git.sesse.net Git - vlc/blob - src/video_output/video_output.c

   1 /*****************************************************************************
   2  * video_output.c : video output thread
   3  * This module describes the programming interface for video output threads.
   4  * It includes functions allowing to open a new thread, send pictures to a
   5  * thread, and destroy a previously oppened video output thread.
   6  *****************************************************************************
   7  * Copyright (C) 2000-2001 VideoLAN
   8  * $Id: video_output.c,v 1.149 2001/12/30 07:09:56 sam Exp $
   9  *
  10  * Authors: Vincent Seguin <seguin@via.ecp.fr>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30 #include <errno.h>                                                 /* ENOMEM */
  31 #include <stdlib.h>                                                /* free() */
  32 #include <stdio.h>                                              /* sprintf() */
  33 #include <string.h>                                            /* strerror() */
  34
  35 #include <videolan/vlc.h>
  36
  37 #ifdef HAVE_SYS_TIMES_H
  38 #   include <sys/times.h>
  39 #endif
  40
  41 #include "video.h"
  42 #include "video_output.h"
  43
  44 /*****************************************************************************
  45  * Local prototypes
  46  *****************************************************************************/
  47 static int      InitThread        ( vout_thread_t *p_vout );
  48 static void     RunThread         ( vout_thread_t *p_vout );
  49 static void     ErrorThread       ( vout_thread_t *p_vout );
  50 static void     EndThread         ( vout_thread_t *p_vout );
  51 static void     DestroyThread     ( vout_thread_t *p_vout, int i_status );
  52 static int      ReduceHeight      ( int );
  53
  54 /*****************************************************************************
  55  * vout_InitBank: initialize the video output bank.
  56  *****************************************************************************/
  57 void vout_InitBank ( void )
  58 {
  59     p_vout_bank->i_count = 0;
  60
  61     vlc_mutex_init( &p_vout_bank->lock );
  62 }
  63
  64 /*****************************************************************************
  65  * vout_EndBank: empty the video output bank.
  66  *****************************************************************************
  67  * This function ends all unused video outputs and empties the bank in
  68  * case of success.
  69  *****************************************************************************/
  70 void vout_EndBank ( void )
  71 {
  72     /* Ask all remaining video outputs to die */
  73     while( p_vout_bank->i_count )
  74     {
  75         vout_DestroyThread(
  76                 p_vout_bank->pp_vout[ --p_vout_bank->i_count ], NULL );
  77     }
  78
  79     vlc_mutex_destroy( &p_vout_bank->lock );
  80 }
  81
  82 /*****************************************************************************
  83  * vout_CreateThread: creates a new video output thread
  84  *****************************************************************************
  85  * This function creates a new video output thread, and returns a pointer
  86  * to its description. On error, it returns NULL.
  87  * If pi_status is NULL, then the function will block until the thread is ready.
  88  * If not, it will be updated using one of the THREAD_* constants.
  89  *****************************************************************************/
  90 vout_thread_t * vout_CreateThread   ( int *pi_status,
  91                                       int i_width, int i_height,
  92                                       int i_chroma, int i_aspect )
  93 {
  94     vout_thread_t * p_vout;                             /* thread descriptor */
  95     int             i_status;                               /* thread status */
  96     int             i_index;                                /* loop variable */
  97
  98     /* Allocate descriptor */
  99     p_vout = (vout_thread_t *) malloc( sizeof(vout_thread_t) );
 100     if( p_vout == NULL )
 101     {
 102         intf_ErrMsg( "vout error: vout thread creation returned %s",
 103                      strerror(ENOMEM) );
 104         return( NULL );
 105     }
 106
 107     /* Choose the best module */
 108     p_vout->p_module =
 109         module_Need( MODULE_CAPABILITY_VOUT,
 110                      main_GetPszVariable( VOUT_FILTER_VAR,
 111                          main_GetPszVariable( VOUT_METHOD_VAR, NULL ) ),
 112                      NULL );
 113
 114     if( p_vout->p_module == NULL )
 115     {
 116         intf_ErrMsg( "vout error: no suitable vout module" );
 117         free( p_vout );
 118         return( NULL );
 119     }
 120
 121 #define f p_vout->p_module->p_functions->vout.functions.vout
 122     p_vout->pf_create     = f.pf_create;
 123     p_vout->pf_init       = f.pf_init;
 124     p_vout->pf_end        = f.pf_end;
 125     p_vout->pf_destroy    = f.pf_destroy;
 126     p_vout->pf_manage     = f.pf_manage;
 127     p_vout->pf_display    = f.pf_display;
 128     p_vout->pf_setpalette = f.pf_setpalette;
 129 #undef f
 130
 131     /* Initialize thread properties - thread id and locks will be initialized
 132      * later */
 133     p_vout->b_die               = 0;
 134     p_vout->b_error             = 0;
 135     p_vout->b_active            = 0;
 136     p_vout->pi_status           = (pi_status != NULL) ? pi_status : &i_status;
 137     *p_vout->pi_status          = THREAD_CREATE;
 138
 139     /* Initialize pictures and subpictures - translation tables and functions
 140      * will be initialized later in InitThread */
 141     for( i_index = 0; i_index < VOUT_MAX_PICTURES; i_index++)
 142     {
 143         p_vout->p_picture[i_index].i_status = FREE_PICTURE;
 144         p_vout->p_picture[i_index].i_type   = EMPTY_PICTURE;
 145     }
 146
 147     for( i_index = 0; i_index < VOUT_MAX_SUBPICTURES; i_index++)
 148     {
 149         p_vout->p_subpicture[i_index].i_status = FREE_SUBPICTURE;
 150         p_vout->p_subpicture[i_index].i_type   = EMPTY_SUBPICTURE;
 151     }
 152
 153     /* Initialize the rendering heap */
 154     p_vout->i_heap_size = 0;
 155
 156     I_RENDERPICTURES = 0;
 157     p_vout->render.i_width    = i_width;
 158     p_vout->render.i_height   = i_height;
 159     p_vout->render.i_chroma   = i_chroma;
 160     p_vout->render.i_aspect   = i_aspect;
 161
 162     /* Initialize misc stuff */
 163     p_vout->i_changes    = 0;
 164     p_vout->f_gamma      = 0;
 165     p_vout->b_grayscale  = 0;
 166     p_vout->b_info       = 0;
 167     p_vout->b_interface  = 0;
 168     p_vout->b_scale      = 1;
 169     p_vout->b_fullscreen = main_GetIntVariable( VOUT_FULLSCREEN_VAR,
 170                                                 VOUT_FULLSCREEN_DEFAULT );
 171     p_vout->render_time  = 10;
 172
 173     /* Create thread and set locks */
 174     vlc_mutex_init( &p_vout->picture_lock );
 175     vlc_mutex_init( &p_vout->subpicture_lock );
 176     vlc_mutex_init( &p_vout->change_lock );
 177
 178     if( vlc_thread_create( &p_vout->thread_id, "video output",
 179                            (void *) RunThread, (void *) p_vout) )
 180     {
 181         intf_ErrMsg("vout error: %s", strerror(ENOMEM));
 182         p_vout->pf_destroy( p_vout );
 183         module_Unneed( p_vout->p_module );
 184         free( p_vout );
 185         return( NULL );
 186     }
 187
 188     /* If status is NULL, wait until the thread is created */
 189     if( pi_status == NULL )
 190     {
 191         do
 192         {
 193             msleep( THREAD_SLEEP );
 194         }while( (i_status != THREAD_READY) && (i_status != THREAD_ERROR)
 195                 && (i_status != THREAD_FATAL) );
 196         if( i_status != THREAD_READY )
 197         {
 198             return( NULL );
 199         }
 200     }
 201
 202     return( p_vout );
 203 }
 204
 205 /*****************************************************************************
 206  * vout_DestroyThread: destroys a previously created thread
 207  *****************************************************************************
 208  * Destroy a terminated thread.
 209  * The function will request a destruction of the specified thread. If pi_error
 210  * is NULL, it will return once the thread is destroyed. Else, it will be
 211  * update using one of the THREAD_* constants.
 212  *****************************************************************************/
 213 void vout_DestroyThread( vout_thread_t *p_vout, int *pi_status )
 214 {
 215     int     i_status;                                       /* thread status */
 216
 217     /* Set status */
 218     p_vout->pi_status = (pi_status != NULL) ? pi_status : &i_status;
 219     *p_vout->pi_status = THREAD_DESTROY;
 220
 221     /* Request thread destruction */
 222     p_vout->b_die = 1;
 223
 224     /* If status is NULL, wait until thread has been destroyed */
 225     if( pi_status == NULL )
 226     {
 227         do
 228         {
 229             msleep( THREAD_SLEEP );
 230         } while( (i_status != THREAD_OVER) && (i_status != THREAD_ERROR)
 231                  && (i_status != THREAD_FATAL) );
 232     }
 233 }
 234
 235 /*****************************************************************************
 236  * InitThread: initialize video output thread
 237  *****************************************************************************
 238  * This function is called from RunThread and performs the second step of the
 239  * initialization. It returns 0 on success. Note that the thread's flag are not
 240  * modified inside this function.
 241  *****************************************************************************/
 242 static int InitThread( vout_thread_t *p_vout )
 243 {
 244     int i, i_pgcd;
 245     probedata_t data;
 246
 247     /* Update status */
 248     *p_vout->pi_status = THREAD_START;
 249
 250     vlc_mutex_lock( &p_vout->change_lock );
 251
 252 #ifdef STATS
 253     p_vout->c_loops = 0;
 254 #endif
 255
 256     /* Initialize output method, it issues its own error messages */
 257     if( p_vout->pf_init( p_vout ) )
 258     {
 259         vlc_mutex_unlock( &p_vout->change_lock );
 260         return( 1 );
 261     }
 262
 263     if( !I_OUTPUTPICTURES )
 264     {
 265         intf_ErrMsg( "vout error: plugin was unable to allocate at least "
 266                      "one direct buffer" );
 267         p_vout->pf_end( p_vout );
 268         vlc_mutex_unlock( &p_vout->change_lock );
 269         return( 1 );
 270     }
 271
 272     intf_WarnMsg( 1, "vout info: got %i direct buffer(s)", I_OUTPUTPICTURES );
 273
 274     i_pgcd = ReduceHeight( p_vout->render.i_aspect );
 275     intf_WarnMsg( 1, "vout info: picture in %ix%i, chroma %i, "
 276                      "aspect ratio %i:%i",
 277                   p_vout->render.i_width, p_vout->render.i_height,
 278                   p_vout->render.i_chroma, p_vout->render.i_aspect / i_pgcd,
 279                   VOUT_ASPECT_FACTOR / i_pgcd );
 280
 281     i_pgcd = ReduceHeight( p_vout->output.i_aspect );
 282     intf_WarnMsg( 1, "vout info: picture out %ix%i, chroma %i, "
 283                      "aspect ratio %i:%i",
 284                   p_vout->output.i_width, p_vout->output.i_height,
 285                   p_vout->output.i_chroma, p_vout->output.i_aspect / i_pgcd,
 286                   VOUT_ASPECT_FACTOR / i_pgcd );
 287
 288     /* Check whether we managed to create direct buffers similar to
 289      * the render buffers, ie same size, chroma and aspect ratio */
 290     if( ( p_vout->output.i_width == p_vout->render.i_width )
 291      && ( p_vout->output.i_height == p_vout->render.i_height )
 292      && ( p_vout->output.i_chroma == p_vout->render.i_chroma )
 293      && ( p_vout->output.i_aspect == p_vout->render.i_aspect ) )
 294     {
 295         /* Cool ! We have direct buffers, we can ask the decoder to
 296          * directly decode into them ! Map the first render buffers to
 297          * the first direct buffers, but keep the first direct buffer
 298          * for memcpy operations */
 299         p_vout->b_direct = 1;
 300
 301         intf_WarnMsg( 2, "vout info: mapping "
 302                          "render pictures 0-%i to system pictures 1-%i",
 303                          VOUT_MAX_PICTURES - 2, VOUT_MAX_PICTURES - 1 );
 304
 305         for( i = 1; i < VOUT_MAX_PICTURES; i++ )
 306         {
 307             PP_RENDERPICTURE[ I_RENDERPICTURES ] = &p_vout->p_picture[ i ];
 308             I_RENDERPICTURES++;
 309         }
 310
 311     }
 312     else
 313     {
 314         /* Rats... Something is wrong here, we could not find an output
 315          * plugin able to directly render what we decode. See if we can
 316          * find a chroma plugin to do the conversion */
 317         p_vout->b_direct = 0;
 318
 319         /* Choose the best module */
 320         data.chroma.p_render = &p_vout->render;
 321         data.chroma.p_output = &p_vout->output;
 322         p_vout->chroma.p_module
 323             = module_Need( MODULE_CAPABILITY_CHROMA, NULL, &data );
 324
 325         if( p_vout->chroma.p_module == NULL )
 326         {
 327             intf_ErrMsg( "vout error: no suitable chroma module" );
 328             p_vout->pf_end( p_vout );
 329             vlc_mutex_unlock( &p_vout->change_lock );
 330             return( 1 );
 331         }
 332
 333 #define f p_vout->chroma.p_module->p_functions->chroma.functions.chroma
 334         p_vout->chroma.pf_init       = f.pf_init;
 335         p_vout->chroma.pf_end        = f.pf_end;
 336 #undef f
 337
 338         if( p_vout->chroma.pf_init( p_vout ) )
 339         {
 340             intf_ErrMsg( "vout error: could not initialize chroma module" );
 341             module_Unneed( p_vout->chroma.p_module );
 342             p_vout->pf_end( p_vout );
 343             vlc_mutex_unlock( &p_vout->change_lock );
 344             return( 1 );
 345         }
 346
 347         intf_WarnMsg( 2, "vout info: mapping "
 348                          "render pictures %i-%i to system pictures %i-%i",
 349                          I_OUTPUTPICTURES - 1, VOUT_MAX_PICTURES - 2,
 350                          I_OUTPUTPICTURES, VOUT_MAX_PICTURES - 1 );
 351
 352         /* Append render buffers after the direct buffers */
 353         for( i = I_OUTPUTPICTURES; i < VOUT_MAX_PICTURES; i++ )
 354         {
 355             PP_RENDERPICTURE[ I_RENDERPICTURES ] = &p_vout->p_picture[ i ];
 356             I_RENDERPICTURES++;
 357         }
 358     }
 359
 360     /* Mark thread as running and return */
 361     p_vout->b_active = 1;
 362     *p_vout->pi_status = THREAD_READY;
 363
 364     intf_DbgMsg("thread ready");
 365     return( 0 );
 366 }
 367
 368 /*****************************************************************************
 369  * RunThread: video output thread
 370  *****************************************************************************
 371  * Video output thread. This function does only returns when the thread is
 372  * terminated. It handles the pictures arriving in the video heap and the
 373  * display device events.
 374  *****************************************************************************/
 375 static void RunThread( vout_thread_t *p_vout)
 376 {
 377     int             i_index;                                /* index in heap */
 378     mtime_t         current_date;                            /* current date */
 379     mtime_t         display_date;                            /* display date */
 380
 381     picture_t *     p_picture;                            /* picture pointer */
 382     picture_t *     p_directbuffer;              /* direct buffer to display */
 383
 384     subpicture_t *  p_subpic;                          /* subpicture pointer */
 385
 386     /* Create and initialize system-dependant method - this function issues its
 387      * own error messages */
 388     if( p_vout->pf_create( p_vout ) )
 389     {
 390         DestroyThread( p_vout, THREAD_ERROR );
 391         return;
 392     }
 393
 394     /*
 395      * Initialize thread
 396      */
 397     p_vout->b_error = InitThread( p_vout );
 398     if( p_vout->b_error )
 399     {
 400         /* Destroy thread structures allocated by Create and InitThread */
 401         p_vout->pf_destroy( p_vout );
 402
 403         DestroyThread( p_vout, THREAD_ERROR );
 404         return;
 405     }
 406
 407     /*
 408      * Main loop - it is not executed if an error occured during
 409      * initialization
 410      */
 411     while( (!p_vout->b_die) && (!p_vout->b_error) )
 412     {
 413         /* Initialize loop variables */
 414         display_date = 0;
 415         current_date = mdate();
 416
 417 #ifdef STATS
 418         p_vout->c_loops++;
 419         if( !(p_vout->c_loops % VOUT_STATS_NB_LOOPS) )
 420         {
 421             intf_Msg( "vout stats: picture heap: %d/%d",
 422                       I_RENDERPICTURES, p_vout->i_heap_size );
 423         }
 424 #endif
 425
 426         /*
 427          * Find the picture to display - this operation does not need lock,
 428          * since only READY_PICTUREs are handled
 429          */
 430         p_picture = NULL;
 431
 432         for( i_index = 0;
 433              i_index < I_RENDERPICTURES;
 434              i_index++ )
 435         {
 436             if( (PP_RENDERPICTURE[i_index]->i_status == READY_PICTURE)
 437                 && ( (p_picture == NULL) ||
 438                      (PP_RENDERPICTURE[i_index]->date < display_date) ) )
 439             {
 440                 p_picture = PP_RENDERPICTURE[i_index];
 441                 display_date = p_picture->date;
 442             }
 443         }
 444
 445         if( p_picture != NULL )
 446         {
 447             /* Compute FPS rate */
 448             p_vout->p_fps_sample[ p_vout->c_fps_samples++ % VOUT_FPS_SAMPLES ]
 449                 = display_date;
 450
 451             if( display_date < current_date + p_vout->render_time )
 452             {
 453                 /* Picture is late: it will be destroyed and the thread
 454                  * will directly choose the next picture */
 455                 vlc_mutex_lock( &p_vout->picture_lock );
 456                 if( p_picture->i_refcount )
 457                 {
 458                     /* Pretend we displayed the picture, but don't destroy
 459                      * it since the decoder might still need it. */
 460                     p_picture->i_status = DISPLAYED_PICTURE;
 461                 }
 462                 else
 463                 {
 464                     /* Destroy the picture without displaying it */
 465                     p_picture->i_status = DESTROYED_PICTURE;
 466                     p_vout->i_heap_size--;
 467                 }
 468                 intf_WarnMsg( 1, "vout warning: late picture skipped (%p)",
 469                               p_picture );
 470                 vlc_mutex_unlock( &p_vout->picture_lock );
 471
 472                 continue;
 473             }
 474             else if( display_date > current_date + VOUT_DISPLAY_DELAY )
 475             {
 476                 /* A picture is ready to be rendered, but its rendering date
 477                  * is far from the current one so the thread will perform an
 478                  * empty loop as if no picture were found. The picture state
 479                  * is unchanged */
 480                 p_picture    = NULL;
 481                 display_date = 0;
 482             }
 483         }
 484
 485         /*
 486          * Check for subpictures to display
 487          */
 488         p_subpic = vout_SortSubPictures( p_vout, display_date );
 489
 490         /*
 491          * Perform rendering
 492          */
 493         p_directbuffer = vout_RenderPicture( p_vout, p_picture, p_subpic );
 494
 495         /*
 496          * Sleep, wake up
 497          */
 498         if( display_date != 0 )
 499         {
 500             /* Store render time using Bresenham algorithm */
 501             p_vout->render_time += mdate() - current_date;
 502             p_vout->render_time >>= 1;
 503         }
 504
 505         /* Give back change lock */
 506         vlc_mutex_unlock( &p_vout->change_lock );
 507
 508         /* Sleep a while or until a given date */
 509         if( display_date != 0 )
 510         {
 511             mwait( display_date - VOUT_MWAIT_TOLERANCE );
 512         }
 513         else
 514         {
 515             msleep( VOUT_IDLE_SLEEP );
 516         }
 517
 518         /* On awakening, take back lock and send immediately picture
 519          * to display. */
 520         vlc_mutex_lock( &p_vout->change_lock );
 521
 522 #ifdef TRACE_VOUT
 523         intf_DbgMsg( "picture %p, subpicture %p", p_picture, p_subpic );
 524 #endif
 525
 526         /*
 527          * Display the previously rendered picture
 528          */
 529         if( p_picture != NULL )
 530         {
 531             /* Display the direct buffer returned by vout_RenderPicture */
 532             p_vout->pf_display( p_vout, p_directbuffer );
 533
 534             /* Remove picture from heap */
 535             vlc_mutex_lock( &p_vout->picture_lock );
 536             if( p_picture->i_refcount )
 537             {
 538                 p_picture->i_status = DISPLAYED_PICTURE;
 539             }
 540             else
 541             {
 542                 p_picture->i_status = DESTROYED_PICTURE;
 543                 p_vout->i_heap_size--;
 544             }
 545             vlc_mutex_unlock( &p_vout->picture_lock );
 546         }
 547
 548         /*
 549          * Check events and manage thread
 550          */
 551         if( p_vout->pf_manage( p_vout ) )
 552         {
 553             /* A fatal error occured, and the thread must terminate immediately,
 554              * without displaying anything - setting b_error to 1 causes the
 555              * immediate end of the main while() loop. */
 556             p_vout->b_error = 1;
 557         }
 558     }
 559
 560     /*
 561      * Error loop - wait until the thread destruction is requested
 562      */
 563     if( p_vout->b_error )
 564     {
 565         ErrorThread( p_vout );
 566     }
 567
 568     /* End of thread */
 569     EndThread( p_vout );
 570
 571     /* Destroy method-dependant resources */
 572     p_vout->pf_destroy( p_vout );
 573
 574     /* Destroy thread structures allocated by CreateThread */
 575     DestroyThread( p_vout, THREAD_OVER );
 576     intf_DbgMsg( "thread end" );
 577 }
 578
 579 /*****************************************************************************
 580  * ErrorThread: RunThread() error loop
 581  *****************************************************************************
 582  * This function is called when an error occured during thread main's loop. The
 583  * thread can still receive feed, but must be ready to terminate as soon as
 584  * possible.
 585  *****************************************************************************/
 586 static void ErrorThread( vout_thread_t *p_vout )
 587 {
 588     /* Wait until a `die' order */
 589     while( !p_vout->b_die )
 590     {
 591         /* Sleep a while */
 592         msleep( VOUT_IDLE_SLEEP );
 593     }
 594 }
 595
 596 /*****************************************************************************
 597  * EndThread: thread destruction
 598  *****************************************************************************
 599  * This function is called when the thread ends after a sucessful
 600  * initialization. It frees all ressources allocated by InitThread.
 601  *****************************************************************************/
 602 static void EndThread( vout_thread_t *p_vout )
 603 {
 604     int     i_index;                                        /* index in heap */
 605
 606     /* Store status */
 607     *p_vout->pi_status = THREAD_END;
 608
 609 #ifdef STATS
 610     {
 611         struct tms cpu_usage;
 612         times( &cpu_usage );
 613
 614         intf_Msg( "vout stats: cpu usage (user: %d, system: %d)",
 615                   cpu_usage.tms_utime, cpu_usage.tms_stime );
 616     }
 617 #endif
 618
 619     if( !p_vout->b_direct )
 620     {
 621         p_vout->chroma.pf_end( p_vout );
 622         module_Unneed( p_vout->chroma.p_module );
 623     }
 624
 625     /* Destroy all remaining pictures */
 626     for( i_index = 0; i_index < VOUT_MAX_PICTURES; i_index++ )
 627     {
 628         if ( p_vout->p_picture[i_index].i_type == MEMORY_PICTURE )
 629         {
 630             free( p_vout->p_picture[i_index].planes[0].p_data );
 631         }
 632     }
 633
 634     /* Destroy all remaining subpictures */
 635     for( i_index = 0; i_index < VOUT_MAX_SUBPICTURES; i_index++ )
 636     {
 637         if( p_vout->p_subpicture[i_index].i_status != FREE_SUBPICTURE )
 638         {
 639             free( p_vout->p_subpicture[i_index].p_data );
 640         }
 641     }
 642
 643     /* Destroy translation tables */
 644     p_vout->pf_end( p_vout );
 645
 646     /* Release the change lock */
 647     vlc_mutex_unlock( &p_vout->change_lock );
 648 }
 649
 650 /*****************************************************************************
 651  * DestroyThread: thread destruction
 652  *****************************************************************************
 653  * This function is called when the thread ends. It frees all ressources
 654  * allocated by CreateThread. Status is available at this stage.
 655  *****************************************************************************/
 656 static void DestroyThread( vout_thread_t *p_vout, int i_status )
 657 {
 658     int *pi_status;                                         /* status adress */
 659
 660     /* Store status adress */
 661     pi_status = p_vout->pi_status;
 662
 663     /* Destroy the locks */
 664     vlc_mutex_destroy( &p_vout->picture_lock );
 665     vlc_mutex_destroy( &p_vout->subpicture_lock );
 666     vlc_mutex_destroy( &p_vout->change_lock );
 667
 668     /* Release the module */
 669     module_Unneed( p_vout->p_module );
 670
 671     /* Free structure */
 672     free( p_vout );
 673     *pi_status = i_status;
 674 }
 675
 676 static int ReduceHeight( int i_ratio )
 677 {
 678     int i_dummy = VOUT_ASPECT_FACTOR;
 679     int i_pgcd  = 1;
 680
 681     /* VOUT_ASPECT_FACTOR is (2^7 * 3^3 * 5^3), we just check for 2, 3 and 5 */
 682     while( !(i_ratio & 1) && !(i_dummy & 1) )
 683     {
 684         i_ratio >>= 1;
 685         i_dummy >>= 1;
 686         i_pgcd  <<= 1;
 687     }
 688
 689     while( !(i_ratio % 3) && !(i_ratio % 3) )
 690     {
 691         i_ratio /= 3;
 692         i_dummy /= 3;
 693         i_pgcd  *= 3;
 694     }
 695
 696     while( !(i_ratio % 5) && !(i_ratio % 5) )
 697     {
 698         i_ratio /= 5;
 699         i_dummy /= 5;
 700         i_pgcd  *= 5;
 701     }
 702
 703     return i_pgcd;
 704 }
 705