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/vlc.h>
  33 #include <vlc_vout.h>
  34 #include <vlc_codec.h>
  35
  36 #include <mpeg2dec/mpeg2.h>
  37
  38 #include <vlc_codec_synchro.h>
  39
  40 /* Aspect ratio (ISO/IEC 13818-2 section 6.3.3, table 6-3) */
  41 #define AR_SQUARE_PICTURE       1                           /* square pixels */
  42 #define AR_4_3_PICTURE          2                        /* 4:3 picture (TV) */
  43 #define AR_16_9_PICTURE         3              /* 16:9 picture (wide screen) */
  44 #define AR_221_1_PICTURE        4                  /* 2.21:1 picture (movie) */
  45
  46 /*****************************************************************************
  47  * decoder_sys_t : libmpeg2 decoder descriptor
  48  *****************************************************************************/
  49 struct decoder_sys_t
  50 {
  51     /*
  52      * libmpeg2 properties
  53      */
  54     mpeg2dec_t          *p_mpeg2dec;
  55     const mpeg2_info_t  *p_info;
  56     vlc_bool_t          b_skip;
  57
  58     /*
  59      * Input properties
  60      */
  61     mtime_t          i_previous_pts;
  62     mtime_t          i_current_pts;
  63     mtime_t          i_previous_dts;
  64     mtime_t          i_current_dts;
  65     int              i_current_rate;
  66     picture_t *      p_picture_to_destroy;
  67     vlc_bool_t       b_garbage_pic;
  68     vlc_bool_t       b_after_sequence_header; /* is it the next frame after
  69                                                * the sequence header ?    */
  70     vlc_bool_t       b_slice_i;             /* intra-slice refresh stream */
  71     vlc_bool_t       b_second_field;
  72
  73     vlc_bool_t       b_preroll;
  74
  75     /*
  76      * Output properties
  77      */
  78     decoder_synchro_t *p_synchro;
  79     int            i_aspect;
  80     int            i_sar_num;
  81     int            i_sar_den;
  82     mtime_t        i_last_frame_pts;
  83
  84 };
  85
  86 /*****************************************************************************
  87  * Local prototypes
  88  *****************************************************************************/
  89 static int  OpenDecoder( vlc_object_t * );
  90 static void CloseDecoder( vlc_object_t * );
  91
  92 static picture_t *DecodeBlock( decoder_t *, block_t ** );
  93
  94 static picture_t *GetNewPicture( decoder_t *, uint8_t ** );
  95 static void GetAR( decoder_t *p_dec );
  96
  97 /*****************************************************************************
  98  * Module descriptor
  99  *****************************************************************************/
 100 vlc_module_begin();
 101     set_description( _("MPEG I/II video decoder (using libmpeg2)") );
 102     set_capability( "decoder", 150 );
 103     set_category( CAT_INPUT );
 104     set_subcategory( SUBCAT_INPUT_VCODEC );
 105     set_callbacks( OpenDecoder, CloseDecoder );
 106     add_shortcut( "libmpeg2" );
 107 vlc_module_end();
 108
 109 /*****************************************************************************
 110  * OpenDecoder: probe the decoder and return score
 111  *****************************************************************************/
 112 static int OpenDecoder( vlc_object_t *p_this )
 113 {
 114     decoder_t *p_dec = (decoder_t*)p_this;
 115     decoder_sys_t *p_sys;
 116     uint32_t i_accel = 0;
 117
 118     if( p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','v') &&
 119         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','1') &&
 120         /* Pinnacle hardware-mpeg1 */
 121         p_dec->fmt_in.i_codec != VLC_FOURCC('P','I','M','1') &&
 122         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','2','v') &&
 123         p_dec->fmt_in.i_codec != VLC_FOURCC('m','p','g','2') &&
 124         p_dec->fmt_in.i_codec != VLC_FOURCC('h','d','v','2') )
 125     {
 126         return VLC_EGENERIC;
 127     }
 128
 129     /* Allocate the memory needed to store the decoder's structure */
 130     if( ( p_dec->p_sys = p_sys =
 131           (decoder_sys_t *)malloc(sizeof(decoder_sys_t)) ) == NULL )
 132     {
 133         msg_Err( p_dec, "out of memory" );
 134         return VLC_EGENERIC;
 135     }
 136
 137     /* Initialize the thread properties */
 138     memset( p_sys, 0, sizeof(decoder_sys_t) );
 139     p_sys->p_mpeg2dec = NULL;
 140     p_sys->p_synchro  = NULL;
 141     p_sys->p_info     = NULL;
 142     p_sys->i_current_pts  = 0;
 143     p_sys->i_previous_pts = 0;
 144     p_sys->i_current_dts  = 0;
 145     p_sys->i_previous_dts = 0;
 146     p_sys->p_picture_to_destroy = NULL;
 147     p_sys->b_garbage_pic = 0;
 148     p_sys->b_slice_i  = 0;
 149     p_sys->b_second_field = 0;
 150     p_sys->b_skip     = 0;
 151     p_sys->b_preroll = VLC_FALSE;
 152
 153 #if defined( __i386__ ) || defined( __x86_64__ )
 154     if( vlc_CPU() & CPU_CAPABILITY_MMX )
 155     {
 156         i_accel |= MPEG2_ACCEL_X86_MMX;
 157     }
 158
 159     if( vlc_CPU() & CPU_CAPABILITY_3DNOW )
 160     {
 161         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 162     }
 163
 164     if( vlc_CPU() & CPU_CAPABILITY_MMXEXT )
 165     {
 166         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 167     }
 168
 169 #elif defined( __powerpc__ ) || defined( __ppc__ ) || defined( __ppc64__ )
 170     if( vlc_CPU() & CPU_CAPABILITY_ALTIVEC )
 171     {
 172         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
 173     }
 174
 175 #else
 176     /* If we do not know this CPU, trust libmpeg2's feature detection */
 177     i_accel = MPEG2_ACCEL_DETECT;
 178
 179 #endif
 180
 181     /* Set CPU acceleration features */
 182     mpeg2_accel( i_accel );
 183
 184     /* Initialize decoder */
 185     p_sys->p_mpeg2dec = mpeg2_init();
 186     if( p_sys->p_mpeg2dec == NULL)
 187     {
 188         msg_Err( p_dec, "mpeg2_init() failed" );
 189         free( p_sys );
 190         return VLC_EGENERIC;
 191     }
 192
 193     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
 194
 195     p_dec->pf_decode_video = DecodeBlock;
 196
 197     return VLC_SUCCESS;
 198 }
 199
 200 /*****************************************************************************
 201  * RunDecoder: the libmpeg2 decoder
 202  *****************************************************************************/
 203 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 204 {
 205     decoder_sys_t   *p_sys = p_dec->p_sys;
 206     mpeg2_state_t   state;
 207     picture_t       *p_pic;
 208
 209     block_t *p_block;
 210
 211     if( !pp_block || !*pp_block ) return NULL;
 212
 213     p_block = *pp_block;
 214
 215     while( 1 )
 216     {
 217         state = mpeg2_parse( p_sys->p_mpeg2dec );
 218
 219         switch( state )
 220         {
 221         case STATE_BUFFER:
 222             if( !p_block->i_buffer )
 223             {
 224                 block_Release( p_block );
 225                 return NULL;
 226             }
 227
 228             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
 229                                       | BLOCK_FLAG_CORRUPTED)) &&
 230                 p_sys->p_synchro &&
 231                 p_sys->p_info->sequence &&
 232                 p_sys->p_info->sequence->width != (unsigned)-1 )
 233             {
 234                 decoder_SynchroReset( p_sys->p_synchro );
 235                 if( p_sys->p_info->current_fbuf != NULL
 236                     && p_sys->p_info->current_fbuf->id != NULL )
 237                 {
 238                     p_sys->b_garbage_pic = 1;
 239                     p_pic = p_sys->p_info->current_fbuf->id;
 240                 }
 241                 else
 242                 {
 243                     uint8_t *buf[3];
 244                     buf[0] = buf[1] = buf[2] = NULL;
 245                     if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 246                         break;
 247                     mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 248                     mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 249                 }
 250                 p_sys->p_picture_to_destroy = p_pic;
 251
 252                 if ( p_sys->b_slice_i )
 253                 {
 254                     decoder_SynchroNewPicture( p_sys->p_synchro,
 255                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 256                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 257                     decoder_SynchroDecode( p_sys->p_synchro );
 258                     decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 259                 }
 260             }
 261
 262             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
 263             {
 264                 p_sys->b_preroll = VLC_TRUE;
 265             }
 266             else if( p_sys->b_preroll )
 267             {
 268                 p_sys->b_preroll = VLC_FALSE;
 269                 /* Reset synchro */
 270                 decoder_SynchroReset( p_sys->p_synchro );
 271             }
 272
 273 #ifdef PIC_FLAG_PTS
 274             if( p_block->i_pts )
 275             {
 276                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 277
 278 #else /* New interface */
 279             if( p_block->i_pts || p_block->i_dts )
 280             {
 281                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
 282                                    (uint32_t)p_block->i_pts,
 283                                    (uint32_t)p_block->i_dts );
 284 #endif
 285                 p_sys->i_previous_pts = p_sys->i_current_pts;
 286                 p_sys->i_current_pts = p_block->i_pts;
 287                 p_sys->i_previous_dts = p_sys->i_current_dts;
 288                 p_sys->i_current_dts = p_block->i_dts;
 289             }
 290
 291             p_sys->i_current_rate = p_block->i_rate;
 292
 293             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 294                           p_block->p_buffer + p_block->i_buffer );
 295
 296             p_block->i_buffer = 0;
 297             break;
 298
 299 #ifdef STATE_SEQUENCE_MODIFIED
 300 /* FIXME - the above ifdef is always FALSE, even with libmpeg2-0.5.0
 301  * Need to improve the implementation to avoid invalid/unref pictures */
 302
 303         case STATE_SEQUENCE_MODIFIED:
 304             GetAR( p_dec );
 305             break;
 306 #endif
 307
 308         case STATE_SEQUENCE:
 309         {
 310             /* Initialize video output */
 311             uint8_t *buf[3];
 312             buf[0] = buf[1] = buf[2] = NULL;
 313
 314             GetAR( p_dec );
 315
 316             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 317
 318             /* Set the first 2 reference frames */
 319             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 320
 321             if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 322             {
 323                 block_Release( p_block );
 324                 return NULL;
 325             }
 326
 327             mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 328         mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 329
 330             /* This picture will never go through display_picture. */
 331             p_pic->date = 0;
 332
 333             /* For some reason, libmpeg2 will put this pic twice in
 334              * discard_picture. This can be considered a bug in libmpeg2. */
 335             p_dec->pf_picture_link( p_dec, p_pic );
 336
 337             if( p_sys->p_synchro )
 338             {
 339                 decoder_SynchroRelease( p_sys->p_synchro );
 340             }
 341             p_sys->p_synchro = decoder_SynchroInit( p_dec,
 342                 (uint32_t)((uint64_t)1001000000 * 27 /
 343                 p_sys->p_info->sequence->frame_period) );
 344             p_sys->b_after_sequence_header = 1;
 345         }
 346         break;
 347
 348         case STATE_PICTURE_2ND:
 349             p_sys->b_second_field = 1;
 350             break;
 351
 352         case STATE_PICTURE:
 353         {
 354             uint8_t *buf[3];
 355             mtime_t i_pts, i_dts;
 356             buf[0] = buf[1] = buf[2] = NULL;
 357
 358             if ( p_sys->b_after_sequence_header &&
 359                  ((p_sys->p_info->current_picture->flags &
 360                        PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P) )
 361             {
 362                 /* Intra-slice refresh. Simulate a blank I picture. */
 363                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 364                 decoder_SynchroNewPicture( p_sys->p_synchro,
 365                     I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 366                     p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 367                 decoder_SynchroDecode( p_sys->p_synchro );
 368                 decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 369                 p_sys->b_slice_i = 1;
 370             }
 371             p_sys->b_after_sequence_header = 0;
 372
 373 #ifdef PIC_FLAG_PTS
 374             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_PTS ?
 375                 ( ( p_sys->p_info->current_picture->pts ==
 376                     (uint32_t)p_sys->i_current_pts ) ?
 377                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 378             i_dts = 0;
 379
 380             /* Hack to handle demuxers which only have DTS timestamps */
 381             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 382             {
 383                 if( p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 384                     (p_sys->p_info->current_picture->flags &
 385                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 386                 {
 387                     i_pts = p_block->i_dts;
 388                 }
 389             }
 390             p_block->i_pts = p_block->i_dts = 0;
 391             /* End hack */
 392
 393 #else /* New interface */
 394
 395             i_pts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 396                 ( ( p_sys->p_info->current_picture->tag ==
 397                     (uint32_t)p_sys->i_current_pts ) ?
 398                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 399             i_dts = p_sys->p_info->current_picture->flags & PIC_FLAG_TAGS ?
 400                 ( ( p_sys->p_info->current_picture->tag2 ==
 401                     (uint32_t)p_sys->i_current_dts ) ?
 402                   p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 403 #endif
 404
 405             /* If nb_fields == 1, it is a field picture, and it will be
 406              * followed by another field picture for which we won't call
 407              * decoder_SynchroNewPicture() because this would have other
 408              * problems, so we take it into account here.
 409              * This kind of sucks, but I didn't think better. --Meuuh
 410              */
 411             decoder_SynchroNewPicture( p_sys->p_synchro,
 412                 p_sys->p_info->current_picture->flags & PIC_MASK_CODING_TYPE,
 413                 p_sys->p_info->current_picture->nb_fields == 1 ? 2 :
 414                 p_sys->p_info->current_picture->nb_fields, i_pts, i_dts,
 415                 p_sys->i_current_rate,
 416                 p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 417
 418             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
 419                 !(p_sys->b_slice_i
 420                    && ((p_sys->p_info->current_picture->flags
 421                          & PIC_MASK_CODING_TYPE) == P_CODING_TYPE))
 422                    && !decoder_SynchroChoose( p_sys->p_synchro,
 423                               p_sys->p_info->current_picture->flags
 424                                 & PIC_MASK_CODING_TYPE,
 425                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
 426                               p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
 427             {
 428                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 429                 p_sys->b_skip = 1;
 430                 decoder_SynchroTrash( p_sys->p_synchro );
 431                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, NULL );
 432             }
 433             else
 434             {
 435                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 436                 p_sys->b_skip = 0;
 437                 decoder_SynchroDecode( p_sys->p_synchro );
 438
 439                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 440                 {
 441                     block_Release( p_block );
 442                     return NULL;
 443                 }
 444
 445                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 446         mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 447             }
 448         }
 449         break;
 450
 451         case STATE_END:
 452         case STATE_SLICE:
 453             p_pic = NULL;
 454             if( p_sys->p_info->display_fbuf
 455                 && p_sys->p_info->display_fbuf->id )
 456             {
 457                 p_pic = (picture_t *)p_sys->p_info->display_fbuf->id;
 458
 459                 decoder_SynchroEnd( p_sys->p_synchro,
 460                             p_sys->p_info->display_picture->flags
 461                              & PIC_MASK_CODING_TYPE,
 462                             p_sys->b_garbage_pic );
 463                 p_sys->b_garbage_pic = 0;
 464
 465                 if ( p_sys->p_picture_to_destroy != p_pic )
 466                 {
 467                     p_pic->date = decoder_SynchroDate( p_sys->p_synchro );
 468                 }
 469                 else
 470                 {
 471                     p_sys->p_picture_to_destroy = NULL;
 472                     p_pic->date = 0;
 473                 }
 474             }
 475
 476             if( p_sys->p_info->discard_fbuf &&
 477                 p_sys->p_info->discard_fbuf->id )
 478             {
 479                 p_dec->pf_picture_unlink( p_dec,
 480                                           p_sys->p_info->discard_fbuf->id );
 481             }
 482
 483             /* For still frames */
 484             if( state == STATE_END && p_pic ) p_pic->b_force = VLC_TRUE;
 485
 486             if( p_pic )
 487             {
 488                 /* Avoid frames with identical timestamps.
 489                  * Especially needed for still frames in DVD menus. */
 490                 if( p_sys->i_last_frame_pts == p_pic->date ) p_pic->date++;
 491                 p_sys->i_last_frame_pts = p_pic->date;
 492
 493                 return p_pic;
 494             }
 495
 496             break;
 497
 498         case STATE_INVALID:
 499         {
 500             uint8_t *buf[3];
 501             buf[0] = buf[1] = buf[2] = NULL;
 502
 503             msg_Warn( p_dec, "invalid picture encountered" );
 504             if ( ( p_sys->p_info->current_picture == NULL ) ||
 505                ( ( p_sys->p_info->current_picture->flags &
 506                    PIC_MASK_CODING_TYPE) != B_CODING_TYPE ) )
 507             {
 508                 if( p_sys->p_synchro ) decoder_SynchroReset( p_sys->p_synchro );
 509             }
 510             mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 511             p_sys->b_skip = 1;
 512
 513             if( p_sys->p_info->current_fbuf &&
 514                 p_sys->p_info->current_fbuf->id )
 515             {
 516                 p_sys->b_garbage_pic = 1;
 517                 p_pic = p_sys->p_info->current_fbuf->id;
 518             }
 519             else if( !p_sys->p_info->sequence )
 520             {
 521                 break;
 522             }
 523             else
 524             {
 525                 if( (p_pic = GetNewPicture( p_dec, buf )) == NULL )
 526                     break;
 527                 mpeg2_set_buf( p_sys->p_mpeg2dec, buf, p_pic );
 528         mpeg2_stride( p_sys->p_mpeg2dec, p_pic->p[Y_PLANE].i_pitch );
 529             }
 530             p_sys->p_picture_to_destroy = p_pic;
 531
 532             memset( p_pic->p[0].p_pixels, 0,
 533                     p_sys->p_info->sequence->width
 534                      * p_sys->p_info->sequence->height );
 535             memset( p_pic->p[1].p_pixels, 0x80,
 536                     p_sys->p_info->sequence->width
 537                      * p_sys->p_info->sequence->height / 4 );
 538             memset( p_pic->p[2].p_pixels, 0x80,
 539                     p_sys->p_info->sequence->width
 540                      * p_sys->p_info->sequence->height / 4 );
 541
 542             if( p_sys->b_slice_i )
 543             {
 544                 decoder_SynchroNewPicture( p_sys->p_synchro,
 545                         I_CODING_TYPE, 2, 0, 0, p_sys->i_current_rate,
 546                         p_sys->p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 547                 decoder_SynchroDecode( p_sys->p_synchro );
 548                 decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 549             }
 550             break;
 551         }
 552
 553         default:
 554             break;
 555         }
 556     }
 557
 558     /* Never reached */
 559     return NULL;
 560 }
 561
 562 /*****************************************************************************
 563  * CloseDecoder: libmpeg2 decoder destruction
 564  *****************************************************************************/
 565 static void CloseDecoder( vlc_object_t *p_this )
 566 {
 567     decoder_t *p_dec = (decoder_t *)p_this;
 568     decoder_sys_t *p_sys = p_dec->p_sys;
 569
 570     if( p_sys->p_synchro ) decoder_SynchroRelease( p_sys->p_synchro );
 571
 572     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 573
 574     free( p_sys );
 575 }
 576
 577 /*****************************************************************************
 578  * GetNewPicture: Get a new picture from the vout and set the buf struct
 579  *****************************************************************************/
 580 static picture_t *GetNewPicture( decoder_t *p_dec, uint8_t **pp_buf )
 581 {
 582     decoder_sys_t *p_sys = p_dec->p_sys;
 583     picture_t *p_pic;
 584
 585     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
 586     p_dec->fmt_out.video.i_visible_width =
 587         p_sys->p_info->sequence->picture_width;
 588     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
 589     p_dec->fmt_out.video.i_visible_height =
 590         p_sys->p_info->sequence->picture_height;
 591     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
 592     p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
 593     p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;
 594
 595     if( p_sys->p_info->sequence->frame_period > 0 )
 596     {
 597         p_dec->fmt_out.video.i_frame_rate =
 598             (uint32_t)( (uint64_t)1001000000 * 27 /
 599                         p_sys->p_info->sequence->frame_period );
 600         p_dec->fmt_out.video.i_frame_rate_base = 1001;
 601     }
 602
 603     p_dec->fmt_out.i_codec =
 604         ( p_sys->p_info->sequence->chroma_height <
 605           p_sys->p_info->sequence->height ) ?
 606         VLC_FOURCC('I','4','2','0') : VLC_FOURCC('I','4','2','2');
 607
 608     /* Get a new picture */
 609     p_pic = p_dec->pf_vout_buffer_new( p_dec );
 610
 611     if( p_pic == NULL ) return NULL;
 612
 613     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 614         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 615     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 616         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 617     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 618         p_sys->p_info->current_picture->nb_fields : 2;
 619
 620     p_dec->pf_picture_link( p_dec, p_pic );
 621
 622     pp_buf[0] = p_pic->p[0].p_pixels;
 623     pp_buf[1] = p_pic->p[1].p_pixels;
 624     pp_buf[2] = p_pic->p[2].p_pixels;
 625
 626     return p_pic;
 627 }
 628
 629 /*****************************************************************************
 630  * GetAR: Get aspect ratio
 631  *****************************************************************************/
 632 static void GetAR( decoder_t *p_dec )
 633 {
 634     decoder_sys_t *p_sys = p_dec->p_sys;
 635
 636     /* Check whether the input gave a particular aspect ratio */
 637     if( p_dec->fmt_in.video.i_aspect )
 638     {
 639         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 640         if( p_sys->i_aspect <= AR_221_1_PICTURE )
 641         switch( p_sys->i_aspect )
 642         {
 643         case AR_4_3_PICTURE:
 644             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 645             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
 646             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
 647             break;
 648         case AR_16_9_PICTURE:
 649             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 16 / 9;
 650             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 16;
 651             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 9;
 652             break;
 653         case AR_221_1_PICTURE:
 654             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 221 / 100;
 655             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 221;
 656             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 100;
 657             break;
 658         case AR_SQUARE_PICTURE:
 659             p_sys->i_aspect = VOUT_ASPECT_FACTOR *
 660                            p_sys->p_info->sequence->picture_width /
 661                            p_sys->p_info->sequence->picture_height;
 662             p_sys->i_sar_num = p_sys->i_sar_den = 1;
 663             break;
 664         }
 665     }
 666     else
 667     {
 668         /* Use the value provided in the MPEG sequence header */
 669         if( p_sys->p_info->sequence->pixel_height > 0 )
 670         {
 671             p_sys->i_aspect =
 672                 ((uint64_t)p_sys->p_info->sequence->picture_width) *
 673                 p_sys->p_info->sequence->pixel_width *
 674                 VOUT_ASPECT_FACTOR /
 675                 p_sys->p_info->sequence->picture_height /
 676                 p_sys->p_info->sequence->pixel_height;
 677             p_sys->i_sar_num = p_sys->p_info->sequence->pixel_width;
 678             p_sys->i_sar_den = p_sys->p_info->sequence->pixel_height;
 679         }
 680         else
 681         {
 682             /* Invalid aspect, assume 4:3.
 683              * This shouldn't happen and if it does it is a bug
 684              * in libmpeg2 (likely triggered by an invalid stream) */
 685             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 686             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
 687             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
 688         }
 689     }
 690
 691     msg_Dbg( p_dec, "%dx%d (display %d,%d), aspect %d, sar %i:%i, %u.%03u fps",
 692              p_sys->p_info->sequence->picture_width,
 693              p_sys->p_info->sequence->picture_height,
 694              p_sys->p_info->sequence->display_width,
 695              p_sys->p_info->sequence->display_height,
 696              p_sys->i_aspect, p_sys->i_sar_num, p_sys->i_sar_den,
 697              (uint32_t)((uint64_t)1001000000 * 27 /
 698                  p_sys->p_info->sequence->frame_period / 1001),
 699              (uint32_t)((uint64_t)1001000000 * 27 /
 700                  p_sys->p_info->sequence->frame_period % 1001) );
 701 }