriptor
  49  *****************************************************************************/
  50 struct decoder_sys_t
  51 {
  52     /*
  53      * libmpeg2 properties
  54      */
  55     mpeg2dec_t          *p_mpeg2dec;
  56     const mpeg2_info_t  *p_info;
  57     bool                b_skip;
  58
  59     /*
  60      * Input properties
  61      */
  62     mtime_t          i_previous_pts;
  63     mtime_t          i_current_pts;
  64     mtime_t          i_previous_dts;
  65     mtime_t          i_current_dts;
  66     int              i_current_rate;
  67     picture_t *      p_picture_to_destroy;
  68     bool             b_garbage_pic;
  69     bool             b_after_sequence_header; /* is it the next frame after
  70                                                * the sequence header ?    */
  71     bool             b_slice_i;             /* intra-slice refresh stream */
  72     bool             b_second_field;
  73
  74     bool             b_preroll;
  75
  76     /*
  77      * Output properties
  78      */
  79     decoder_synchro_t *p_synchro;
  80     int            i_aspect;
  81     int            i_sar_num;
  82     int            i_sar_den;
  83     mtime_t        i_last_frame_pts;
  84
  85 };
  86
  87 /*****************************************************************************
  88  * Local prototypes
  89  *****************************************************************************/
  90 static int  OpenDecoder( vlc_object_t * );
  91 static void CloseDecoder( vlc_object_t * );
  92
  93 static picture_t *DecodeBlock( decoder_t *, block_t ** );
  94
  95 static picture_t *GetNewPicture( decoder_t *, uint8_t ** );
  96 static void GetAR( decoder_t *p_dec );
  97
  98 /*****************************************************************************
  99  * Module descriptor
 100  *****************************************************************************/
 101 vlc_module_begin();
 102     set_description( N_("MPEG I/II video decoder (using libmpeg2)") );
 103     set_capability( "decoder", 150 );
 104     set_category( CAT_INPUT );
 105     set_subcategory( SUBCAT_INPUT_VCODEC );
 106     set_callbacks( OpenDecoder, CloseDecoder );
 107     add_shortcut( "libmpeg2" );
 108 vlc_module_end();
 109
 110 /*****************************************************************************
 111  * OpenDecoder: probe the decoder and return score
 112  *****************************************************************************/
 113 static int OpenDecoder( vlc_object_t *p_this )
 114 {
 115     decoder_t *p_dec = (decoder_t*)p_this;
 116     decoder_sys_t *p_sys;
 117     uint32_t i_accel = 0;
 118
 119     if( p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','v') &&
 120         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','1') &&
 121         /* Pinnacle hardware-mpeg1 */
 122         p_dec->fmt_in.i_codec != VLC_FOURCC('P','I','M','1') &&
 123         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','2','v') &&
 124         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','2') &&
 125         p_dec->fmt_in.i_codec != VLC_FOURCC('h','d','v','2') )
 126     {
 127         return VLC_EGENERIC;
 128     }
 129
 130     /* Allocate the memory needed to store the decoder's structure */
 131     if( ( p_dec->p_sys = p_sys =
 132           (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
 133         return VLC_ENOMEM;
 134
 135     /* Initialize the thread properties */
 136     memset( p_sys, 0, sizeof(decoder_sys_t) );
 137     p_sys->p_mpeg2dec = NULL;
 138     p_sys->p_synchro  = NULL;
 139     p_sys->p_info     = NULL;
 140     p_sys->i_current_pts  = 0;
 141     p_sys->i_previous_pts = 0;
 142     p_sys->i_current_dts  = 0;
 143     p_sys->i_previous_dts = 0;
 144     p_sys->p_picture_to_destroy = NULL;
 145     p_sys->b_garbage_pic = 0;
 146     p_sys->b_slice_i  = 0;
 147     p_sys->b_second_field = 0;
 148     p_sys->b_skip     = 0;
 149     p_sys->b_preroll = false;
 150
 151 #if defined( __i386__ ) || defined( __x86_64__ )
 152     if( vlc_CPU() & CPU_CAPABILITY_MMX )
 153     {
 154         i_accel |= MPEG2_ACCEL_X86_MMX;
 155     }
 156
 157     if( vlc_CPU() & CPU_CAPABILITY_3DNOW )
 158     {
 159         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 160     }
 161
 162     if( vlc_CPU() & CPU_CAPABILITY_MMXEXT )
 163     {
 164         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 165     }
 166
 167 #elif defined( __powerpc__ ) || defined( __ppc__ ) || defined( __ppc64__ )
 168     if( vlc_CPU() & CPU_CAPABILITY_ALTIVEC )
 169     {
 170         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
 171     }
 172
 173 #else
 174     /* If we do not know this CPU, trust libmpeg2's feature detection */
 175     i_accel = MPEG2_ACCEL_DETECT;
 176
 177 #endif
 178
 179     /* Set CPU acceleration features */
 180     mpeg2_accel( i_accel );
 181
 182     /* Initialize decoder */
 183     p_sys->p_mpeg2dec = mpeg2_init();
 184     if( p_sys->p_mpeg2dec == NULL)
 185     {
 186         msg_Err( p_dec, "mpeg2_init() failed" );
 187         free( p_sys );
 188         return VLC_EGENERIC;
 189     }
 190
 191     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
 192
 193     p_dec->pf_decode_video = DecodeBlock;
 194
 195     return VLC_SUCCESS;
 196 }
 197
 198 /*****************************************************************************
 199  * RunDecoder: the libmpeg2 decoder
 200  *****************************************************************************/
 201 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 202 {
 203     decoder_sys_t   *p_sys = p_dec->p_sys;
 204     mpeg2_state_t   state;
 205     picture_t       *p_pic;
 206
 207     block_t *p_block;
 208
 209     if( !pp_block || !*pp_block ) return NULL;
 210
 211     p_block = *pp_block;
 212
 213     while( 1 )
 214     {
 215         state = mpeg2_parse( p_sys->p_mpeg2dec );
 216
 217         switch( state )
 218         {
 219         case STATE_BUFFER:
 220             if( !p_block->i_buffer )
 221             {
 222                 block_Release( p_block );
 223                 return NULL;
 224             }
 225
 226             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
 227                                       | BLOCK_FLAG_CORRUPTED)) &&
 228                 p_sys->p_synchro &&
 229                 p_sys->p_info->sequence &&
 230                 p_sys->p_info->sequence->width != (unsigned)-1 )
 231             {
 232                 decoder_SynchroReset( p_sys->p_synchro );
 233                 if( p_sys->p_info->current_fbuf != NULL
 234                     && p_sys->p_info->current_fbuf->id != NULL )
 235                 {
 236                     p_sys->b_garbage_pic = 1;
 237                     p_pic = p_sys->p_info->current_fbuf->id;
 238                 }
 239                 else
 240                 {
 241                     uint8_t *buf[3];
 242                     buf[0] = buf[1] = buf[2] = NULL;
 243                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 244                         break;
 245                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 246                     mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 247                 }
 248                 p_sys->p_picture_to_destroy = p_pic;
 249
 250                 if ( p_sys->b_slice_i )
 251                 {
 252                     decoder_SynchroNewPicture( p_sys->p_synchro,
 253                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 254                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 255                     decoder_SynchroDecode( p_sys->p_synchro );
 256                     decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 257                 }
 258             }
 259
 260             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
 261             {
 262                 p_sys->b_preroll = true;
 263             }
 264             else if( p_sys->b_preroll )
 265             {
 266                 p_sys->b_preroll = false;
 267                 /* Reset synchro */
 268                 decoder_SynchroReset( p_sys->p_synchro );
 269             }
 270
 271 #ifdef PIC_FLAG_PTS
 272             if( p_block->i_pts )
 273             {
 274                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 275
 276 #else /* New interface */
 277             if( p_block->i_pts || p_block->i_dts )
 278             {
 279                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
 280                                    (uint32_t)p_block->i_pts,
 281                                    (uint32_t)p_block->i_dts );
 282 #endif
 283                 p_sys->i_previous_pts = p_sys->i_current_pts;
 284                 p_sys->i_current_pts = p_block->i_pts;
 285                 p_sys->i_previous_dts = p_sys->i_current_dts;
 286                 p_sys->i_current_dts = p_block->i_dts;
 287             }
 288
 289             p_sys->i_current_rate = p_block->i_rate;
 290
 291             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 292                           p_block->p_buffer + p_block->i_buffer );
 293
 294             p_block->i_buffer = 0;
 295             break;
 296
 297 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
 298
 299         case STATE_SEQUENCE_MODIFIED:
 300             GetAR( p_dec );
 301             break;
 302 #endif
 303
 304         case STATE_SEQUENCE:
 305         {
 306             /* Initialize video output */
 307             uint8_t *buf[3];
 308             buf[0] = buf[1] = buf[2] = NULL;
 309
 310             GetAR( p_dec );
 311
 312             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 313
 314             /* Set the first 2 reference frames */
 315             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 316
 317             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 318             {
 319                 block_Release( p_block );
 320                 return NULL;
 321             }
 322
 323             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 324             mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 325
 326             /* This picture will never go through display_picture. */
 327             p_pic->date = 0;
 328
 329             /* For some reason, libmpeg2 will put this pic twice in
 330              * discard_picture. This can be considered a bug in libmpeg2. */
 331             p_dec->pf_picture_link( p_dec, p_pic );
 332
 333             if( p_sys->p_synchro )
 334             {
 335                 decoder_SynchroRelease( p_sys->p_synchro );
 336             }
 337             p_sys->p_synchro = decoder_SynchroInit( p_dec,
 338                 (uint32_t)((uint64_t)1001000000 * 27 /
 339                 p_sys->p_info->sequence->frame_period) );
 340             p_sys->b_after_sequence_header = 1;
 341         }
 342         break;
 343
 344         case STATE_PICTURE_2ND:
 345             p_sys->b_second_field = 1;
 346             break;
 347
 348         case STATE_PICTURE:
 349         {
 350             uint8_t *buf[3];
 351             mtime_t i_pts, i_dts;
 352             buf[0] = buf[1] = buf[2] = NULL;
 353
 354             if ( p_sys->b_after_sequence_header &&
 355                  ((p_sys->p_info->current_picture->flags &
 356                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
 357             {
 358                 /* Intra-slice refresh. Simulate a blank I picture. */
 359                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 360                 decoder_SynchroNewPicture( p_sys->p_synchro,
 361                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 362                     p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 363                 decoder_SynchroDecode( p_sys->p_synchro );
 364                 decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 365                 p_sys->b_slice_i = 1;
 366             }
 367             p_sys->b_after_sequence_header = 0;
 368
 369 #ifdef PIC_FLAG_PTS
 370             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
 371                 ( ( p_sys->p_info->current_picture->pts ==
 372                     (uint32_t)p_sys->i_current_pts ) ?
 373                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 374             i_dts = 0;
 375
 376             /* Hack to handle demuxers which only have DTS timestamps */
 377             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 378             {
 379                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 380                     (p_sys->p_info->current_picture->flags &
 381                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 382                 {
 383                     i_pts = p_block->i_dts;
 384                 }
 385             }
 386             p_block->i_pts = p_block->i_dts = 0;
 387             /* End hack */
 388
 389 #else /* New interface */
 390
 391             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 392                 ( ( p_sys->p_info->current_picture->tag ==
 393                     (uint32_t)p_sys->i_current_pts ) ?
 394                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 395             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 396                 ( ( p_sys->p_info->current_picture->tag2 ==
 397                     (uint32_t)p_sys->i_current_dts ) ?
 398                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 399 #endif
 400
 401             /* If nb_fields == 1, it is a field picture, and it will be
 402              * followed by another field picture for which we won't call
 403              * decoder_SynchroNewPicture() because this would have other
 404              * problems, so we take it into account here.
 405              * This kind of sucks, but I didn't think better. --Meuuh
 406              */
 407             decoder_SynchroNewPicture( p_sys->p_synchro,
 408                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 409                 p_sys->p_info->current_picture->nb_fields == 1 ? 2 :
 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                    && !decoder_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                 decoder_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                 decoder_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         mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 443             }
 444         }
 445         break;
 446
 447         case STATE_END:
 448         case STATE_SLICE:
 449             p_pic = NULL;
 450             if( p_sys->p_info->display_fbuf
 451                 && p_sys->p_info->display_fbuf->id )
 452             {
 453                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 454
 455                 decoder_SynchroEnd( p_sys->p_synchro,
 456                             p_sys->p_info->display_picture->flags
 457                              & PIC_MASK_CODING_TYPE,
 458                             p_sys->b_garbage_pic );
 459                 p_sys->b_garbage_pic = 0;
 460
 461                 if ( p_sys->p_picture_to_destroy != p_pic )
 462                 {
 463                     p_pic->date = decoder_SynchroDate( p_sys->p_synchro );
 464                 }
 465                 else
 466                 {
 467                     p_sys->p_picture_to_destroy = NULL;
 468                     p_pic->date = 0;
 469                 }
 470             }
 471
 472             if( p_sys->p_info->discard_fbuf &&
 473                 p_sys->p_info->discard_fbuf->id )
 474             {
 475                 p_dec->pf_picture_unlink( p_dec,
 476                                           p_sys->p_info->discard_fbuf->id );
 477             }
 478
 479             /* For still frames */
 480             if( state == STATE_END && p_pic ) p_pic->b_force = true;
 481
 482             if( p_pic )
 483             {
 484                 /* Avoid frames with identical timestamps.
 485                  * Especially needed for still frames in DVD menus. */
 486                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
 487                 p_sys->i_last_frame_pts = p_pic->date;
 488
 489                 return p_pic;
 490             }
 491
 492             break;
 493
 494         case STATE_INVALID:
 495         {
 496             uint8_t *buf[3];
 497             buf[0] = buf[1] = buf[2] = NULL;
 498
 499             msg_Warn( p_dec, "invalid picture encountered" );
 500             if ( ( p_sys->p_info->current_picture == NULL ) ||
 501                ( ( p_sys->p_info->current_picture->flags &
 502                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
 503             {
 504                 if( p_sys->p_synchro ) decoder_SynchroReset( p_sys->p_synchro );
 505             }
 506             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 507             p_sys->b_skip = 1;
 508
 509             if( p_sys->p_info->current_fbuf &&
 510                 p_sys->p_info->current_fbuf->id )
 511             {
 512                 p_sys->b_garbage_pic = 1;
 513                 p_pic = p_sys->p_info->current_fbuf->id;
 514             }
 515             else if( !p_sys->p_info->sequence )
 516             {
 517                 break;
 518             }
 519             else
 520             {
 521                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 522                     break;
 523                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 524                 mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 525             }
 526             p_sys->p_picture_to_destroy = p_pic;
 527
 528             memset( p_pic->p[0].p_pixels, 0,
 529                     p_sys->p_info->sequence->width
 530                      * p_sys->p_info->sequence->height );
 531             memset( p_pic->p[1].p_pixels, 0x80,
 532                     p_sys->p_info->sequence->width
 533                      * p_sys->p_info->sequence->height / 4 );
 534             memset( p_pic->p[2].p_pixels, 0x80,
 535                     p_sys->p_info->sequence->width
 536                      * p_sys->p_info->sequence->height / 4 );
 537
 538             if( p_sys->b_slice_i )
 539             {
 540                 decoder_SynchroNewPicture( p_sys->p_synchro,
 541                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 542                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 543                 decoder_SynchroDecode( p_sys->p_synchro );
 544                 decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 545             }
 546             break;
 547         }
 548
 549         default:
 550             break;
 551         }
 552     }
 553
 554     /* Never reached */
 555     return NULL;
 556 }
 557
 558 /*****************************************************************************
 559  * CloseDecoder: libmpeg2 decoder destruction
 560  *****************************************************************************/
 561 static void CloseDecoder( vlc_object_t *p_this )
 562 {
 563     decoder_t *p_dec = (decoder_t *)p_this;
 564     decoder_sys_t *p_sys = p_dec->p_sys;
 565
 566     if( p_sys->p_synchro ) decoder_SynchroRelease( p_sys->p_synchro );
 567
 568     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 569
 570     free( p_sys );
 571 }
 572
 573 /*****************************************************************************
 574  * GetNewPicture: Get a new picture from the vout and set the buf struct
 575  *****************************************************************************/
 576 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
 577 {
 578     decoder_sys_t *p_sys = p_dec->p_sys;
 579     picture_t *p_pic;
 580
 581     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
 582     p_dec->fmt_out.video.i_visible_width =
 583         p_sys->p_info->sequence->picture_width;
 584     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
 585     p_dec->fmt_out.video.i_visible_height =
 586         p_sys->p_info->sequence->picture_height;
 587     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
 588     p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
 589     p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;
 590
 591     if( p_sys->p_info->sequence->frame_period > 0 )
 592     {
 593         p_dec->fmt_out.video.i_frame_rate =
 594             (uint32_t)( (uint64_t)1001000000 * 27 /
 595                         p_sys->p_info->sequence->frame_period );
 596         p_dec->fmt_out.video.i_frame_rate_base = 1001;
 597     }
 598
 599     p_dec->fmt_out.i_codec =
 600         ( p_sys->p_info->sequence->chroma_height <
 601           p_sys->p_info->sequence->height ) ?
 602         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
 603
 604     /* Get a new picture */
 605     p_pic = p_dec->pf_vout_buffer_new( p_dec );
 606
 607     if( p_pic == NULL ) return NULL;
 608
 609     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 610         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 611     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 612         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 613     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 614         p_sys->p_info->current_picture->nb_fields : 2;
 615
 616     p_dec->pf_picture_link( p_dec, p_pic );
 617
 618     pp_buf[0] = p_pic->p[0].p_pixels;
 619     pp_buf[1] = p_pic->p[1].p_pixels;
 620     pp_buf[2] = p_pic->p[2].p_pixels;
 621
 622     return p_pic;
 623 }
 624
 625 /*****************************************************************************
 626  * GetAR: Get aspect ratio
 627  *****************************************************************************/
 628 static void GetAR( decoder_t *p_dec )
 629 {
 630     decoder_sys_t *p_sys = p_dec->p_sys;
 631
 632     /* Check whether the input gave a particular aspect ratio */
 633     if( p_dec->fmt_in.video.i_aspect )
 634     {
 635         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 636         if( p_sys->i_aspect <= AR_221_1_PICTURE )
 637         switch( p_sys->i_aspect )
 638         {
 639         case AR_4_3_PICTURE:
 640             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 641             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
 642             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
 643             break;
 644         case AR_16_9_PICTURE:
 645             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 646             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 16;
 647             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 9;
 648             break;
 649         case AR_221_1_PICTURE:
 650             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 651             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 221;
 652             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 100;
 653             break;
 654         case AR_SQUARE_PICTURE:
 655             p_sys->i_aspect = VOUT_ASPECT_FACTOR *
 656                            p_sys->p_info->sequence->picture_width /
 657                            p_sys->p_info->sequence->picture_height;
 658             p_sys->i_sar_num = p_sys->i_sar_den = 1;
 659             break;
 660         }
 661     }
 662     else
 663     {
 664         /* Use the value provided in the MPEG sequence header */
 665         if( p_sys->p_info->sequence->pixel_height > 0 )
 666         {
 667             p_sys->i_aspect =
 668                 ((uint64_t)p_sys->p_info->sequence->picture_width) *
 669                 p_sys->p_info->sequence->pixel_width *
 670                 VOUT_ASPECT_FACTOR /
 671                 p_sys->p_info->sequence->picture_height /
 672                 p_sys->p_info->sequence->pixel_height;
 673             p_sys->i_sar_num = p_sys->p_info->sequence->pixel_width;
 674             p_sys->i_sar_den = p_sys->p_info->sequence->pixel_height;
 675         }
 676         else
 677         {
 678             /* Invalid aspect, assume 4:3.
 679              * This shouldn't happen and if it does it is a bug
 680              * in libmpeg2 (likely triggered by an invalid stream) */
 681             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 682             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
 683             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
 684         }
 685     }
 686
 687     msg_Dbg( p_dec, "%dx%d (display %d,%d), aspect %d, sar %i:%i, %u.%03u fps",
 688              p_sys->p_info->sequence->picture_width,
 689              p_sys->p_info->sequence->picture_height,
 690              p_sys->p_info->sequence->display_width,
 691              p_sys->p_info->sequence->display_height,
 692              p_sys->i_aspect, p_sys->i_sar_num, p_sys->i_sar_den,
 693              (uint32_t)((uint64_t)1001000000 * 27 /
 694                  p_sys->p_info->sequence->frame_period / 1001),
 695              (uint32_t)((uint64_t)1001000000 * 27 /
 696                  p_sys->p_info->sequence->frame_period % 1001) );
 697 }