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 1.178 2002/05/23 22:21:14 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
  53 static int      ReduceHeight      ( int );
  54 static int      BinaryLog         ( u32 );
  55 static void     MaskToShift       ( int *, int *, u32 );
  56 static void     InitWindowSize    ( vout_thread_t *, int *, int * );
  57
  58 /*****************************************************************************
  59  * vout_InitBank: initialize the video output bank.
  60  *****************************************************************************/
  61 void vout_InitBank ( void )
  62 {
  63     p_vout_bank->i_count = 0;
  64
  65     vlc_mutex_init( &p_vout_bank->lock );
  66 }
  67
  68 /*****************************************************************************
  69  * vout_EndBank: empty the video output bank.
  70  *****************************************************************************
  71  * This function ends all unused video outputs and empties the bank in
  72  * case of success.
  73  *****************************************************************************/
  74 void vout_EndBank ( void )
  75 {
  76     /* Ask all remaining video outputs to die */
  77     while( p_vout_bank->i_count )
  78     {
  79         vout_DestroyThread(
  80                 p_vout_bank->pp_vout[ --p_vout_bank->i_count ], NULL );
  81     }
  82
  83     vlc_mutex_destroy( &p_vout_bank->lock );
  84 }
  85
  86 /*****************************************************************************
  87  * vout_CreateThread: creates a new video output thread
  88  *****************************************************************************
  89  * This function creates a new video output thread, and returns a pointer
  90  * to its description. On error, it returns NULL.
  91  * If pi_status is NULL, then the function will block until the thread is ready.
  92  * If not, it will be updated using one of the THREAD_* constants.
  93  *****************************************************************************/
  94 vout_thread_t * vout_CreateThread   ( int *pi_status,
  95                                       int i_width, int i_height,
  96                                       u32 i_chroma, int i_aspect )
  97 {
  98     vout_thread_t * p_vout;                             /* thread descriptor */
  99     int             i_status;                               /* thread status */
 100     int             i_index;                                /* loop variable */
 101     char          * psz_plugin;
 102
 103     /* Allocate descriptor */
 104     p_vout = (vout_thread_t *) malloc( sizeof(vout_thread_t) );
 105     if( p_vout == NULL )
 106     {
 107         intf_ErrMsg( "vout error: vout thread creation returned %s",
 108                      strerror(ENOMEM) );
 109         return( NULL );
 110     }
 111
 112     /* Choose the best module */
 113     if( !(psz_plugin = config_GetPszVariable( "filter" )) )
 114     {
 115         psz_plugin = config_GetPszVariable( "vout" );
 116     }
 117
 118     /* Initialize thread properties - thread id and locks will be initialized
 119      * later */
 120     p_vout->b_die               = 0;
 121     p_vout->b_error             = 0;
 122     p_vout->b_active            = 0;
 123     p_vout->pi_status           = (pi_status != NULL) ? pi_status : &i_status;
 124     *p_vout->pi_status          = THREAD_CREATE;
 125
 126     /* Initialize pictures and subpictures - translation tables and functions
 127      * will be initialized later in InitThread */
 128     for( i_index = 0; i_index < 2 * VOUT_MAX_PICTURES; i_index++)
 129     {
 130         p_vout->p_picture[i_index].i_status = FREE_PICTURE;
 131         p_vout->p_picture[i_index].i_type   = EMPTY_PICTURE;
 132     }
 133
 134     for( i_index = 0; i_index < VOUT_MAX_SUBPICTURES; i_index++)
 135     {
 136         p_vout->p_subpicture[i_index].i_status = FREE_SUBPICTURE;
 137         p_vout->p_subpicture[i_index].i_type   = EMPTY_SUBPICTURE;
 138     }
 139
 140     /* No images in the heap */
 141     p_vout->i_heap_size = 0;
 142
 143     /* Initialize the rendering heap */
 144     I_RENDERPICTURES = 0;
 145     p_vout->render.i_width    = i_width;
 146     p_vout->render.i_height   = i_height;
 147     p_vout->render.i_chroma   = i_chroma;
 148     p_vout->render.i_aspect   = i_aspect;
 149
 150     p_vout->render.i_rmask    = 0;
 151     p_vout->render.i_gmask    = 0;
 152     p_vout->render.i_bmask    = 0;
 153
 154     /* Zero the output heap */
 155     I_OUTPUTPICTURES = 0;
 156     p_vout->output.i_width    = 0;
 157     p_vout->output.i_height   = 0;
 158     p_vout->output.i_chroma   = 0;
 159     p_vout->output.i_aspect   = 0;
 160
 161     p_vout->output.i_rmask    = 0;
 162     p_vout->output.i_gmask    = 0;
 163     p_vout->output.i_bmask    = 0;
 164
 165     /* Initialize misc stuff */
 166     p_vout->i_changes    = 0;
 167     p_vout->f_gamma      = 0;
 168     p_vout->b_grayscale  = 0;
 169     p_vout->b_info       = 0;
 170     p_vout->b_interface  = 0;
 171     p_vout->b_scale      = 1;
 172     p_vout->b_fullscreen = 0;
 173     p_vout->render_time  = 10;
 174     p_vout->c_fps_samples= 0;
 175
 176     /* user requested fullscreen? */
 177     if( config_GetIntVariable( "fullscreen" ) )
 178         p_vout->i_changes |= VOUT_FULLSCREEN_CHANGE;
 179
 180     /* Initialize the dimensions of the video window */
 181     InitWindowSize( p_vout, &p_vout->i_window_width,
 182                     &p_vout->i_window_height );
 183
 184
 185     p_vout->p_module
 186         = module_Need( MODULE_CAPABILITY_VOUT, psz_plugin, (void *)p_vout );
 187
 188     if( psz_plugin ) free( psz_plugin );
 189     if( p_vout->p_module == NULL )
 190     {
 191         intf_ErrMsg( "vout error: no suitable vout module" );
 192         free( p_vout );
 193         return( NULL );
 194     }
 195
 196 #define f p_vout->p_module->p_functions->vout.functions.vout
 197     p_vout->pf_create     = f.pf_create;
 198     p_vout->pf_init       = f.pf_init;
 199     p_vout->pf_end        = f.pf_end;
 200     p_vout->pf_destroy    = f.pf_destroy;
 201     p_vout->pf_manage     = f.pf_manage;
 202     p_vout->pf_render     = f.pf_render;
 203     p_vout->pf_display    = f.pf_display;
 204 #undef f
 205
 206     /* Create thread and set locks */
 207     vlc_mutex_init( &p_vout->picture_lock );
 208     vlc_mutex_init( &p_vout->subpicture_lock );
 209     vlc_mutex_init( &p_vout->change_lock );
 210
 211     if( vlc_thread_create( &p_vout->thread_id, "video output",
 212                            (void *) RunThread, (void *) p_vout) )
 213     {
 214         intf_ErrMsg("vout error: %s", strerror(ENOMEM));
 215         p_vout->pf_destroy( p_vout );
 216         module_Unneed( p_vout->p_module );
 217         free( p_vout );
 218         return( NULL );
 219     }
 220
 221     /* If status is NULL, wait until the thread is created */
 222     if( pi_status == NULL )
 223     {
 224         do
 225         {
 226             msleep( THREAD_SLEEP );
 227         }while( (i_status != THREAD_READY) && (i_status != THREAD_ERROR)
 228                 && (i_status != THREAD_FATAL) );
 229         if( i_status != THREAD_READY )
 230         {
 231             return( NULL );
 232         }
 233     }
 234
 235     return( p_vout );
 236 }
 237
 238 /*****************************************************************************
 239  * vout_DestroyThread: destroys a previously created thread
 240  *****************************************************************************
 241  * Destroy a terminated thread.
 242  * The function will request a destruction of the specified thread. If pi_error
 243  * is NULL, it will return once the thread is destroyed. Else, it will be
 244  * update using one of the THREAD_* constants.
 245  *****************************************************************************/
 246 void vout_DestroyThread( vout_thread_t *p_vout, int *pi_status )
 247 {
 248     int     i_status;                                       /* thread status */
 249
 250     /* Set status */
 251     p_vout->pi_status = (pi_status != NULL) ? pi_status : &i_status;
 252     *p_vout->pi_status = THREAD_DESTROY;
 253
 254     /* Request thread destruction */
 255     p_vout->b_die = 1;
 256     /* only if pi_status is NULL */
 257     vlc_thread_join( p_vout->thread_id );
 258
 259     /* Free structure */
 260     free( p_vout );
 261 }
 262
 263 /*****************************************************************************
 264  * vout_ChromaCmp: compare two chroma values
 265  *****************************************************************************
 266  * This function returns 1 if the two fourcc values given as argument are
 267  * the same format (eg. UYVY / UYNV) or almost the same format (eg. I420/YV12)
 268  *****************************************************************************/
 269 int vout_ChromaCmp( u32 i_chroma, u32 i_amorhc )
 270 {
 271     /* If they are the same, they are the same ! */
 272     if( i_chroma == i_amorhc )
 273     {
 274         return 1;
 275     }
 276
 277     /* Check for equivalence classes */
 278     switch( i_chroma )
 279     {
 280         case FOURCC_I420:
 281         case FOURCC_IYUV:
 282         case FOURCC_YV12:
 283             switch( i_amorhc )
 284             {
 285                 case FOURCC_I420:
 286                 case FOURCC_IYUV:
 287                 case FOURCC_YV12:
 288                     return 1;
 289
 290                 default:
 291                     return 0;
 292             }
 293
 294         case FOURCC_UYVY:
 295         case FOURCC_UYNV:
 296         case FOURCC_Y422:
 297             switch( i_amorhc )
 298             {
 299                 case FOURCC_UYVY:
 300                 case FOURCC_UYNV:
 301                 case FOURCC_Y422:
 302                     return 1;
 303
 304                 default:
 305                     return 0;
 306             }
 307
 308         case FOURCC_YUY2:
 309         case FOURCC_YUNV:
 310             switch( i_amorhc )
 311             {
 312                 case FOURCC_YUY2:
 313                 case FOURCC_YUNV:
 314                     return 1;
 315
 316                 default:
 317                     return 0;
 318             }
 319
 320         default:
 321             return 0;
 322     }
 323 }
 324
 325 /*****************************************************************************
 326  * InitThread: initialize video output thread
 327  *****************************************************************************
 328  * This function is called from RunThread and performs the second step of the
 329  * initialization. It returns 0 on success. Note that the thread's flag are not
 330  * modified inside this function.
 331  *****************************************************************************/
 332 static int InitThread( vout_thread_t *p_vout )
 333 {
 334     int i, i_pgcd;
 335
 336     /* Update status */
 337     *p_vout->pi_status = THREAD_START;
 338
 339     vlc_mutex_lock( &p_vout->change_lock );
 340
 341 #ifdef STATS
 342     p_vout->c_loops = 0;
 343 #endif
 344
 345     /* Initialize output method, it allocates direct buffers for us */
 346     if( p_vout->pf_init( p_vout ) )
 347     {
 348         vlc_mutex_unlock( &p_vout->change_lock );
 349         return( 1 );
 350     }
 351
 352     if( !I_OUTPUTPICTURES )
 353     {
 354         intf_ErrMsg( "vout error: plugin was unable to allocate at least "
 355                      "one direct buffer" );
 356         p_vout->pf_end( p_vout );
 357         vlc_mutex_unlock( &p_vout->change_lock );
 358         return( 1 );
 359     }
 360
 361     intf_WarnMsg( 1, "vout info: got %i direct buffer(s)", I_OUTPUTPICTURES );
 362
 363     i_pgcd = ReduceHeight( p_vout->render.i_aspect );
 364     intf_WarnMsg( 1, "vout info: picture in %ix%i, chroma 0x%.8x (%4.4s), "
 365                      "aspect ratio %i:%i",
 366                   p_vout->render.i_width, p_vout->render.i_height,
 367                   p_vout->render.i_chroma, (char*)&p_vout->render.i_chroma,
 368                   p_vout->render.i_aspect / i_pgcd,
 369                   VOUT_ASPECT_FACTOR / i_pgcd );
 370
 371     i_pgcd = ReduceHeight( p_vout->output.i_aspect );
 372     intf_WarnMsg( 1, "vout info: picture out %ix%i, chroma 0x%.8x (%4.4s), "
 373                      "aspect ratio %i:%i",
 374                   p_vout->output.i_width, p_vout->output.i_height,
 375                   p_vout->output.i_chroma, (char*)&p_vout->output.i_chroma,
 376                   p_vout->output.i_aspect / i_pgcd,
 377                   VOUT_ASPECT_FACTOR / i_pgcd );
 378
 379     /* Calculate shifts from system-updated masks */
 380     MaskToShift( &p_vout->output.i_lrshift, &p_vout->output.i_rrshift,
 381                  p_vout->output.i_rmask );
 382     MaskToShift( &p_vout->output.i_lgshift, &p_vout->output.i_rgshift,
 383                  p_vout->output.i_gmask );
 384     MaskToShift( &p_vout->output.i_lbshift, &p_vout->output.i_rbshift,
 385                  p_vout->output.i_bmask );
 386
 387     /* Check whether we managed to create direct buffers similar to
 388      * the render buffers, ie same size, chroma and aspect ratio */
 389     if( ( p_vout->output.i_width == p_vout->render.i_width )
 390      && ( p_vout->output.i_height == p_vout->render.i_height )
 391      && ( vout_ChromaCmp( p_vout->output.i_chroma, p_vout->render.i_chroma ) )
 392      && ( p_vout->output.i_aspect == p_vout->render.i_aspect ) )
 393     {
 394         /* Cool ! We have direct buffers, we can ask the decoder to
 395          * directly decode into them ! Map the first render buffers to
 396          * the first direct buffers, but keep the first direct buffer
 397          * for memcpy operations */
 398         p_vout->b_direct = 1;
 399
 400         intf_WarnMsg( 2, "vout info: direct render, mapping "
 401                          "render pictures 0-%i to system pictures 1-%i",
 402                          VOUT_MAX_PICTURES - 2, VOUT_MAX_PICTURES - 1 );
 403
 404         for( i = 1; i < VOUT_MAX_PICTURES; i++ )
 405         {
 406             PP_RENDERPICTURE[ I_RENDERPICTURES ] = &p_vout->p_picture[ i ];
 407             I_RENDERPICTURES++;
 408         }
 409     }
 410     else
 411     {
 412         /* Rats... Something is wrong here, we could not find an output
 413          * plugin able to directly render what we decode. See if we can
 414          * find a chroma plugin to do the conversion */
 415         p_vout->b_direct = 0;
 416
 417         /* Choose the best module */
 418         p_vout->chroma.p_module
 419             = module_Need( MODULE_CAPABILITY_CHROMA, NULL, (void *)p_vout );
 420
 421         if( p_vout->chroma.p_module == NULL )
 422         {
 423             intf_ErrMsg( "vout error: no chroma module for %4.4s to %4.4s",
 424                          &p_vout->render.i_chroma, &p_vout->output.i_chroma );
 425             p_vout->pf_end( p_vout );
 426             vlc_mutex_unlock( &p_vout->change_lock );
 427             return( 1 );
 428         }
 429
 430 #define f p_vout->chroma.p_module->p_functions->chroma.functions.chroma
 431         p_vout->chroma.pf_init       = f.pf_init;
 432         p_vout->chroma.pf_end        = f.pf_end;
 433 #undef f
 434
 435         if( I_OUTPUTPICTURES < 2 * VOUT_MAX_PICTURES )
 436         {
 437             intf_WarnMsg( 2, "vout info: indirect render, mapping "
 438                              "render pictures %i-%i to system pictures %i-%i",
 439                              I_OUTPUTPICTURES - 1, 2 * VOUT_MAX_PICTURES - 2,
 440                              I_OUTPUTPICTURES, 2 * VOUT_MAX_PICTURES - 1 );
 441         }
 442         else
 443         {
 444             /* FIXME: if this happens, we don't have any render picture left */
 445             intf_WarnMsg( 2, "vout info: indirect render, no system "
 446                              "pictures needed, we have %i directbuffers",
 447                              I_OUTPUTPICTURES );
 448             intf_ErrMsg( "vout: this is a bug!\n");
 449         }
 450
 451         /* Append render buffers after the direct buffers */
 452         for( i = I_OUTPUTPICTURES; i < 2 * VOUT_MAX_PICTURES; i++ )
 453         {
 454             PP_RENDERPICTURE[ I_RENDERPICTURES ] = &p_vout->p_picture[ i ];
 455             I_RENDERPICTURES++;
 456         }
 457     }
 458
 459     /* Link pictures back to their heap */
 460     for( i = 0 ; i < I_RENDERPICTURES ; i++ )
 461     {
 462         PP_RENDERPICTURE[ i ]->p_heap = &p_vout->render;
 463     }
 464
 465     for( i = 0 ; i < I_OUTPUTPICTURES ; i++ )
 466     {
 467         PP_OUTPUTPICTURE[ i ]->p_heap = &p_vout->output;
 468     }
 469
 470     /* Mark thread as running and return */
 471     p_vout->b_active = 1;
 472     *p_vout->pi_status = THREAD_READY;
 473
 474     return( 0 );
 475 }
 476
 477 /*****************************************************************************
 478  * RunThread: video output thread
 479  *****************************************************************************
 480  * Video output thread. This function does only returns when the thread is
 481  * terminated. It handles the pictures arriving in the video heap and the
 482  * display device events.
 483  *****************************************************************************/
 484 static void RunThread( vout_thread_t *p_vout)
 485 {
 486     int             i_index;                                /* index in heap */
 487     mtime_t         current_date;                            /* current date */
 488     mtime_t         display_date;                            /* display date */
 489
 490     picture_t *     p_picture;                            /* picture pointer */
 491     picture_t *     p_directbuffer;              /* direct buffer to display */
 492
 493     subpicture_t *  p_subpic;                          /* subpicture pointer */
 494
 495     /*
 496      * Initialize thread
 497      */
 498     p_vout->b_error = InitThread( p_vout );
 499     if( p_vout->b_error )
 500     {
 501         /* Destroy thread structures allocated by Create and InitThread */
 502         p_vout->pf_destroy( p_vout );
 503
 504         DestroyThread( p_vout, THREAD_ERROR );
 505         return;
 506     }
 507
 508     /*
 509      * Main loop - it is not executed if an error occured during
 510      * initialization
 511      */
 512     while( (!p_vout->b_die) && (!p_vout->b_error) )
 513     {
 514         /* Initialize loop variables */
 515         display_date = 0;
 516         current_date = mdate();
 517
 518 #ifdef STATS
 519         p_vout->c_loops++;
 520         if( !(p_vout->c_loops % VOUT_STATS_NB_LOOPS) )
 521         {
 522             intf_Msg( "vout stats: picture heap: %d/%d",
 523                       I_RENDERPICTURES, p_vout->i_heap_size );
 524         }
 525 #endif
 526
 527         /*
 528          * Find the picture to display - this operation does not need lock,
 529          * since only READY_PICTUREs are handled
 530          */
 531         p_picture = NULL;
 532
 533         for( i_index = 0;
 534              i_index < I_RENDERPICTURES;
 535              i_index++ )
 536         {
 537             if( (PP_RENDERPICTURE[i_index]->i_status == READY_PICTURE)
 538                 && ( (p_picture == NULL) ||
 539                      (PP_RENDERPICTURE[i_index]->date < display_date) ) )
 540             {
 541                 p_picture = PP_RENDERPICTURE[i_index];
 542                 display_date = p_picture->date;
 543             }
 544         }
 545
 546         if( p_picture != NULL )
 547         {
 548             /* Compute FPS rate */
 549             p_vout->p_fps_sample[ p_vout->c_fps_samples++ % VOUT_FPS_SAMPLES ]
 550                 = display_date;
 551
 552             if( display_date < current_date + p_vout->render_time )
 553             {
 554                 /* Picture is late: it will be destroyed and the thread
 555                  * will directly choose the next picture */
 556                 vlc_mutex_lock( &p_vout->picture_lock );
 557                 if( p_picture->i_refcount )
 558                 {
 559                     /* Pretend we displayed the picture, but don't destroy
 560                      * it since the decoder might still need it. */
 561                     p_picture->i_status = DISPLAYED_PICTURE;
 562                 }
 563                 else
 564                 {
 565                     /* Destroy the picture without displaying it */
 566                     p_picture->i_status = DESTROYED_PICTURE;
 567                     p_vout->i_heap_size--;
 568                 }
 569                 intf_WarnMsg( 1, "vout warning: late picture skipped (%lld)",
 570                               current_date - display_date );
 571                 vlc_mutex_unlock( &p_vout->picture_lock );
 572
 573                 continue;
 574             }
 575 #if 0
 576             /* Removed because it causes problems for some people --Meuuh */
 577             else if( display_date > current_date + VOUT_BOGUS_DELAY )
 578             {
 579                 /* Picture is waaay too early: it will be destroyed */
 580                 vlc_mutex_lock( &p_vout->picture_lock );
 581                 if( p_picture->i_refcount )
 582                 {
 583                     /* Pretend we displayed the picture, but don't destroy
 584                      * it since the decoder might still need it. */
 585                     p_picture->i_status = DISPLAYED_PICTURE;
 586                 }
 587                 else
 588                 {
 589                     /* Destroy the picture without displaying it */
 590                     p_picture->i_status = DESTROYED_PICTURE;
 591                     p_vout->i_heap_size--;
 592                 }
 593                 intf_WarnMsg( 1, "vout warning: early picture skipped (%lld)",
 594                               display_date - current_date );
 595                 vlc_mutex_unlock( &p_vout->picture_lock );
 596
 597                 continue;
 598             }
 599 #endif
 600             else if( display_date > current_date + VOUT_DISPLAY_DELAY )
 601             {
 602                 /* A picture is ready to be rendered, but its rendering date
 603                  * is far from the current one so the thread will perform an
 604                  * empty loop as if no picture were found. The picture state
 605                  * is unchanged */
 606                 p_picture    = NULL;
 607                 display_date = 0;
 608             }
 609         }
 610
 611         /*
 612          * Check for subpictures to display
 613          */
 614         p_subpic = vout_SortSubPictures( p_vout, display_date );
 615
 616         /*
 617          * Perform rendering
 618          */
 619         p_directbuffer = vout_RenderPicture( p_vout, p_picture, p_subpic );
 620
 621         /*
 622          * Call the plugin-specific rendering method
 623          */
 624         if( p_picture != NULL )
 625         {
 626             /* Render the direct buffer returned by vout_RenderPicture */
 627             p_vout->pf_render( p_vout, p_directbuffer );
 628         }
 629
 630         /*
 631          * Sleep, wake up
 632          */
 633         if( display_date != 0 )
 634         {
 635             /* Store render time using Bresenham algorithm */
 636             p_vout->render_time += mdate() - current_date;
 637             p_vout->render_time >>= 1;
 638         }
 639
 640         /* Give back change lock */
 641         vlc_mutex_unlock( &p_vout->change_lock );
 642
 643         /* Sleep a while or until a given date */
 644         if( display_date != 0 )
 645         {
 646             mwait( display_date - VOUT_MWAIT_TOLERANCE );
 647         }
 648         else
 649         {
 650             msleep( VOUT_IDLE_SLEEP );
 651         }
 652
 653         /* On awakening, take back lock and send immediately picture
 654          * to display. */
 655         vlc_mutex_lock( &p_vout->change_lock );
 656
 657         /*
 658          * Display the previously rendered picture
 659          */
 660         if( p_picture != NULL )
 661         {
 662             /* Display the direct buffer returned by vout_RenderPicture */
 663             p_vout->pf_display( p_vout, p_directbuffer );
 664
 665             /* Remove picture from heap */
 666             vlc_mutex_lock( &p_vout->picture_lock );
 667             if( p_picture->i_refcount )
 668             {
 669                 p_picture->i_status = DISPLAYED_PICTURE;
 670             }
 671             else
 672             {
 673                 p_picture->i_status = DESTROYED_PICTURE;
 674                 p_vout->i_heap_size--;
 675             }
 676             vlc_mutex_unlock( &p_vout->picture_lock );
 677         }
 678
 679         /*
 680          * Check events and manage thread
 681          */
 682         if( p_vout->pf_manage( p_vout ) )
 683         {
 684             /* A fatal error occured, and the thread must terminate
 685              * immediately, without displaying anything - setting b_error to 1
 686              * causes the immediate end of the main while() loop. */
 687             p_vout->b_error = 1;
 688         }
 689
 690         if( p_vout->i_changes & VOUT_SIZE_CHANGE )
 691         {
 692             /* this must only happen when the vout plugin is incapable of
 693              * rescaling the picture itself. In this case we need to destroy
 694              * the current picture buffers and recreate new ones with the right
 695              * dimensions */
 696             int i;
 697
 698             p_vout->i_changes &= ~VOUT_SIZE_CHANGE;
 699
 700             p_vout->pf_end( p_vout );
 701             for( i = 0; i < I_OUTPUTPICTURES; i++ )
 702                  p_vout->p_picture[ i ].i_status = FREE_PICTURE;
 703
 704             I_OUTPUTPICTURES = 0;
 705             if( p_vout->pf_init( p_vout ) )
 706             {
 707                 intf_ErrMsg( "vout error: cannot resize display" );
 708                 /* FixMe: p_vout->pf_end will be called again in EndThread() */
 709                 p_vout->b_error = 1;
 710             }
 711
 712             /* Need to reinitialise the chroma plugin */
 713             p_vout->chroma.pf_end( p_vout );
 714             p_vout->chroma.pf_init( p_vout );
 715         }
 716
 717     }
 718
 719     /*
 720      * Error loop - wait until the thread destruction is requested
 721      */
 722     if( p_vout->b_error )
 723     {
 724         ErrorThread( p_vout );
 725     }
 726
 727     /* End of thread */
 728     EndThread( p_vout );
 729
 730     /* Destroy method-dependant resources */
 731     p_vout->pf_destroy( p_vout );
 732
 733     /* Destroy thread structures allocated by CreateThread */
 734     DestroyThread( p_vout, THREAD_OVER );
 735 }
 736
 737 /*****************************************************************************
 738  * ErrorThread: RunThread() error loop
 739  *****************************************************************************
 740  * This function is called when an error occured during thread main's loop. The
 741  * thread can still receive feed, but must be ready to terminate as soon as
 742  * possible.
 743  *****************************************************************************/
 744 static void ErrorThread( vout_thread_t *p_vout )
 745 {
 746     /* Wait until a `die' order */
 747     while( !p_vout->b_die )
 748     {
 749         /* Sleep a while */
 750         msleep( VOUT_IDLE_SLEEP );
 751     }
 752 }
 753
 754 /*****************************************************************************
 755  * EndThread: thread destruction
 756  *****************************************************************************
 757  * This function is called when the thread ends after a sucessful
 758  * initialization. It frees all ressources allocated by InitThread.
 759  *****************************************************************************/
 760 static void EndThread( vout_thread_t *p_vout )
 761 {
 762     int     i_index;                                        /* index in heap */
 763
 764     /* Store status */
 765     *p_vout->pi_status = THREAD_END;
 766
 767 #ifdef STATS
 768     {
 769         struct tms cpu_usage;
 770         times( &cpu_usage );
 771
 772         intf_Msg( "vout stats: cpu usage (user: %d, system: %d)",
 773                   cpu_usage.tms_utime, cpu_usage.tms_stime );
 774     }
 775 #endif
 776
 777     if( !p_vout->b_direct )
 778     {
 779         p_vout->chroma.pf_end( p_vout );
 780         module_Unneed( p_vout->chroma.p_module );
 781     }
 782
 783     /* Destroy all remaining pictures */
 784     for( i_index = 0; i_index < 2 * VOUT_MAX_PICTURES; i_index++ )
 785     {
 786         if ( p_vout->p_picture[i_index].i_type == MEMORY_PICTURE )
 787         {
 788             free( p_vout->p_picture[i_index].p_data_orig );
 789         }
 790     }
 791
 792     /* Destroy all remaining subpictures */
 793     for( i_index = 0; i_index < VOUT_MAX_SUBPICTURES; i_index++ )
 794     {
 795         if( p_vout->p_subpicture[i_index].i_status != FREE_SUBPICTURE )
 796         {
 797             free( p_vout->p_subpicture[i_index].p_sys );
 798         }
 799     }
 800
 801     /* Destroy translation tables */
 802     p_vout->pf_end( p_vout );
 803
 804     /* Release the change lock */
 805     vlc_mutex_unlock( &p_vout->change_lock );
 806 }
 807
 808 /*****************************************************************************
 809  * DestroyThread: thread destruction
 810  *****************************************************************************
 811  * This function is called when the thread ends. It frees all ressources
 812  * allocated by CreateThread. Status is available at this stage.
 813  *****************************************************************************/
 814 static void DestroyThread( vout_thread_t *p_vout, int i_status )
 815 {
 816     int *pi_status;                                         /* status adress */
 817
 818     /* Store status adress */
 819     pi_status = p_vout->pi_status;
 820
 821     /* Destroy the locks */
 822     vlc_mutex_destroy( &p_vout->picture_lock );
 823     vlc_mutex_destroy( &p_vout->subpicture_lock );
 824     vlc_mutex_destroy( &p_vout->change_lock );
 825
 826     /* Release the module */
 827     module_Unneed( p_vout->p_module );
 828
 829     *pi_status = i_status;
 830 }
 831
 832 /* following functions are local */
 833
 834 static int ReduceHeight( int i_ratio )
 835 {
 836     int i_dummy = VOUT_ASPECT_FACTOR;
 837     int i_pgcd  = 1;
 838
 839     if( !i_ratio )
 840     {
 841         return i_pgcd;
 842     }
 843
 844     /* VOUT_ASPECT_FACTOR is (2^7 * 3^3 * 5^3), we just check for 2, 3 and 5 */
 845     while( !(i_ratio & 1) && !(i_dummy & 1) )
 846     {
 847         i_ratio >>= 1;
 848         i_dummy >>= 1;
 849         i_pgcd  <<= 1;
 850     }
 851
 852     while( !(i_ratio % 3) && !(i_dummy % 3) )
 853     {
 854         i_ratio /= 3;
 855         i_dummy /= 3;
 856         i_pgcd  *= 3;
 857     }
 858
 859     while( !(i_ratio % 5) && !(i_dummy % 5) )
 860     {
 861         i_ratio /= 5;
 862         i_dummy /= 5;
 863         i_pgcd  *= 5;
 864     }
 865
 866     return i_pgcd;
 867 }
 868
 869 /*****************************************************************************
 870  * BinaryLog: computes the base 2 log of a binary value
 871  *****************************************************************************
 872  * This functions is used by MaskToShift, to get a bit index from a binary
 873  * value.
 874  *****************************************************************************/
 875 static int BinaryLog(u32 i)
 876 {
 877     int i_log = 0;
 878
 879     if(i & 0xffff0000) i_log += 16;
 880     if(i & 0xff00ff00) i_log += 8;
 881     if(i & 0xf0f0f0f0) i_log += 4;
 882     if(i & 0xcccccccc) i_log += 2;
 883     if(i & 0xaaaaaaaa) i_log += 1;
 884
 885     if (i != ((u32)1 << i_log))
 886     {
 887         intf_ErrMsg( "vout error: binary log overflow for %i", i );
 888     }
 889
 890     return( i_log );
 891 }
 892
 893 /*****************************************************************************
 894  * MaskToShift: transform a color mask into right and left shifts
 895  *****************************************************************************
 896  * This function is used for obtaining color shifts from masks.
 897  *****************************************************************************/
 898 static void MaskToShift( int *pi_left, int *pi_right, u32 i_mask )
 899 {
 900     u32 i_low, i_high;                 /* lower hand higher bits of the mask */
 901
 902     if( !i_mask )
 903     {
 904         *pi_left = *pi_right = 0;
 905         return;
 906     }
 907
 908     /* Get bits */
 909     i_low =  i_mask & (- i_mask);                   /* lower bit of the mask */
 910     i_high = i_mask + i_low;                       /* higher bit of the mask */
 911
 912     /* Transform bits into an index */
 913     i_low =  BinaryLog (i_low);
 914     i_high = BinaryLog (i_high);
 915
 916     /* Update pointers and return */
 917     *pi_left =   i_low;
 918     *pi_right = (8 - i_high + i_low);
 919 }
 920
 921 /*****************************************************************************
 922  * InitWindowSize: find the initial dimensions the video window should have.
 923  *****************************************************************************
 924  * This function will check the "width", "height" and "zoom" config options and
 925  * will calculate the size that the video window should have.
 926  *****************************************************************************/
 927 static void InitWindowSize( vout_thread_t *p_vout, int *pi_width,
 928                             int *pi_height )
 929 {
 930     int i_width, i_height;
 931     double f_zoom;
 932
 933     i_width = config_GetIntVariable( "width" );
 934     i_height = config_GetIntVariable( "height" );
 935     f_zoom = config_GetFloatVariable( "zoom" );
 936
 937     if( (i_width >= 0) && (i_height >= 0))
 938     {
 939         *pi_width = i_width * f_zoom;
 940         *pi_height = i_height * f_zoom;
 941         return;
 942     }
 943     else if( i_width >= 0 )
 944     {
 945         *pi_width = i_width * f_zoom;
 946         *pi_height = i_width * f_zoom * VOUT_ASPECT_FACTOR /
 947                         p_vout->render.i_aspect;
 948         return;
 949     }
 950     else if( i_height >= 0 )
 951     {
 952         *pi_height = i_height * f_zoom;
 953         *pi_width = i_height * f_zoom * p_vout->render.i_aspect /
 954                        VOUT_ASPECT_FACTOR;
 955         return;
 956     }
 957
 958     if( p_vout->render.i_height * p_vout->render.i_aspect
 959         >= p_vout->render.i_width * VOUT_ASPECT_FACTOR )
 960     {
 961         *pi_width = p_vout->render.i_height * f_zoom
 962           * p_vout->render.i_aspect / VOUT_ASPECT_FACTOR;
 963         *pi_height = p_vout->render.i_height * f_zoom;
 964     }
 965     else
 966     {
 967         *pi_width = p_vout->render.i_width * f_zoom;
 968         *pi_height = p_vout->render.i_width * f_zoom
 969           * VOUT_ASPECT_FACTOR / p_vout->render.i_aspect;
 970     }
 971 }