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 #include <assert.h>
  32
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_codec.h>
  36 #include <vlc_block_helper.h>
  37 #include <vlc_cpu.h>
  38 #include "../codec/cc.h"
  39
  40 #include <mpeg2.h>
  41
  42 #include <vlc_codec_synchro.h>
  43
  44 /*****************************************************************************
  45  * decoder_sys_t : libmpeg2 decoder descriptor
  46  *****************************************************************************/
  47 #define DPB_COUNT (3+1)
  48 typedef struct
  49 {
  50     picture_t *p_picture;
  51     bool      b_linked;
  52     bool      b_displayed;
  53 } picture_dpb_t;
  54
  55 struct decoder_sys_t
  56 {
  57     /*
  58      * libmpeg2 properties
  59      */
  60     mpeg2dec_t          *p_mpeg2dec;
  61     const mpeg2_info_t  *p_info;
  62     bool                b_skip;
  63
  64     /*
  65      * Input properties
  66      */
  67     mtime_t          i_previous_pts;
  68     mtime_t          i_current_pts;
  69     mtime_t          i_previous_dts;
  70     mtime_t          i_current_dts;
  71     bool             b_garbage_pic;
  72     bool             b_after_sequence_header; /* is it the next frame after
  73                                                * the sequence header ?    */
  74     bool             b_slice_i;             /* intra-slice refresh stream */
  75     bool             b_second_field;
  76
  77     bool             b_preroll;
  78
  79     /* */
  80     picture_dpb_t        p_dpb[DPB_COUNT];
  81
  82     /*
  83      * Output properties
  84      */
  85     decoder_synchro_t *p_synchro;
  86     int             i_aspect;
  87     int             i_sar_num;
  88     int             i_sar_den;
  89     mtime_t         i_last_frame_pts;
  90
  91     /* Closed captioning support */
  92     uint32_t        i_cc_flags;
  93     mtime_t         i_cc_pts;
  94     mtime_t         i_cc_dts;
  95     cc_data_t       cc;
  96     uint8_t        *p_gop_user_data;
  97     uint32_t        i_gop_user_data;
  98 };
  99
 100 /*****************************************************************************
 101  * Local prototypes
 102  *****************************************************************************/
 103 static int  OpenDecoder( vlc_object_t * );
 104 static void CloseDecoder( vlc_object_t * );
 105
 106 static picture_t *DecodeBlock( decoder_t *, block_t ** );
 107 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
 108 static block_t   *GetCc( decoder_t *p_dec, bool pb_present[4] );
 109 #endif
 110
 111 static picture_t *GetNewPicture( decoder_t * );
 112 static void PutPicture( decoder_t *, picture_t * );
 113
 114 static void GetAR( decoder_t *p_dec );
 115
 116 static void Reset( decoder_t *p_dec );
 117
 118 /* */
 119 static void DpbInit( decoder_t * );
 120 static void DpbClean( decoder_t * );
 121 static picture_t *DpbNewPicture( decoder_t * );
 122 static void DpbUnlinkPicture( decoder_t *, picture_t * );
 123 static int DpbDisplayPicture( decoder_t *, picture_t * );
 124
 125 /*****************************************************************************
 126  * Module descriptor
 127  *****************************************************************************/
 128 vlc_module_begin ()
 129     set_description( N_("MPEG I/II video decoder (using libmpeg2)") )
 130     set_capability( "decoder", 150 )
 131     set_category( CAT_INPUT )
 132     set_subcategory( SUBCAT_INPUT_VCODEC )
 133     set_callbacks( OpenDecoder, CloseDecoder )
 134     add_shortcut( "libmpeg2" )
 135 vlc_module_end ()
 136
 137 /*****************************************************************************
 138  * OpenDecoder: probe the decoder and return score
 139  *****************************************************************************/
 140 static int OpenDecoder( vlc_object_t *p_this )
 141 {
 142     decoder_t *p_dec = (decoder_t*)p_this;
 143     decoder_sys_t *p_sys;
 144     uint32_t i_accel = 0;
 145
 146     if( p_dec->fmt_in.i_codec != VLC_CODEC_MPGV )
 147         return VLC_EGENERIC;
 148
 149     /* Select onl recognized original format (standard mpeg video) */
 150     switch( p_dec->fmt_in.i_original_fourcc )
 151     {
 152     case VLC_FOURCC('m','p','g','1'):
 153     case VLC_FOURCC('m','p','g','2'):
 154     case VLC_FOURCC('m','p','g','v'):
 155     case VLC_FOURCC('P','I','M','1'):
 156     case VLC_FOURCC('h','d','v','2'):
 157         break;
 158     default:
 159         if( p_dec->fmt_in.i_original_fourcc )
 160             return VLC_EGENERIC;
 161         break;
 162     }
 163
 164     /* Allocate the memory needed to store the decoder's structure */
 165     if( ( p_dec->p_sys = p_sys = calloc( 1, sizeof(*p_sys)) ) == NULL )
 166         return VLC_ENOMEM;
 167
 168     /* Initialize the thread properties */
 169     p_sys->p_mpeg2dec = NULL;
 170     p_sys->p_synchro  = NULL;
 171     p_sys->p_info     = NULL;
 172     p_sys->i_current_pts  = 0;
 173     p_sys->i_previous_pts = 0;
 174     p_sys->i_current_dts  = 0;
 175     p_sys->i_previous_dts = 0;
 176     p_sys->i_aspect = 0;
 177     p_sys->b_garbage_pic = false;
 178     p_sys->b_slice_i  = false;
 179     p_sys->b_second_field = false;
 180     p_sys->b_skip     = false;
 181     p_sys->b_preroll = false;
 182     DpbInit( p_dec );
 183
 184     p_sys->i_cc_pts = 0;
 185     p_sys->i_cc_dts = 0;
 186     p_sys->i_cc_flags = 0;
 187 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
 188     p_dec->pf_get_cc = GetCc;
 189     cc_Init( &p_sys->cc );
 190 #endif
 191     p_sys->p_gop_user_data = NULL;
 192     p_sys->i_gop_user_data = 0;
 193
 194 #if defined( __i386__ ) || defined( __x86_64__ )
 195     if( vlc_CPU() & CPU_CAPABILITY_MMX )
 196     {
 197         i_accel |= MPEG2_ACCEL_X86_MMX;
 198     }
 199
 200     if( vlc_CPU() & CPU_CAPABILITY_3DNOW )
 201     {
 202         i_accel |= MPEG2_ACCEL_X86_3DNOW;
 203     }
 204
 205     if( vlc_CPU() & CPU_CAPABILITY_MMXEXT )
 206     {
 207         i_accel |= MPEG2_ACCEL_X86_MMXEXT;
 208     }
 209
 210 #elif defined( __powerpc__ ) || defined( __ppc__ ) || defined( __ppc64__ )
 211     if( vlc_CPU() & CPU_CAPABILITY_ALTIVEC )
 212     {
 213         i_accel |= MPEG2_ACCEL_PPC_ALTIVEC;
 214     }
 215
 216 #elif defined(__arm__)
 217     i_accel |= MPEG2_ACCEL_ARM;
 218
 219 # ifdef MPEG2_ACCEL_ARM_NEON
 220     if( vlc_CPU() & CPU_CAPABILITY_NEON )
 221         i_accel |= MPEG2_ACCEL_ARM_NEON;
 222 # endif
 223
 224 #else
 225     /* If we do not know this CPU, trust libmpeg2's feature detection */
 226     i_accel = MPEG2_ACCEL_DETECT;
 227
 228 #endif
 229
 230     /* Set CPU acceleration features */
 231     mpeg2_accel( i_accel );
 232
 233     /* Initialize decoder */
 234     p_sys->p_mpeg2dec = mpeg2_init();
 235     if( p_sys->p_mpeg2dec == NULL)
 236     {
 237         msg_Err( p_dec, "mpeg2_init() failed" );
 238         free( p_sys );
 239         return VLC_EGENERIC;
 240     }
 241
 242     p_sys->p_info = mpeg2_info( p_sys->p_mpeg2dec );
 243
 244     p_dec->pf_decode_video = DecodeBlock;
 245     p_dec->fmt_out.i_cat = VIDEO_ES;
 246     p_dec->fmt_out.i_codec = 0;
 247
 248     return VLC_SUCCESS;
 249 }
 250
 251 /*****************************************************************************
 252  * RunDecoder: the libmpeg2 decoder
 253  *****************************************************************************/
 254 static picture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 255 {
 256     decoder_sys_t   *p_sys = p_dec->p_sys;
 257     mpeg2_state_t   state;
 258     picture_t       *p_pic;
 259
 260     block_t *p_block;
 261
 262     if( !pp_block || !*pp_block )
 263         return NULL;
 264
 265     p_block = *pp_block;
 266     if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY | BLOCK_FLAG_CORRUPTED) )
 267         Reset( p_dec );
 268
 269     while( 1 )
 270     {
 271         state = mpeg2_parse( p_sys->p_mpeg2dec );
 272
 273         switch( state )
 274         {
 275         case STATE_SEQUENCE:
 276         {
 277             /* */
 278             DpbClean( p_dec );
 279
 280             /* */
 281             mpeg2_custom_fbuf( p_sys->p_mpeg2dec, 1 );
 282
 283             /* Set the first 2 reference frames */
 284             p_sys->i_aspect = 0;
 285             GetAR( p_dec );
 286             for( int i = 0; i < 2; i++ )
 287             {
 288                 picture_t *p_picture = DpbNewPicture( p_dec );
 289                 if( !p_picture )
 290                 {
 291                     Reset( p_dec );
 292                     block_Release( p_block );
 293                     return NULL;
 294                 }
 295                 PutPicture( p_dec, p_picture );
 296             }
 297
 298             if( p_sys->p_synchro )
 299                 decoder_SynchroRelease( p_sys->p_synchro );
 300
 301             if( p_sys->p_info->sequence->frame_period <= 0 )
 302                 p_sys->p_synchro = NULL;
 303             else
 304                 p_sys->p_synchro =
 305                 decoder_SynchroInit( p_dec, (uint32_t)(UINT64_C(1001000000) *
 306                                 27 / p_sys->p_info->sequence->frame_period) );
 307             p_sys->b_after_sequence_header = true;
 308             break;
 309         }
 310
 311         case STATE_GOP:
 312             /* There can be userdata in a GOP. It needs to be remembered for the next picture. */
 313             if( p_sys->p_info->user_data_len > 2 )
 314             {
 315                 free( p_sys->p_gop_user_data );
 316                 p_sys->p_gop_user_data = calloc( p_sys->p_info->user_data_len, sizeof(uint8_t) );
 317                 if( p_sys->p_gop_user_data )
 318                 {
 319                     p_sys->i_gop_user_data = p_sys->p_info->user_data_len;
 320                     memcpy( p_sys->p_gop_user_data, p_sys->p_info->user_data, p_sys->p_info->user_data_len );
 321                 }
 322             }
 323             break;
 324
 325         case STATE_PICTURE:
 326         {
 327             const mpeg2_info_t *p_info = p_sys->p_info;
 328             const mpeg2_picture_t *p_current = p_info->current_picture;
 329
 330             mtime_t i_pts, i_dts;
 331
 332             if( p_sys->b_after_sequence_header &&
 333                 (p_current->flags &
 334                     PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P )
 335             {
 336                 /* Intra-slice refresh. Simulate a blank I picture. */
 337                 msg_Dbg( p_dec, "intra-slice refresh stream" );
 338                 decoder_SynchroNewPicture( p_sys->p_synchro,
 339                                            I_CODING_TYPE, 2, 0, 0,
 340                                            p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 341                 decoder_SynchroDecode( p_sys->p_synchro );
 342                 decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 343                 p_sys->b_slice_i = true;
 344             }
 345             p_sys->b_after_sequence_header = false;
 346
 347 #ifdef PIC_FLAG_PTS
 348             i_pts = p_current->flags & PIC_FLAG_PTS ?
 349                 ( ( p_current->pts ==
 350                     (uint32_t)p_sys->i_current_pts ) ?
 351                   p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 352             i_dts = 0;
 353
 354             /* Hack to handle demuxers which only have DTS timestamps */
 355             if( !i_pts && !p_block->i_pts && p_block->i_dts > 0 )
 356             {
 357                 if( p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ||
 358                     (p_current->flags &
 359                       PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 360                 {
 361                     i_pts = p_block->i_dts;
 362                 }
 363             }
 364             p_block->i_pts = p_block->i_dts = 0;
 365             /* End hack */
 366
 367 #else /* New interface */
 368
 369             i_pts = p_current->flags & PIC_FLAG_TAGS ?
 370                 ( ( p_current->tag == (uint32_t)p_sys->i_current_pts ) ?
 371                             p_sys->i_current_pts : p_sys->i_previous_pts ) : 0;
 372             i_dts = p_current->flags & PIC_FLAG_TAGS ?
 373                 ( ( p_current->tag2 == (uint32_t)p_sys->i_current_dts ) ?
 374                             p_sys->i_current_dts : p_sys->i_previous_dts ) : 0;
 375 #endif
 376
 377             /* If nb_fields == 1, it is a field picture, and it will be
 378              * followed by another field picture for which we won't call
 379              * decoder_SynchroNewPicture() because this would have other
 380              * problems, so we take it into account here.
 381              * This kind of sucks, but I didn't think better. --Meuuh
 382              */
 383             decoder_SynchroNewPicture( p_sys->p_synchro,
 384                                        p_current->flags & PIC_MASK_CODING_TYPE,
 385                                        p_current->nb_fields == 1 ? 2 :
 386                                        p_current->nb_fields, i_pts, i_dts,
 387                                        p_info->sequence->flags & SEQ_FLAG_LOW_DELAY );
 388
 389
 390             bool b_skip = false;
 391             if( !p_dec->b_pace_control && !p_sys->b_preroll &&
 392                 !(p_sys->b_slice_i
 393                    && ((p_current->flags
 394                          & PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P))
 395                    && !decoder_SynchroChoose( p_sys->p_synchro,
 396                               p_current->flags
 397                                 & PIC_MASK_CODING_TYPE,
 398                               /*p_sys->p_vout->render_time*/ 0 /*FIXME*/,
 399                               p_info->sequence->flags & SEQ_FLAG_LOW_DELAY ) )
 400             {
 401                 b_skip = true;
 402             }
 403
 404             p_pic = NULL;
 405             if( !b_skip )
 406             {
 407                 p_pic = DpbNewPicture( p_dec );
 408                 if( !p_pic )
 409                 {
 410                     Reset( p_dec );
 411
 412                     p_pic = DpbNewPicture( p_dec );
 413                     if( !p_pic )
 414                     {
 415                         mpeg2_reset( p_sys->p_mpeg2dec, 1 );
 416                         block_Release( p_block );
 417                         return NULL;
 418                     }
 419                 }
 420             }
 421
 422             if( b_skip || !p_pic )
 423             {
 424                 mpeg2_skip( p_sys->p_mpeg2dec, 1 );
 425                 p_sys->b_skip = true;
 426                 decoder_SynchroTrash( p_sys->p_synchro );
 427
 428                 PutPicture( p_dec, NULL );
 429
 430                 if( !b_skip )
 431                 {
 432                     block_Release( p_block );
 433                     return NULL;
 434                 }
 435             }
 436             else
 437             {
 438                 mpeg2_skip( p_sys->p_mpeg2dec, 0 );
 439                 p_sys->b_skip = false;
 440                 decoder_SynchroDecode( p_sys->p_synchro );
 441
 442                 PutPicture( p_dec, p_pic );
 443             }
 444             if( p_info->user_data_len > 2 || p_sys->i_gop_user_data > 2 )
 445             {
 446                 p_sys->i_cc_pts = i_pts;
 447                 p_sys->i_cc_dts = i_dts;
 448                 if( (p_current->flags
 449                              & PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_P )
 450                     p_sys->i_cc_flags = BLOCK_FLAG_TYPE_P;
 451                 else if( (p_current->flags
 452                              & PIC_MASK_CODING_TYPE) == PIC_FLAG_CODING_TYPE_B )
 453                     p_sys->i_cc_flags = BLOCK_FLAG_TYPE_B;
 454                 else p_sys->i_cc_flags = BLOCK_FLAG_TYPE_I;
 455
 456                 if( p_sys->i_gop_user_data > 2 )
 457                 {
 458                     /* We now have picture info for any cached user_data out of the gop */
 459                     cc_Extract( &p_sys->cc, &p_sys->p_gop_user_data[0], p_sys->i_gop_user_data );
 460                     p_sys->i_gop_user_data = 0;
 461                 }
 462
 463                 /* Extract the CC from the user_data of the picture */
 464                 if( p_info->user_data_len > 2 )
 465                     cc_Extract( &p_sys->cc, &p_info->user_data[0], p_info->user_data_len );
 466             }
 467         }
 468         break;
 469
 470
 471         case STATE_BUFFER:
 472             if( !p_block->i_buffer )
 473             {
 474                 block_Release( p_block );
 475                 return NULL;
 476             }
 477
 478             if( (p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY
 479                                       | BLOCK_FLAG_CORRUPTED)) &&
 480                 p_sys->p_synchro &&
 481                 p_sys->p_info->sequence &&
 482                 p_sys->p_info->sequence->width != (unsigned)-1 )
 483             {
 484                 decoder_SynchroReset( p_sys->p_synchro );
 485                 if( p_sys->p_info->current_fbuf != NULL &&
 486                     p_sys->p_info->current_fbuf->id != NULL )
 487                 {
 488                     p_sys->b_garbage_pic = true;
 489                 }
 490                 if( p_sys->b_slice_i )
 491                 {
 492                     decoder_SynchroNewPicture( p_sys->p_synchro,
 493                                                I_CODING_TYPE, 2, 0, 0,
 494                                                p_sys->p_info->sequence->flags &
 495                                                             SEQ_FLAG_LOW_DELAY );
 496                     decoder_SynchroDecode( p_sys->p_synchro );
 497                     decoder_SynchroEnd( p_sys->p_synchro, I_CODING_TYPE, 0 );
 498                 }
 499             }
 500
 501             if( p_block->i_flags & BLOCK_FLAG_PREROLL )
 502             {
 503                 p_sys->b_preroll = true;
 504             }
 505             else if( p_sys->b_preroll )
 506             {
 507                 p_sys->b_preroll = false;
 508                 if( p_sys->p_synchro )
 509                     decoder_SynchroReset( p_sys->p_synchro );
 510             }
 511
 512 #ifdef PIC_FLAG_PTS
 513             if( p_block->i_pts )
 514             {
 515                 mpeg2_pts( p_sys->p_mpeg2dec, (uint32_t)p_block->i_pts );
 516
 517 #else /* New interface */
 518             if( p_block->i_pts || p_block->i_dts )
 519             {
 520                 mpeg2_tag_picture( p_sys->p_mpeg2dec,
 521                                    (uint32_t)p_block->i_pts,
 522                                    (uint32_t)p_block->i_dts );
 523 #endif
 524                 p_sys->i_previous_pts = p_sys->i_current_pts;
 525                 p_sys->i_current_pts = p_block->i_pts;
 526                 p_sys->i_previous_dts = p_sys->i_current_dts;
 527                 p_sys->i_current_dts = p_block->i_dts;
 528             }
 529
 530             mpeg2_buffer( p_sys->p_mpeg2dec, p_block->p_buffer,
 531                           p_block->p_buffer + p_block->i_buffer );
 532
 533             p_block->i_buffer = 0;
 534             break;
 535
 536 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
 537
 538         case STATE_SEQUENCE_MODIFIED:
 539             GetAR( p_dec );
 540             break;
 541 #endif
 542         case STATE_PICTURE_2ND:
 543             p_sys->b_second_field = true;
 544             break;
 545
 546
 547         case STATE_INVALID_END:
 548         case STATE_END:
 549         case STATE_SLICE:
 550             p_pic = NULL;
 551             if( p_sys->p_info->display_fbuf &&
 552                 p_sys->p_info->display_fbuf->id )
 553             {
 554                 p_pic = p_sys->p_info->display_fbuf->id;
 555                 if( DpbDisplayPicture( p_dec, p_pic ) )
 556                     p_pic = NULL;
 557
 558                 decoder_SynchroEnd( p_sys->p_synchro,
 559                                     p_sys->p_info->display_picture->flags & PIC_MASK_CODING_TYPE,
 560                                     p_sys->b_garbage_pic );
 561
 562                 if( p_pic )
 563                 {
 564                     p_pic->date = decoder_SynchroDate( p_sys->p_synchro );
 565                     if( p_sys->b_garbage_pic )
 566                         p_pic->date = 0; /* ??? */
 567                     p_sys->b_garbage_pic = false;
 568                 }
 569             }
 570
 571             if( p_sys->p_info->discard_fbuf &&
 572                 p_sys->p_info->discard_fbuf->id )
 573             {
 574                 DpbUnlinkPicture( p_dec, p_sys->p_info->discard_fbuf->id );
 575             }
 576
 577             /* For still frames */
 578             if( state == STATE_END && p_pic )
 579                 p_pic->b_force = true;
 580
 581             if( p_pic )
 582             {
 583                 /* Avoid frames with identical timestamps.
 584                  * Especially needed for still frames in DVD menus. */
 585                 if( p_sys->i_last_frame_pts == p_pic->date )
 586                     p_pic->date++;
 587                 p_sys->i_last_frame_pts = p_pic->date;
 588                 return p_pic;
 589             }
 590             break;
 591
 592         case STATE_INVALID:
 593         {
 594             msg_Err( p_dec, "invalid picture encountered" );
 595             /* I don't think we have anything to do, but well without
 596              * docs ... */
 597             break;
 598         }
 599
 600         default:
 601             break;
 602         }
 603     }
 604
 605     /* Never reached */
 606     return NULL;
 607 }
 608
 609 /*****************************************************************************
 610  * CloseDecoder: libmpeg2 decoder destruction
 611  *****************************************************************************/
 612 static void CloseDecoder( vlc_object_t *p_this )
 613 {
 614     decoder_t *p_dec = (decoder_t *)p_this;
 615     decoder_sys_t *p_sys = p_dec->p_sys;
 616
 617     DpbClean( p_dec );
 618
 619     free( p_sys->p_gop_user_data );
 620
 621     if( p_sys->p_synchro ) decoder_SynchroRelease( p_sys->p_synchro );
 622
 623     if( p_sys->p_mpeg2dec ) mpeg2_close( p_sys->p_mpeg2dec );
 624
 625     free( p_sys );
 626 }
 627
 628 /*****************************************************************************
 629  * Reset: reset the decoder state
 630  *****************************************************************************/
 631 static void Reset( decoder_t *p_dec )
 632 {
 633     decoder_sys_t *p_sys = p_dec->p_sys;
 634
 635     cc_Flush( &p_sys->cc );
 636     mpeg2_reset( p_sys->p_mpeg2dec, 0 );
 637     DpbClean( p_dec );
 638 }
 639
 640 /*****************************************************************************
 641  * GetNewPicture: Get a new picture from the vout and set the buf struct
 642  *****************************************************************************/
 643 static picture_t *GetNewPicture( decoder_t *p_dec )
 644 {
 645     decoder_sys_t *p_sys = p_dec->p_sys;
 646     picture_t *p_pic;
 647
 648     p_dec->fmt_out.video.i_width = p_sys->p_info->sequence->width;
 649     p_dec->fmt_out.video.i_visible_width =
 650         p_sys->p_info->sequence->picture_width;
 651     p_dec->fmt_out.video.i_height = p_sys->p_info->sequence->height;
 652     p_dec->fmt_out.video.i_visible_height =
 653         p_sys->p_info->sequence->picture_height;
 654     p_dec->fmt_out.video.i_aspect = p_sys->i_aspect;
 655     p_dec->fmt_out.video.i_sar_num = p_sys->i_sar_num;
 656     p_dec->fmt_out.video.i_sar_den = p_sys->i_sar_den;
 657
 658     if( p_sys->p_info->sequence->frame_period > 0 )
 659     {
 660         p_dec->fmt_out.video.i_frame_rate =
 661             (uint32_t)( (uint64_t)1001000000 * 27 /
 662                         p_sys->p_info->sequence->frame_period );
 663         p_dec->fmt_out.video.i_frame_rate_base = 1001;
 664     }
 665
 666     p_dec->fmt_out.i_codec =
 667         ( p_sys->p_info->sequence->chroma_height <
 668           p_sys->p_info->sequence->height ) ?
 669         VLC_CODEC_I420 : VLC_CODEC_I422;
 670
 671     /* Get a new picture */
 672     p_pic = decoder_NewPicture( p_dec );
 673
 674     if( p_pic == NULL )
 675         return NULL;
 676
 677     p_pic->b_progressive = p_sys->p_info->current_picture != NULL ?
 678         p_sys->p_info->current_picture->flags & PIC_FLAG_PROGRESSIVE_FRAME : 1;
 679     p_pic->b_top_field_first = p_sys->p_info->current_picture != NULL ?
 680         p_sys->p_info->current_picture->flags & PIC_FLAG_TOP_FIELD_FIRST : 1;
 681     p_pic->i_nb_fields = p_sys->p_info->current_picture != NULL ?
 682         p_sys->p_info->current_picture->nb_fields : 2;
 683
 684     return p_pic;
 685 }
 686
 687 #if MPEG2_RELEASE >= MPEG2_VERSION (0, 5, 0)
 688 /*****************************************************************************
 689  * GetCc: Retrieves the Closed Captions for the CC decoder.
 690  *****************************************************************************/
 691 static block_t *GetCc( decoder_t *p_dec, bool pb_present[4] )
 692 {
 693     decoder_sys_t   *p_sys = p_dec->p_sys;
 694     block_t         *p_cc = NULL;
 695     int i;
 696
 697     for( i = 0; i < 4; i++ )
 698         pb_present[i] = p_sys->cc.pb_present[i];
 699
 700     if( p_sys->cc.i_data <= 0 )
 701         return NULL;
 702
 703     p_cc = block_New( p_dec, p_sys->cc.i_data);
 704     if( p_cc )
 705     {
 706         memcpy( p_cc->p_buffer, p_sys->cc.p_data, p_sys->cc.i_data );
 707         p_cc->i_dts =
 708         p_cc->i_pts = p_sys->cc.b_reorder ? p_sys->i_cc_pts : p_sys->i_cc_dts;
 709         p_cc->i_flags = ( p_sys->cc.b_reorder  ? p_sys->i_cc_flags : BLOCK_FLAG_TYPE_P ) & ( BLOCK_FLAG_TYPE_I|BLOCK_FLAG_TYPE_P|BLOCK_FLAG_TYPE_B);
 710     }
 711     cc_Flush( &p_sys->cc );
 712     return p_cc;
 713 }
 714 #endif
 715
 716 /*****************************************************************************
 717  * GetAR: Get aspect ratio
 718  *****************************************************************************/
 719 static void GetAR( decoder_t *p_dec )
 720 {
 721     decoder_sys_t *p_sys = p_dec->p_sys;
 722     int i_old_aspect = p_sys->i_aspect;
 723
 724     /* Check whether the input gave a particular aspect ratio */
 725     if( p_dec->fmt_in.video.i_aspect )
 726     {
 727         p_sys->i_aspect = p_dec->fmt_in.video.i_aspect;
 728     }
 729     else
 730     {
 731         /* Use the value provided in the MPEG sequence header */
 732         if( p_sys->p_info->sequence->pixel_height > 0 )
 733         {
 734             p_sys->i_aspect =
 735                 ((uint64_t)p_sys->p_info->sequence->picture_width) *
 736                 p_sys->p_info->sequence->pixel_width *
 737                 VOUT_ASPECT_FACTOR /
 738                 p_sys->p_info->sequence->picture_height /
 739                 p_sys->p_info->sequence->pixel_height;
 740             p_sys->i_sar_num = p_sys->p_info->sequence->pixel_width;
 741             p_sys->i_sar_den = p_sys->p_info->sequence->pixel_height;
 742         }
 743         else
 744         {
 745             /* Invalid aspect, assume 4:3.
 746              * This shouldn't happen and if it does it is a bug
 747              * in libmpeg2 (likely triggered by an invalid stream) */
 748             p_sys->i_aspect = VOUT_ASPECT_FACTOR * 4 / 3;
 749             p_sys->i_sar_num = p_sys->p_info->sequence->picture_height * 4;
 750             p_sys->i_sar_den = p_sys->p_info->sequence->picture_width * 3;
 751         }
 752     }
 753
 754     if( p_sys->i_aspect == i_old_aspect )
 755         return;
 756
 757     if( p_sys->p_info->sequence->frame_period > 0 )
 758         msg_Dbg( p_dec,
 759                  "%dx%d (display %d,%d), aspect %d, sar %i:%i, %u.%03u fps",
 760                  p_sys->p_info->sequence->picture_width,
 761                  p_sys->p_info->sequence->picture_height,
 762                  p_sys->p_info->sequence->display_width,
 763                  p_sys->p_info->sequence->display_height,
 764                  p_sys->i_aspect, p_sys->i_sar_num, p_sys->i_sar_den,
 765                  (uint32_t)((uint64_t)1001000000 * 27 /
 766                      p_sys->p_info->sequence->frame_period / 1001),
 767                  (uint32_t)((uint64_t)1001000000 * 27 /
 768                      p_sys->p_info->sequence->frame_period % 1001) );
 769     else
 770         msg_Dbg( p_dec, "bad frame period" );
 771 }
 772
 773 /*****************************************************************************
 774  * PutPicture: Put a picture_t in mpeg2 context
 775  *****************************************************************************/
 776 static void PutPicture( decoder_t *p_dec, picture_t *p_picture )
 777 {
 778     decoder_sys_t *p_sys = p_dec->p_sys;
 779
 780     /* */
 781     uint8_t *pp_buf[3];
 782     for( int j = 0; j < 3; j++ )
 783         pp_buf[j] = p_picture ? p_picture->p[j].p_pixels : NULL;
 784     mpeg2_set_buf( p_sys->p_mpeg2dec, pp_buf, p_picture );
 785
 786     /* Completly broken API, why the hell does it suppose
 787      * the stride of the chroma planes ! */
 788     if( p_picture )
 789         mpeg2_stride( p_sys->p_mpeg2dec, p_picture->p[Y_PLANE].i_pitch );
 790 }
 791
 792
 793 /**
 794  * Initialize a virtual Decoded Picture Buffer to workaround
 795  * libmpeg2 deficient API
 796  */
 797 static void DpbInit( decoder_t *p_dec )
 798 {
 799     decoder_sys_t *p_sys = p_dec->p_sys;
 800
 801     for( int i = 0; i < DPB_COUNT; i++ )
 802         p_sys->p_dpb[i].p_picture = NULL;
 803 }
 804 /**
 805  * Empty and reset the current DPB
 806  */
 807 static void DpbClean( decoder_t *p_dec )
 808 {
 809     decoder_sys_t *p_sys = p_dec->p_sys;
 810
 811     for( int i = 0; i < DPB_COUNT; i++ )
 812     {
 813         picture_dpb_t *p = &p_sys->p_dpb[i];
 814         if( !p->p_picture )
 815             continue;
 816         if( p->b_linked )
 817             decoder_UnlinkPicture( p_dec, p->p_picture );
 818         if( !p->b_displayed )
 819             decoder_DeletePicture( p_dec, p->p_picture );
 820
 821         p->p_picture = NULL;
 822     }
 823 }
 824 /**
 825  * Retreive a picture and reserve a place in the DPB
 826  */
 827 static picture_t *DpbNewPicture( decoder_t *p_dec )
 828 {
 829     decoder_sys_t *p_sys = p_dec->p_sys;
 830
 831     picture_dpb_t *p;
 832     int i;
 833
 834     for( i = 0; i < DPB_COUNT; i++ )
 835     {
 836         p = &p_sys->p_dpb[i];
 837         if( !p->p_picture )
 838             break;
 839     }
 840     if( i >= DPB_COUNT )
 841     {
 842         msg_Err( p_dec, "Leaking picture" );
 843         return NULL;
 844     }
 845
 846     p->p_picture = GetNewPicture( p_dec );
 847     if( p->p_picture )
 848     {
 849         decoder_LinkPicture( p_dec, p->p_picture );
 850         p->b_linked = true;
 851         p->b_displayed = false;
 852
 853         p->p_picture->date = 0;
 854     }
 855     return p->p_picture;
 856 }
 857 static picture_dpb_t *DpbFindPicture( decoder_t *p_dec, picture_t *p_picture )
 858 {
 859     decoder_sys_t *p_sys = p_dec->p_sys;
 860
 861     for( int i = 0; i < DPB_COUNT; i++ )
 862     {
 863         picture_dpb_t *p = &p_sys->p_dpb[i];
 864         if( p->p_picture == p_picture )
 865             return p;
 866     }
 867     return NULL;
 868 }
 869 /**
 870  * Unlink the provided picture and ensure that the decoder
 871  * does not own it anymore.
 872  */
 873 static void DpbUnlinkPicture( decoder_t *p_dec, picture_t *p_picture )
 874 {
 875     picture_dpb_t *p = DpbFindPicture( p_dec, p_picture );
 876
 877     /* XXX it is needed to workaround libmpeg2 bugs */
 878     if( !p || !p->b_linked )
 879     {
 880         msg_Err( p_dec, "DpbUnlinkPicture called on an invalid picture" );
 881         return;
 882     }
 883
 884     assert( p && p->b_linked );
 885
 886     decoder_UnlinkPicture( p_dec, p->p_picture );
 887     p->b_linked = false;
 888
 889     if( !p->b_displayed )
 890         decoder_DeletePicture( p_dec, p->p_picture );
 891     p->p_picture = NULL;
 892 }
 893 /**
 894  * Mark the provided picture as displayed.
 895  */
 896 static int DpbDisplayPicture( decoder_t *p_dec, picture_t *p_picture )
 897 {
 898     picture_dpb_t *p = DpbFindPicture( p_dec, p_picture );
 899
 900     /* XXX it is needed to workaround libmpeg2 bugs */
 901     if( !p || p->b_displayed || !p->b_linked )
 902     {
 903         msg_Err( p_dec, "DpbDisplayPicture called on an invalid picture" );
 904         return VLC_EGENERIC;
 905     }
 906
 907     assert( p && !p->b_displayed && p->b_linked );
 908
 909     p->b_displayed = true;
 910     return VLC_SUCCESS;
 911 }
 912
 913