git.sesse.net Git - vlc/blob - plugins/mpeg_vdec/vpar_synchro.c

   1 /*****************************************************************************
   2  * vpar_synchro.c : frame dropping routines
   3  *****************************************************************************
   4  * Copyright (C) 1999-2001 VideoLAN
   5  * $Id: vpar_synchro.c,v 1.4 2001/12/10 04:53:11 sam Exp $
   6  *
   7  * Authors: Christophe Massiot <massiot@via.ecp.fr>
   8  *          Samuel Hocevar <sam@via.ecp.fr>
   9  *          Jean-Marc Dressler <polux@via.ecp.fr>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  24  *****************************************************************************/
  25
  26 /*
  27  * DISCUSSION : How to Write an efficient Frame-Dropping Algorithm
  28  * ==========
  29  *
  30  * This implementation is based on mathematical and statistical
  31  * developments. Older implementations used an enslavement, considering
  32  * that if we're late when reading an I picture, we will decode one frame
  33  * less. It had a tendancy to derive, and wasn't responsive enough, which
  34  * would have caused trouble with the stream control stuff.
  35  *
  36  * 1. Structure of a picture stream
  37  *    =============================
  38  * Between 2 I's, we have for instance :
  39  *    I   B   P   B   P   B   P   B   P   B   P   B   I
  40  *    t0  t1  t2  t3  t4  t5  t6  t7  t8  t9  t10 t11 t12
  41  * Please bear in mind that B's and IP's will be inverted when displaying
  42  * (decoding order != presentation order). Thus, t1 < t0.
  43  *
  44  * 2. Definitions
  45  *    ===========
  46  * t[0..12]     : Presentation timestamps of pictures 0..12.
  47  * t            : Current timestamp, at the moment of the decoding.
  48  * T            : Picture period, T = 1/frame_rate.
  49  * tau[I,P,B]   : Mean time to decode an [I,P,B] picture.
  50  * tauYUV       : Mean time to render a picture (given by the video_output).
  51  * tau´[I,P,B] = 2 * tau[I,P,B] + tauYUV
  52  *              : Mean time + typical difference (estimated to tau/2, that
  53  *                needs to be confirmed) + render time.
  54  * DELTA        : A given error margin.
  55  *
  56  * 3. General considerations
  57  *    ======================
  58  * We define three types of machines :
  59  *      14T > tauI : machines capable of decoding all I pictures
  60  *      2T > tauP  : machines capable of decoding all P pictures
  61  *      T > tauB   : machines capable of decoding all B pictures
  62  *
  63  * 4. Decoding of an I picture
  64  *    ========================
  65  * On fast machines, we decode all I's.
  66  * Otherwise :
  67  * We can decode an I picture if we simply have enough time to decode it
  68  * before displaying :
  69  *      t0 - t > tau´I + DELTA
  70  *
  71  * 5. Decoding of a P picture
  72  *    =======================
  73  * On fast machines, we decode all P's.
  74  * Otherwise :
  75  * First criterion : have time to decode it.
  76  *      t2 - t > tau´P + DELTA
  77  *
  78  * Second criterion : it shouldn't prevent us from displaying the forthcoming
  79  * I picture, which is more important.
  80  *      t12 - t > tau´P + tau´I + DELTA
  81  *
  82  * 6. Decoding of a B picture
  83  *    =======================
  84  * On fast machines, we decode all B's. Otherwise :
  85  *      t1 - t > tau´B + DELTA
  86  * Since the next displayed I or P is already decoded, we don't have to
  87  * worry about it.
  88  *
  89  * I hope you will have a pleasant flight and do not forget your life
  90  * jacket.
  91  *                                                  --Meuuh (2000-12-29)
  92  */
  93
  94 /*****************************************************************************
  95  * Preamble
  96  *****************************************************************************/
  97 #include "defs.h"
  98
  99 #include <string.h>                                    /* memcpy(), memset() */
 100
 101 #include "common.h"
 102 #include "intf_msg.h"
 103 #include "threads.h"
 104 #include "mtime.h"
 105
 106 #include "video.h"
 107 #include "video_output.h"
 108
 109 #include "stream_control.h"
 110 #include "input_ext-dec.h"
 111
 112 #include "vdec_ext-plugins.h"
 113 #include "vpar_pool.h"
 114 #include "video_parser.h"
 115
 116 #include "modules_export.h"
 117
 118 /*
 119  * Local prototypes
 120  */
 121 static int  SynchroType( void );
 122
 123 /* Error margins */
 124 #define DELTA                   (int)(0.075*CLOCK_FREQ)
 125
 126 #define DEFAULT_NB_P            5
 127 #define DEFAULT_NB_B            1
 128
 129 /*****************************************************************************
 130  * vpar_SynchroInit : You know what ?
 131  *****************************************************************************/
 132 void vpar_SynchroInit( vpar_thread_t * p_vpar )
 133 {
 134     p_vpar->synchro.i_type = SynchroType();
 135
 136     /* We use a fake stream pattern, which is often right. */
 137     p_vpar->synchro.i_n_p = p_vpar->synchro.i_eta_p = DEFAULT_NB_P;
 138     p_vpar->synchro.i_n_b = p_vpar->synchro.i_eta_b = DEFAULT_NB_B;
 139     memset( p_vpar->synchro.p_tau, 0, 4 * sizeof(mtime_t) );
 140     memset( p_vpar->synchro.pi_meaningful, 0, 4 * sizeof(unsigned int) );
 141     p_vpar->synchro.b_dropped_last = 0;
 142     p_vpar->synchro.current_pts = mdate() + DEFAULT_PTS_DELAY;
 143     p_vpar->synchro.backward_pts = 0;
 144     p_vpar->synchro.i_current_period = p_vpar->synchro.i_backward_period = 0;
 145     p_vpar->synchro.i_trashed_pic = p_vpar->synchro.i_not_chosen_pic =
 146         p_vpar->synchro.i_pic = 0;
 147 }
 148
 149 /*****************************************************************************
 150  * vpar_SynchroChoose : Decide whether we will decode a picture or not
 151  *****************************************************************************/
 152 boolean_t vpar_SynchroChoose( vpar_thread_t * p_vpar, int i_coding_type,
 153                               int i_structure )
 154 {
 155     /* For clarity reasons, we separated the special synchros code from the
 156      * mathematical synchro */
 157
 158     if( p_vpar->synchro.i_type != VPAR_SYNCHRO_DEFAULT )
 159     {
 160         switch( i_coding_type )
 161         {
 162         case I_CODING_TYPE:
 163             /* I, IP, IP+, IPB */
 164             if( p_vpar->synchro.i_type == VPAR_SYNCHRO_Iplus )
 165             {
 166                 p_vpar->synchro.b_dropped_last = 1;
 167             }
 168             return( 1 );
 169
 170         case P_CODING_TYPE:
 171             if( p_vpar->synchro.i_type == VPAR_SYNCHRO_I ) /* I */
 172             {
 173                 return( 0 );
 174             }
 175
 176             if( p_vpar->synchro.i_type == VPAR_SYNCHRO_Iplus ) /* I+ */
 177             {
 178                 if( p_vpar->synchro.b_dropped_last )
 179                 {
 180                     p_vpar->synchro.b_dropped_last = 0;
 181                     return( 1 );
 182                 }
 183                 else
 184                 {
 185                     return( 0 );
 186                 }
 187             }
 188
 189             return( 1 ); /* IP, IP+, IPB */
 190
 191         case B_CODING_TYPE:
 192             if( p_vpar->synchro.i_type <= VPAR_SYNCHRO_IP ) /* I, IP */
 193             {
 194                 return( 0 );
 195             }
 196             else if( p_vpar->synchro.i_type == VPAR_SYNCHRO_IPB ) /* IPB */
 197             {
 198                 return( 1 );
 199             }
 200
 201             p_vpar->synchro.b_dropped_last ^= 1; /* IP+ */
 202             return( !p_vpar->synchro.b_dropped_last );
 203         }
 204         return( 0 ); /* never reached but gcc yells at me */
 205     }
 206     else
 207     {
 208 #define TAU_PRIME( coding_type )    (p_vpar->synchro.p_tau[(coding_type)] \
 209                                  + (p_vpar->synchro.p_tau[(coding_type)] >> 1) \
 210                                             + tau_yuv)
 211 #define S                           p_vpar->synchro
 212         /* VPAR_SYNCHRO_DEFAULT */
 213         mtime_t         now, period, tau_yuv;
 214         mtime_t         pts = 0;
 215         boolean_t       b_decode = 0;
 216 #ifdef TRACE_VPAR
 217         char            p_date[MSTRTIME_MAX_SIZE];
 218 #endif
 219
 220         now = mdate();
 221         period = 1000000 * 1001 / p_vpar->sequence.i_frame_rate
 222                     * p_vpar->sequence.i_current_rate / DEFAULT_RATE;
 223
 224         vlc_mutex_lock( &p_vpar->p_vout->change_lock );
 225         tau_yuv = p_vpar->p_vout->render_time;
 226         vlc_mutex_unlock( &p_vpar->p_vout->change_lock );
 227
 228         switch( i_coding_type )
 229         {
 230         case I_CODING_TYPE:
 231             if( S.backward_pts )
 232             {
 233                 pts = S.backward_pts;
 234             }
 235             else
 236             {
 237                 /* displaying order : B B P B B I
 238                  *                      ^       ^
 239                  *                      |       +- current picture
 240                  *                      +- current PTS
 241                  */
 242                 pts = S.current_pts + period * (S.i_n_b + 2);
 243             }
 244
 245             if( (1 + S.i_n_p * (S.i_n_b + 1)) * period >
 246                     S.p_tau[I_CODING_TYPE] )
 247             {
 248                 b_decode = 1;
 249             }
 250             else
 251             {
 252                 b_decode = (pts - now) > (TAU_PRIME(I_CODING_TYPE) + DELTA);
 253             }
 254             if( !b_decode )
 255                 intf_WarnMsg( 1, "vpar synchro warning: trashing I (%lld)",
 256                              pts - now);
 257             break;
 258
 259         case P_CODING_TYPE:
 260             if( S.backward_pts )
 261             {
 262                 pts = S.backward_pts;
 263             }
 264             else
 265             {
 266                 pts = S.current_pts + period * (S.i_n_b + 1);
 267             }
 268
 269             if( (1 + S.i_n_p * (S.i_n_b + 1)) * period >
 270                     S.p_tau[I_CODING_TYPE] )
 271             {
 272                 if( (S.i_n_b + 1) * period > S.p_tau[P_CODING_TYPE] )
 273                 {
 274                     /* Security in case we're _really_ late */
 275                     b_decode = (pts - now > 0);
 276                 }
 277                 else
 278                 {
 279                     b_decode = (pts - now) > (TAU_PRIME(P_CODING_TYPE) + DELTA);
 280                     /* next I */
 281                     b_decode &= (pts - now
 282                                   + period
 283                               * ( (S.i_n_p - S.i_eta_p) * (1 + S.i_n_b) - 1 ))
 284                                 > (TAU_PRIME(P_CODING_TYPE)
 285                                     + TAU_PRIME(I_CODING_TYPE) + DELTA);
 286                 }
 287             }
 288             else
 289             {
 290                 b_decode = 0;
 291             }
 292             break;
 293
 294         case B_CODING_TYPE:
 295             pts = S.current_pts;
 296
 297             if( (S.i_n_b + 1) * period > S.p_tau[P_CODING_TYPE] )
 298             {
 299                 b_decode = (pts - now) > (TAU_PRIME(B_CODING_TYPE) + DELTA);
 300             }
 301             else
 302             {
 303                 b_decode = 0;
 304             }
 305         }
 306
 307 #ifdef TRACE_VPAR
 308         intf_DbgMsg("vpar synchro debug: %s picture scheduled for %s, %s (%lld)",
 309                     i_coding_type == B_CODING_TYPE ? "B" :
 310                     (i_coding_type == P_CODING_TYPE ? "P" : "I"),
 311                     mstrtime(p_date, pts), b_decode ? "decoding" : "trashed",
 312                     S.p_tau[i_coding_type]);
 313 #endif
 314         if( !b_decode )
 315         {
 316             S.i_not_chosen_pic++;
 317         }
 318         return( b_decode );
 319 #undef S
 320 #undef TAU_PRIME
 321     }
 322 }
 323
 324 /*****************************************************************************
 325  * vpar_SynchroTrash : Update counters when we trash a picture
 326  *****************************************************************************/
 327 void vpar_SynchroTrash( vpar_thread_t * p_vpar, int i_coding_type,
 328                         int i_structure )
 329 {
 330     p_vpar->synchro.i_trashed_pic++;
 331 }
 332
 333 /*****************************************************************************
 334  * vpar_SynchroDecode : Update timers when we decide to decode a picture
 335  *****************************************************************************/
 336 void vpar_SynchroDecode( vpar_thread_t * p_vpar, int i_coding_type,
 337                          int i_structure )
 338 {
 339     p_vpar->synchro.decoding_start = mdate();
 340 }
 341
 342 /*****************************************************************************
 343  * vpar_SynchroEnd : Called when the image is totally decoded
 344  *****************************************************************************/
 345 void vpar_SynchroEnd( vpar_thread_t * p_vpar, int i_coding_type,
 346                       int i_structure, int i_garbage )
 347 {
 348     mtime_t     tau;
 349
 350     if( !i_garbage )
 351     {
 352         tau = mdate() - p_vpar->synchro.decoding_start;
 353
 354         /* If duration too high, something happened (pause ?), so don't
 355          * take it into account. */
 356         if( tau < 3 * p_vpar->synchro.p_tau[i_coding_type]
 357              || !p_vpar->synchro.pi_meaningful[i_coding_type] )
 358         {
 359             /* Mean with average tau, to ensure stability. */
 360             p_vpar->synchro.p_tau[i_coding_type] =
 361                 (p_vpar->synchro.pi_meaningful[i_coding_type]
 362                  * p_vpar->synchro.p_tau[i_coding_type] + tau)
 363                 / (p_vpar->synchro.pi_meaningful[i_coding_type] + 1);
 364             if( p_vpar->synchro.pi_meaningful[i_coding_type] < MAX_PIC_AVERAGE )
 365             {
 366                 p_vpar->synchro.pi_meaningful[i_coding_type]++;
 367             }
 368         }
 369
 370 #ifdef TRACE_VPAR
 371         intf_DbgMsg("vpar synchro debug: finished decoding %s (%lld)",
 372                     i_coding_type == B_CODING_TYPE ? "B" :
 373                     (i_coding_type == P_CODING_TYPE ? "P" : "I"), tau);
 374 #endif
 375     }
 376     else
 377     {
 378         intf_DbgMsg("vpar synchro debug: aborting %s",
 379                     i_coding_type == B_CODING_TYPE ? "B" :
 380                     (i_coding_type == P_CODING_TYPE ? "P" : "I"));
 381     }
 382 }
 383
 384 /*****************************************************************************
 385  * vpar_SynchroDate : When an image has been decoded, ask for its date
 386  *****************************************************************************/
 387 mtime_t vpar_SynchroDate( vpar_thread_t * p_vpar )
 388 {
 389     /* No need to lock, since PTS are only used by the video parser. */
 390     return( p_vpar->synchro.current_pts );
 391 }
 392
 393 /*****************************************************************************
 394  * vpar_SynchroNewPicture: Update stream structure and PTS
 395  *****************************************************************************/
 396 void vpar_SynchroNewPicture( vpar_thread_t * p_vpar, int i_coding_type,
 397                              int i_repeat_field )
 398 {
 399     mtime_t         period = 1000000 * 1001 / p_vpar->sequence.i_frame_rate
 400                               * p_vpar->sequence.i_current_rate / DEFAULT_RATE;
 401 #if 0
 402     mtime_t         now = mdate();
 403 #endif
 404
 405     switch( i_coding_type )
 406     {
 407     case I_CODING_TYPE:
 408         if( p_vpar->synchro.i_eta_p
 409              && p_vpar->synchro.i_eta_p != p_vpar->synchro.i_n_p )
 410         {
 411             intf_WarnMsg( 3, "vpar info: stream periodicity changed "
 412                           "from P[%d] to P[%d]",
 413                           p_vpar->synchro.i_n_p, p_vpar->synchro.i_eta_p );
 414             p_vpar->synchro.i_n_p = p_vpar->synchro.i_eta_p;
 415         }
 416         p_vpar->synchro.i_eta_p = p_vpar->synchro.i_eta_b = 0;
 417
 418         if( p_main->b_stats && p_vpar->synchro.i_type == VPAR_SYNCHRO_DEFAULT )
 419         {
 420             intf_Msg( "vpar synchro stats: I(%lld) P(%lld)[%d] B(%lld)[%d] YUV(%lld) : trashed %d:%d/%d",
 421                   p_vpar->synchro.p_tau[I_CODING_TYPE],
 422                   p_vpar->synchro.p_tau[P_CODING_TYPE],
 423                   p_vpar->synchro.i_n_p,
 424                   p_vpar->synchro.p_tau[B_CODING_TYPE],
 425                   p_vpar->synchro.i_n_b,
 426                   p_vpar->p_vout->render_time,
 427                   p_vpar->synchro.i_not_chosen_pic,
 428                   p_vpar->synchro.i_trashed_pic -
 429                   p_vpar->synchro.i_not_chosen_pic,
 430                   p_vpar->synchro.i_pic );
 431             p_vpar->synchro.i_trashed_pic = p_vpar->synchro.i_not_chosen_pic
 432                 = p_vpar->synchro.i_pic = 0;
 433         }
 434         break;
 435
 436     case P_CODING_TYPE:
 437         p_vpar->synchro.i_eta_p++;
 438         if( p_vpar->synchro.i_eta_b
 439              && p_vpar->synchro.i_eta_b != p_vpar->synchro.i_n_b )
 440         {
 441             intf_WarnMsg( 3, "vpar info: stream periodicity changed "
 442                           "from B[%d] to B[%d]",
 443                           p_vpar->synchro.i_n_b, p_vpar->synchro.i_eta_b );
 444             p_vpar->synchro.i_n_b = p_vpar->synchro.i_eta_b;
 445         }
 446         p_vpar->synchro.i_eta_b = 0;
 447         break;
 448     case B_CODING_TYPE:
 449         p_vpar->synchro.i_eta_b++;
 450         break;
 451     }
 452
 453     p_vpar->synchro.current_pts += p_vpar->synchro.i_current_period
 454                                         * (period >> 1);
 455
 456 #define PTS_THRESHOLD   (period >> 2)
 457     if( i_coding_type == B_CODING_TYPE )
 458     {
 459         /* A video frame can be displayed 1, 2 or 3 times, according to
 460          * repeat_first_field, top_field_first, progressive_sequence and
 461          * progressive_frame. */
 462         p_vpar->synchro.i_current_period = i_repeat_field;
 463
 464         if( p_vpar->sequence.next_pts )
 465         {
 466             if( p_vpar->sequence.next_pts - p_vpar->synchro.current_pts
 467                     > PTS_THRESHOLD
 468                  || p_vpar->synchro.current_pts - p_vpar->sequence.next_pts
 469                     > PTS_THRESHOLD )
 470             {
 471                 intf_WarnMsg( 2,
 472                         "vpar synchro warning: pts != current_date (%lld)",
 473                         p_vpar->synchro.current_pts
 474                             - p_vpar->sequence.next_pts );
 475             }
 476             p_vpar->synchro.current_pts = p_vpar->sequence.next_pts;
 477             p_vpar->sequence.next_pts = 0;
 478         }
 479     }
 480     else
 481     {
 482         p_vpar->synchro.i_current_period = p_vpar->synchro.i_backward_period;
 483         p_vpar->synchro.i_backward_period = i_repeat_field;
 484
 485         if( p_vpar->synchro.backward_pts )
 486         {
 487             if( p_vpar->sequence.next_dts &&
 488                 (p_vpar->sequence.next_dts - p_vpar->synchro.backward_pts
 489                     > PTS_THRESHOLD
 490               || p_vpar->synchro.backward_pts - p_vpar->sequence.next_dts
 491                     > PTS_THRESHOLD) )
 492             {
 493                 intf_WarnMsg( 2,
 494                         "vpar synchro warning: backward_pts != dts (%lld)",
 495                         p_vpar->sequence.next_dts
 496                             - p_vpar->synchro.backward_pts );
 497             }
 498             if( p_vpar->synchro.backward_pts - p_vpar->synchro.current_pts
 499                     > PTS_THRESHOLD
 500                  || p_vpar->synchro.current_pts - p_vpar->synchro.backward_pts
 501                     > PTS_THRESHOLD )
 502             {
 503                 intf_WarnMsg( 2,
 504                    "vpar synchro warning: backward_pts != current_pts (%lld)",
 505                    p_vpar->synchro.current_pts - p_vpar->synchro.backward_pts );
 506             }
 507             p_vpar->synchro.current_pts = p_vpar->synchro.backward_pts;
 508             p_vpar->synchro.backward_pts = 0;
 509         }
 510         else if( p_vpar->sequence.next_dts )
 511         {
 512             if( p_vpar->sequence.next_dts - p_vpar->synchro.current_pts
 513                     > PTS_THRESHOLD
 514                  || p_vpar->synchro.current_pts - p_vpar->sequence.next_dts
 515                     > PTS_THRESHOLD )
 516             {
 517                 intf_WarnMsg( 2,
 518                         "vpar synchro warning: dts != current_pts (%lld)",
 519                         p_vpar->synchro.current_pts
 520                             - p_vpar->sequence.next_dts );
 521             }
 522             /* By definition of a DTS. */
 523             p_vpar->synchro.current_pts = p_vpar->sequence.next_dts;
 524             p_vpar->sequence.next_dts = 0;
 525         }
 526
 527         if( p_vpar->sequence.next_pts )
 528         {
 529             /* Store the PTS for the next time we have to date an I picture. */
 530             p_vpar->synchro.backward_pts = p_vpar->sequence.next_pts;
 531             p_vpar->sequence.next_pts = 0;
 532         }
 533     }
 534 #undef PTS_THRESHOLD
 535
 536 #if 0
 537     /* Removed for incompatibility with slow motion */
 538     if( p_vpar->synchro.current_pts + DEFAULT_PTS_DELAY < now )
 539     {
 540         /* We cannot be _that_ late, something must have happened, reinit
 541          * the dates. */
 542         intf_WarnMsg( 2, "PTS << now (%lld), resetting",
 543                       now - p_vpar->synchro.current_pts - DEFAULT_PTS_DELAY );
 544         p_vpar->synchro.current_pts = now + DEFAULT_PTS_DELAY;
 545     }
 546     if( p_vpar->synchro.backward_pts
 547          && p_vpar->synchro.backward_pts + DEFAULT_PTS_DELAY < now )
 548     {
 549         /* The same. */
 550         p_vpar->synchro.backward_pts = 0;
 551     }
 552 #endif
 553
 554     p_vpar->synchro.i_pic++;
 555 }
 556
 557 /*****************************************************************************
 558  * SynchroType: Get the user's synchro type
 559  *****************************************************************************
 560  * This function is called at initialization.
 561  *****************************************************************************/
 562 static int SynchroType( void )
 563 {
 564     char * psz_synchro = main_GetPszVariable( VPAR_SYNCHRO_VAR, NULL );
 565
 566     if( psz_synchro == NULL )
 567     {
 568         return VPAR_SYNCHRO_DEFAULT;
 569     }
 570
 571     switch( *psz_synchro++ )
 572     {
 573       case 'i':
 574       case 'I':
 575         switch( *psz_synchro++ )
 576         {
 577           case '\0':
 578             return VPAR_SYNCHRO_I;
 579
 580           case '+':
 581             if( *psz_synchro ) return 0;
 582             return VPAR_SYNCHRO_Iplus;
 583
 584           case 'p':
 585           case 'P':
 586             switch( *psz_synchro++ )
 587             {
 588               case '\0':
 589                 return VPAR_SYNCHRO_IP;
 590
 591               case '+':
 592                 if( *psz_synchro ) return 0;
 593                 return VPAR_SYNCHRO_IPplus;
 594
 595               case 'b':
 596               case 'B':
 597                 if( *psz_synchro ) return 0;
 598                 return VPAR_SYNCHRO_IPB;
 599
 600               default:
 601                 return VPAR_SYNCHRO_DEFAULT;
 602
 603             }
 604
 605           default:
 606             return VPAR_SYNCHRO_DEFAULT;
 607         }
 608     }
 609
 610     return VPAR_SYNCHRO_DEFAULT;
 611 }
 612