git.sesse.net Git - vlc/blob - src/video_parser/vpar_synchro.c

   1 /*****************************************************************************
   2  * vpar_synchro.c : frame dropping routines
   3  *****************************************************************************
   4  * Copyright (C) 1999, 2000 VideoLAN
   5  * $Id: vpar_synchro.c,v 1.73 2001/01/15 18:02:49 massiot 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  * FIXME: write a few words about stream structure changes.
  45  *
  46  * 2. Definitions
  47  *    ===========
  48  * t[0..12]     : Presentation timestamps of pictures 0..12.
  49  * t            : Current timestamp, at the moment of the decoding.
  50  * T            : Picture period, T = 1/frame_rate.
  51  * tau[I,P,B]   : Mean time to decode an [I,P,B] picture.
  52  * tauYUV       : Mean time to render a picture (given by the video_output).
  53  * tau´[I,P,B] = 2 * tau[I,P,B] + tauYUV
  54  *              : Mean time + typical difference (estimated to tau/2, that
  55  *                needs to be confirmed) + render time.
  56  * DELTA        : A given error margin.
  57  *
  58  * 3. General considerations
  59  *    ======================
  60  * We define three types of machines :
  61  *      14T > tauI : machines capable of decoding all I pictures
  62  *      2T > tauP  : machines capable of decoding all P pictures
  63  *      T > tauB   : machines capable of decoding all B pictures
  64  *
  65  * 4. Decoding of an I picture
  66  *    ========================
  67  * On fast machines, we decode all I's.
  68  * Otherwise :
  69  * We can decode an I picture if we simply have enough time to decode it
  70  * before displaying :
  71  *      t0 - t > tau´I + DELTA
  72  *
  73  * 5. Decoding of a P picture
  74  *    =======================
  75  * On fast machines, we decode all P's.
  76  * Otherwise :
  77  * First criterion : have time to decode it.
  78  *      t2 - t > tau´P + DELTA
  79  *
  80  * Second criterion : it shouldn't prevent us from displaying the forthcoming
  81  * I picture, which is more important.
  82  *      t12 - t > tau´P + tau´I + DELTA
  83  *
  84  * 6. Decoding of a B picture
  85  *    =======================
  86  * On fast machines, we decode all B's. Otherwise :
  87  *      t1 - t > tau´B + DELTA
  88  * Since the next displayed I or P is already decoded, we don't have to
  89  * worry about it.
  90  *
  91  * I hope you will have a pleasant flight and do not forget your life
  92  * jacket.
  93  *                                                  --Meuuh (2000-12-29)
  94  */
  95
  96 /*****************************************************************************
  97  * Preamble
  98  *****************************************************************************/
  99 #include "defs.h"
 100
 101 #include "config.h"
 102 #include "common.h"
 103 #include "threads.h"
 104 #include "mtime.h"
 105 #include "plugins.h"
 106
 107 #include "intf_msg.h"
 108
 109 #include "stream_control.h"
 110 #include "input_ext-dec.h"
 111
 112 #include "video.h"
 113 #include "video_output.h"
 114
 115 #include "video_decoder.h"
 116 #include "../video_decoder/vdec_idct.h"
 117 #include "../video_decoder/vdec_motion.h"
 118
 119 #include "../video_decoder/vpar_blocks.h"
 120 #include "../video_decoder/vpar_headers.h"
 121 #include "../video_decoder/vpar_synchro.h"
 122 #include "../video_decoder/video_parser.h"
 123
 124 #include "main.h"
 125
 126 /*
 127  * Local prototypes
 128  */
 129 static int  SynchroType( void );
 130
 131 /* Error margins */
 132 #define DELTA                   (int)(0.040*CLOCK_FREQ)
 133
 134 #define DEFAULT_NB_P            5
 135 #define DEFAULT_NB_B            1
 136
 137 /*****************************************************************************
 138  * vpar_SynchroInit : You know what ?
 139  *****************************************************************************/
 140 void vpar_SynchroInit( vpar_thread_t * p_vpar )
 141 {
 142     p_vpar->synchro.i_type = SynchroType();
 143     p_vpar->synchro.i_start = p_vpar->synchro.i_end = 0;
 144     vlc_mutex_init( &p_vpar->synchro.fifo_lock );
 145
 146     /* We use a fake stream pattern, which is often right. */
 147     p_vpar->synchro.i_n_p = p_vpar->synchro.i_eta_p = DEFAULT_NB_P;
 148     p_vpar->synchro.i_n_b = p_vpar->synchro.i_eta_b = DEFAULT_NB_B;
 149     memset( p_vpar->synchro.p_tau, 0, 4 * sizeof(mtime_t) );
 150     memset( p_vpar->synchro.pi_meaningful, 0, 4 * sizeof(unsigned int) );
 151     p_vpar->synchro.b_dropped_last = 0;
 152     p_vpar->synchro.current_pts = mdate() + DEFAULT_PTS_DELAY;
 153     p_vpar->synchro.backward_pts = p_vpar->synchro.next_period = 0;
 154 #ifdef STATS
 155     p_vpar->synchro.i_trashed_pic = p_vpar->synchro.i_not_chosen_pic =
 156         p_vpar->synchro.i_pic = 0;
 157 #endif
 158 }
 159
 160 /*****************************************************************************
 161  * vpar_SynchroChoose : Decide whether we will decode a picture or not
 162  *****************************************************************************/
 163 boolean_t vpar_SynchroChoose( vpar_thread_t * p_vpar, int i_coding_type,
 164                               int i_structure )
 165 {
 166     /* For clarity reasons, we separated the special synchros code from the
 167      * mathematical synchro */
 168
 169     if( p_vpar->synchro.i_type != VPAR_SYNCHRO_DEFAULT )
 170     {
 171         switch( i_coding_type )
 172         {
 173         case I_CODING_TYPE:
 174             /* I, IP, IP+, IPB */
 175             if( p_vpar->synchro.i_type == VPAR_SYNCHRO_Iplus )
 176             {
 177                 p_vpar->synchro.b_dropped_last = 1;
 178             }
 179             return( 1 );
 180
 181         case P_CODING_TYPE:
 182             if( p_vpar->synchro.i_type == VPAR_SYNCHRO_I ) /* I */
 183             {
 184                 return( 0 );
 185             }
 186
 187             if( p_vpar->synchro.i_type == VPAR_SYNCHRO_Iplus ) /* I+ */
 188             {
 189                 if( p_vpar->synchro.b_dropped_last )
 190                 {
 191                     p_vpar->synchro.b_dropped_last = 0;
 192                     return( 1 );
 193                 }
 194                 else
 195                 {
 196                     return( 0 );
 197                 }
 198             }
 199
 200             return( 1 ); /* IP, IP+, IPB */
 201
 202         case B_CODING_TYPE:
 203             if( p_vpar->synchro.i_type <= VPAR_SYNCHRO_IP ) /* I, IP */
 204             {
 205                 return( 0 );
 206             }
 207             else if( p_vpar->synchro.i_type == VPAR_SYNCHRO_IPB ) /* IPB */
 208             {
 209                 return( 1 );
 210             }
 211
 212             p_vpar->synchro.b_dropped_last ^= 1; /* IP+ */
 213             return( !p_vpar->synchro.b_dropped_last );
 214         }
 215         return( 0 ); /* never reached but gcc yells at me */
 216     }
 217     else
 218     {
 219 #define TAU_PRIME( coding_type )    (p_vpar->synchro.p_tau[(coding_type)] \
 220                                  + (p_vpar->synchro.p_tau[(coding_type)] >> 1) \
 221                                             + tau_yuv)
 222 #define S                           p_vpar->synchro
 223         /* VPAR_SYNCHRO_DEFAULT */
 224         mtime_t         now, pts, period, tau_yuv;
 225         boolean_t       b_decode = 0;
 226 #ifdef DEBUG_VPAR
 227         char            p_date[MSTRTIME_MAX_SIZE];
 228 #endif
 229
 230         now = mdate();
 231         period = 1000000 / (p_vpar->sequence.i_frame_rate) * 1001;
 232
 233         vlc_mutex_lock( &p_vpar->p_vout->change_lock );
 234         tau_yuv = p_vpar->p_vout->render_time;
 235         vlc_mutex_unlock( &p_vpar->p_vout->change_lock );
 236
 237         vlc_mutex_lock( &p_vpar->synchro.fifo_lock );
 238
 239         switch( i_coding_type )
 240         {
 241         case I_CODING_TYPE:
 242             if( S.backward_pts )
 243             {
 244                 pts = S.backward_pts;
 245             }
 246             else
 247             {
 248                 /* displaying order : B B P B B I
 249                  *                      ^       ^
 250                  *                      |       +- current picture
 251                  *                      +- current PTS
 252                  */
 253                 pts = S.current_pts + period * (S.i_n_b + 2);
 254             }
 255
 256             if( (1 + S.i_n_p * (S.i_n_b + 1)) * period >
 257                     S.p_tau[I_CODING_TYPE] )
 258             {
 259                 b_decode = 1;
 260             }
 261             else
 262             {
 263                 b_decode = (pts - now) > (TAU_PRIME(I_CODING_TYPE) + DELTA);
 264             }
 265             if( !b_decode )
 266                 intf_WarnMsg( 3, "vpar synchro warning: trashing I" );
 267             break;
 268
 269         case P_CODING_TYPE:
 270             if( S.backward_pts )
 271             {
 272                 pts = S.backward_pts;
 273             }
 274             else
 275             {
 276                 pts = S.current_pts + period * (S.i_n_b + 1);
 277             }
 278
 279             if( (1 + S.i_n_p * (S.i_n_b + 1)) * period >
 280                     S.p_tau[I_CODING_TYPE] )
 281             {
 282                 if( (S.i_n_b + 1) * period > S.p_tau[P_CODING_TYPE] )
 283                 {
 284                     /* Security in case we're _really_ late */
 285                     b_decode = (pts - now > 0);
 286                 }
 287                 else
 288                 {
 289                     b_decode = (pts - now) > (TAU_PRIME(P_CODING_TYPE) + DELTA);
 290                     /* next I */
 291                     b_decode &= (pts - now
 292                                   + period
 293                               * ( (S.i_n_p - S.i_eta_p) * (1 + S.i_n_b) - 1 ))
 294                                 > (TAU_PRIME(P_CODING_TYPE)
 295                                     + TAU_PRIME(I_CODING_TYPE) + DELTA);
 296                 }
 297             }
 298             else
 299             {
 300                 b_decode = 0;
 301             }
 302             break;
 303
 304         case B_CODING_TYPE:
 305             pts = S.current_pts;
 306
 307             if( (S.i_n_b + 1) * period > S.p_tau[P_CODING_TYPE] )
 308             {
 309                 b_decode = (pts - now) > (TAU_PRIME(B_CODING_TYPE) + DELTA);
 310             }
 311             else
 312             {
 313                 b_decode = 0;
 314             }
 315         }
 316
 317         vlc_mutex_unlock( &p_vpar->synchro.fifo_lock );
 318 #ifdef DEBUG_VPAR
 319         intf_DbgMsg("vpar synchro debug: %s picture scheduled for %s, %s (%lld)",
 320                     i_coding_type == B_CODING_TYPE ? "B" :
 321                     (i_coding_type == P_CODING_TYPE ? "P" : "I"),
 322                     mstrtime(p_date, pts), b_decode ? "decoding" : "trashed",
 323                     S.p_tau[i_coding_type]);
 324 #endif
 325 #ifdef STATS
 326         if( !b_decode )
 327         {
 328             S.i_not_chosen_pic++;
 329         }
 330 #endif
 331         return( b_decode );
 332 #undef S
 333 #undef TAU_PRIME
 334     }
 335 }
 336
 337 /*****************************************************************************
 338  * vpar_SynchroTrash : Update counters when we trash a picture
 339  *****************************************************************************/
 340 void vpar_SynchroTrash( vpar_thread_t * p_vpar, int i_coding_type,
 341                         int i_structure )
 342 {
 343 #ifdef STATS
 344     p_vpar->synchro.i_trashed_pic++;
 345 #endif
 346 }
 347
 348 /*****************************************************************************
 349  * vpar_SynchroDecode : Update timers when we decide to decode a picture
 350  *****************************************************************************/
 351 void vpar_SynchroDecode( vpar_thread_t * p_vpar, int i_coding_type,
 352                          int i_structure )
 353 {
 354     vlc_mutex_lock( &p_vpar->synchro.fifo_lock );
 355
 356     if( ((p_vpar->synchro.i_end + 1 - p_vpar->synchro.i_start)
 357             % MAX_DECODING_PIC) )
 358     {
 359         p_vpar->synchro.p_date_fifo[p_vpar->synchro.i_end] = mdate();
 360         p_vpar->synchro.pi_coding_types[p_vpar->synchro.i_end] = i_coding_type;
 361
 362         FIFO_INCREMENT( i_end );
 363     }
 364     else
 365     {
 366         /* FIFO full, panic() */
 367         intf_ErrMsg("vpar error: synchro fifo full, estimations will be biased");
 368     }
 369     vlc_mutex_unlock( &p_vpar->synchro.fifo_lock );
 370 }
 371
 372 /*****************************************************************************
 373  * vpar_SynchroEnd : Called when the image is totally decoded
 374  *****************************************************************************/
 375 void vpar_SynchroEnd( vpar_thread_t * p_vpar, int i_garbage )
 376 {
 377     mtime_t     tau;
 378     int         i_coding_type;
 379
 380     vlc_mutex_lock( &p_vpar->synchro.fifo_lock );
 381
 382     if (!i_garbage)
 383     {
 384         tau = mdate() - p_vpar->synchro.p_date_fifo[p_vpar->synchro.i_start];
 385         i_coding_type = p_vpar->synchro.pi_coding_types[p_vpar->synchro.i_start];
 386
 387         /* Mean with average tau, to ensure stability. */
 388         p_vpar->synchro.p_tau[i_coding_type] =
 389             (p_vpar->synchro.pi_meaningful[i_coding_type]
 390              * p_vpar->synchro.p_tau[i_coding_type] + tau)
 391             / (p_vpar->synchro.pi_meaningful[i_coding_type] + 1);
 392         if( p_vpar->synchro.pi_meaningful[i_coding_type] < MAX_PIC_AVERAGE )
 393         {
 394             p_vpar->synchro.pi_meaningful[i_coding_type]++;
 395         }
 396 #ifdef DEBUG_VPAR
 397         intf_DbgMsg("vpar synchro debug: finished decoding %s (%lld)",
 398                     i_coding_type == B_CODING_TYPE ? "B" :
 399                     (i_coding_type == P_CODING_TYPE ? "P" : "I"), tau);
 400 #endif
 401     }
 402
 403     FIFO_INCREMENT( i_start );
 404
 405     vlc_mutex_unlock( &p_vpar->synchro.fifo_lock );
 406 }
 407
 408 /*****************************************************************************
 409  * vpar_SynchroDate : When an image has been decoded, ask for its date
 410  *****************************************************************************/
 411 mtime_t vpar_SynchroDate( vpar_thread_t * p_vpar )
 412 {
 413     /* No need to lock, since PTS are only used by the video parser. */
 414     return( p_vpar->synchro.current_pts );
 415 }
 416
 417 /*****************************************************************************
 418  * vpar_SynchroNewPicture: Update stream structure and PTS
 419  *****************************************************************************/
 420 void vpar_SynchroNewPicture( vpar_thread_t * p_vpar, int i_coding_type,
 421                              int i_repeat_field )
 422 {
 423     mtime_t         period = 1000000 / (p_vpar->sequence.i_frame_rate) * 1001;
 424
 425     switch( i_coding_type )
 426     {
 427     case I_CODING_TYPE:
 428         if( p_vpar->synchro.i_eta_p
 429                 && p_vpar->synchro.i_eta_p != p_vpar->synchro.i_n_p )
 430         {
 431             intf_WarnMsg( 1, "Stream periodicity changed from P[%d] to P[%d]",
 432                           p_vpar->synchro.i_n_p, p_vpar->synchro.i_eta_p );
 433             p_vpar->synchro.i_n_p = p_vpar->synchro.i_eta_p;
 434         }
 435         p_vpar->synchro.i_eta_p = p_vpar->synchro.i_eta_b = 0;
 436 #ifdef STATS
 437         if( p_vpar->synchro.i_type == VPAR_SYNCHRO_DEFAULT )
 438         {
 439             intf_Msg( "vpar synchro stats: I(%lld) P(%lld)[%d] B(%lld)[%d] YUV(%lld) : trashed %d:%d/%d",
 440                   p_vpar->synchro.p_tau[I_CODING_TYPE],
 441                   p_vpar->synchro.p_tau[P_CODING_TYPE],
 442                   p_vpar->synchro.i_n_p,
 443                   p_vpar->synchro.p_tau[B_CODING_TYPE],
 444                   p_vpar->synchro.i_n_b,
 445                   p_vpar->p_vout->render_time,
 446                   p_vpar->synchro.i_not_chosen_pic,
 447                   p_vpar->synchro.i_trashed_pic -
 448                   p_vpar->synchro.i_not_chosen_pic,
 449                   p_vpar->synchro.i_pic );
 450             p_vpar->synchro.i_trashed_pic = p_vpar->synchro.i_not_chosen_pic
 451                 = p_vpar->synchro.i_pic = 0;
 452         }
 453 #endif
 454         break;
 455     case P_CODING_TYPE:
 456         p_vpar->synchro.i_eta_p++;
 457         if( p_vpar->synchro.i_eta_b
 458                 && p_vpar->synchro.i_eta_b != p_vpar->synchro.i_n_b )
 459         {
 460             intf_WarnMsg( 1, "Stream periodicity changed from B[%d] to B[%d]",
 461                           p_vpar->synchro.i_n_b, p_vpar->synchro.i_eta_b );
 462             p_vpar->synchro.i_n_b = p_vpar->synchro.i_eta_b;
 463         }
 464         p_vpar->synchro.i_eta_b = 0;
 465         break;
 466     case B_CODING_TYPE:
 467         p_vpar->synchro.i_eta_b++;
 468         break;
 469     }
 470
 471     p_vpar->synchro.current_pts += p_vpar->synchro.next_period;
 472
 473     /* A video frame can be displayed 1, 2 or 3 times, according to
 474      * repeat_first_field, top_field_first, progressive_sequence and
 475      * progressive_frame. */
 476     p_vpar->synchro.next_period = i_repeat_field * (period >> 1);
 477
 478 #define PTS_THRESHOLD   (period >> 2)
 479     if( i_coding_type == B_CODING_TYPE )
 480     {
 481         if( p_vpar->sequence.next_pts )
 482         {
 483             if( p_vpar->sequence.next_pts - p_vpar->synchro.current_pts
 484                     > PTS_THRESHOLD
 485                  || p_vpar->synchro.current_pts - p_vpar->sequence.next_pts
 486                     > PTS_THRESHOLD )
 487             {
 488                 intf_WarnMsg( 2,
 489                         "vpar synchro warning: pts != current_date (%lld)",
 490                         p_vpar->synchro.current_pts
 491                             - p_vpar->sequence.next_pts );
 492             }
 493             p_vpar->synchro.current_pts = p_vpar->sequence.next_pts;
 494             p_vpar->sequence.next_pts = 0;
 495         }
 496     }
 497     else
 498     {
 499         if( p_vpar->synchro.backward_pts )
 500         {
 501             if( p_vpar->sequence.next_dts &&
 502                 (p_vpar->sequence.next_dts - p_vpar->synchro.backward_pts
 503                     > PTS_THRESHOLD
 504               || p_vpar->synchro.backward_pts - p_vpar->sequence.next_dts
 505                     > PTS_THRESHOLD) )
 506             {
 507                 intf_WarnMsg( 2,
 508                         "vpar synchro warning: backward_pts != dts (%lld)",
 509                         p_vpar->synchro.backward_pts
 510                             - p_vpar->sequence.next_dts );
 511             }
 512
 513             if( p_vpar->synchro.backward_pts - p_vpar->synchro.current_pts
 514                     > PTS_THRESHOLD
 515                  || p_vpar->synchro.current_pts - p_vpar->synchro.backward_pts
 516                     > PTS_THRESHOLD )
 517             {
 518                 intf_WarnMsg( 2,
 519                    "vpar synchro warning: backward_pts != current_pts (%lld)",
 520                    p_vpar->synchro.current_pts - p_vpar->synchro.backward_pts );
 521             }
 522             p_vpar->synchro.current_pts = p_vpar->synchro.backward_pts;
 523             p_vpar->synchro.backward_pts = 0;
 524         }
 525         else if( p_vpar->sequence.next_dts )
 526         {
 527             if( p_vpar->sequence.next_dts - p_vpar->synchro.current_pts
 528                     > PTS_THRESHOLD
 529                  || p_vpar->synchro.current_pts - p_vpar->sequence.next_dts
 530                     > PTS_THRESHOLD )
 531             {
 532                 intf_WarnMsg( 2,
 533                         "vpar synchro warning: dts != current_pts (%lld)",
 534                         p_vpar->synchro.current_pts
 535                             - p_vpar->sequence.next_dts );
 536             }
 537             /* By definition of a DTS. */
 538             p_vpar->synchro.current_pts = p_vpar->sequence.next_dts;
 539             p_vpar->sequence.next_dts = 0;
 540         }
 541
 542         if( p_vpar->sequence.next_pts )
 543         {
 544             /* Store the PTS for the next time we have to date an I picture. */
 545             p_vpar->synchro.backward_pts = p_vpar->sequence.next_pts;
 546             p_vpar->sequence.next_pts = 0;
 547         }
 548     }
 549 #undef PTS_THRESHOLD
 550
 551 #ifdef STATS
 552     p_vpar->synchro.i_pic++;
 553 #endif
 554 }
 555
 556 /*****************************************************************************
 557  * SynchroType: Get the user's synchro type
 558  *****************************************************************************
 559  * This function is called at initialization.
 560  *****************************************************************************/
 561 static int SynchroType( void )
 562 {
 563     char * psz_synchro = main_GetPszVariable( VPAR_SYNCHRO_VAR, NULL );
 564
 565     if( psz_synchro == NULL )
 566     {
 567         return VPAR_SYNCHRO_DEFAULT;
 568     }
 569
 570     switch( *psz_synchro++ )
 571     {
 572       case 'i':
 573       case 'I':
 574         switch( *psz_synchro++ )
 575         {
 576           case '\0':
 577             return VPAR_SYNCHRO_I;
 578
 579           case '+':
 580             if( *psz_synchro ) return 0;
 581             return VPAR_SYNCHRO_Iplus;
 582
 583           case 'p':
 584           case 'P':
 585             switch( *psz_synchro++ )
 586             {
 587               case '\0':
 588                 return VPAR_SYNCHRO_IP;
 589
 590               case '+':
 591                 if( *psz_synchro ) return 0;
 592                 return VPAR_SYNCHRO_IPplus;
 593
 594               case 'b':
 595               case 'B':
 596                 if( *psz_synchro ) return 0;
 597                 return VPAR_SYNCHRO_IPB;
 598
 599               default:
 600                 return VPAR_SYNCHRO_DEFAULT;
 601
 602             }
 603
 604           default:
 605             return VPAR_SYNCHRO_DEFAULT;
 606         }
 607     }
 608
 609     return VPAR_SYNCHRO_DEFAULT;
 610 }
 611