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 1.190 2002/08/12 09:34:15 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 <vlc/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 #if defined( SYS_DARWIN )
  45 #include "darwin_specific.h"
  46 #endif
  47
  48 /*****************************************************************************
  49  * Local prototypes
  50  *****************************************************************************/
  51 static int      InitThread        ( vout_thread_t * );
  52 static void     RunThread         ( vout_thread_t * );
  53 static void     ErrorThread       ( vout_thread_t * );
  54 static void     EndThread         ( vout_thread_t * );
  55 static void     DestroyThread     ( vout_thread_t * );
  56
  57 static int      ReduceHeight      ( int );
  58 static int      BinaryLog         ( u32 );
  59 static void     MaskToShift       ( int *, int *, u32 );
  60 static void     InitWindowSize    ( vout_thread_t *, int *, int * );
  61
  62 /*****************************************************************************
  63  * vout_CreateThread: creates a new video output thread
  64  *****************************************************************************
  65  * This function creates a new video output thread, and returns a pointer
  66  * to its description. On error, it returns NULL.
  67  *****************************************************************************/
  68 vout_thread_t * __vout_CreateThread ( vlc_object_t *p_parent,
  69                                       int i_width, int i_height,
  70                                       vlc_fourcc_t i_chroma, int i_aspect )
  71 {
  72     vout_thread_t * p_vout;                             /* thread descriptor */
  73     int             i_index;                                /* loop variable */
  74     char          * psz_plugin;
  75
  76     /* Allocate descriptor */
  77     p_vout = vlc_object_create( p_parent, VLC_OBJECT_VOUT );
  78     if( p_vout == NULL )
  79     {
  80         msg_Err( p_parent, "out of memory" );
  81         return( NULL );
  82     }
  83
  84     /* If the parent is not a VOUT object, that means we are at the start of
  85      * the video output pipe */
  86     if( p_parent->i_object_type != VLC_OBJECT_VOUT )
  87     {
  88         /* look for the default filter configuration */
  89         p_vout->psz_filter_chain = config_GetPsz( p_parent, "filter" );
  90     }
  91     else
  92     {
  93         /* continue the parent's filter chain */
  94         char *psz_end;
  95
  96         psz_end = strchr( ((vout_thread_t *)p_parent)->psz_filter_chain, ':' );
  97         if( psz_end && *(psz_end+1) )
  98             p_vout->psz_filter_chain = strdup( psz_end+1 );
  99         else p_vout->psz_filter_chain = NULL;
 100     }
 101
 102     /* Choose the video output module */
 103     if( !p_vout->psz_filter_chain )
 104     {
 105         psz_plugin = config_GetPsz( p_parent, "vout" );
 106     }
 107     else
 108     {
 109         /* the filter chain is a string list of filters separated by double
 110          * colons */
 111         char *psz_end;
 112
 113         psz_end = strchr( p_vout->psz_filter_chain, ':' );
 114         if( psz_end )
 115             psz_plugin = strndup( p_vout->psz_filter_chain,
 116                                   psz_end - p_vout->psz_filter_chain );
 117         else psz_plugin = strdup( p_vout->psz_filter_chain );
 118     }
 119
 120     /* Initialize pictures and subpictures - translation tables and functions
 121      * will be initialized later in InitThread */
 122     for( i_index = 0; i_index < 2 * VOUT_MAX_PICTURES; i_index++)
 123     {
 124         p_vout->p_picture[i_index].i_status = FREE_PICTURE;
 125         p_vout->p_picture[i_index].i_type   = EMPTY_PICTURE;
 126     }
 127
 128     for( i_index = 0; i_index < VOUT_MAX_SUBPICTURES; i_index++)
 129     {
 130         p_vout->p_subpicture[i_index].i_status = FREE_SUBPICTURE;
 131         p_vout->p_subpicture[i_index].i_type   = EMPTY_SUBPICTURE;
 132     }
 133
 134     /* No images in the heap */
 135     p_vout->i_heap_size = 0;
 136
 137     /* Initialize the rendering heap */
 138     I_RENDERPICTURES = 0;
 139     p_vout->render.i_width    = i_width;
 140     p_vout->render.i_height   = i_height;
 141     p_vout->render.i_chroma   = i_chroma;
 142     p_vout->render.i_aspect   = i_aspect;
 143
 144     p_vout->render.i_rmask    = 0;
 145     p_vout->render.i_gmask    = 0;
 146     p_vout->render.i_bmask    = 0;
 147
 148     /* Zero the output heap */
 149     I_OUTPUTPICTURES = 0;
 150     p_vout->output.i_width    = 0;
 151     p_vout->output.i_height   = 0;
 152     p_vout->output.i_chroma   = 0;
 153     p_vout->output.i_aspect   = 0;
 154
 155     p_vout->output.i_rmask    = 0;
 156     p_vout->output.i_gmask    = 0;
 157     p_vout->output.i_bmask    = 0;
 158
 159     /* Initialize misc stuff */
 160     p_vout->i_changes    = 0;
 161     p_vout->f_gamma      = 0;
 162     p_vout->b_grayscale  = 0;
 163     p_vout->b_info       = 0;
 164     p_vout->b_interface  = 0;
 165     p_vout->b_scale      = 1;
 166     p_vout->b_fullscreen = 0;
 167     p_vout->render_time  = 10;
 168     p_vout->c_fps_samples= 0;
 169
 170     p_vout->i_mouse_x = 0;
 171     p_vout->i_mouse_y = 0;
 172     p_vout->i_mouse_button = 0;
 173
 174     /* user requested fullscreen? */
 175     if( config_GetInt( p_vout, "fullscreen" ) )
 176     {
 177         p_vout->i_changes |= VOUT_FULLSCREEN_CHANGE;
 178     }
 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 = module_Need( p_vout,
 186                            ( p_vout->psz_filter_chain ) ?
 187                            "video filter" : "video output",
 188                            psz_plugin );
 189
 190     if( psz_plugin ) free( psz_plugin );
 191     if( p_vout->p_module == NULL )
 192     {
 193         msg_Err( p_vout, "no suitable vout module" );
 194         vlc_object_destroy( p_vout );
 195         return( NULL );
 196     }
 197
 198     /* Create thread and set locks */
 199     vlc_mutex_init( p_vout, &p_vout->picture_lock );
 200     vlc_mutex_init( p_vout, &p_vout->subpicture_lock );
 201     vlc_mutex_init( p_vout, &p_vout->change_lock );
 202
 203     vlc_object_attach( p_vout, p_parent );
 204
 205     if( vlc_thread_create( p_vout, "video output", RunThread, 0 ) )
 206     {
 207         msg_Err( p_vout, "%s", strerror(ENOMEM) );
 208         module_Unneed( p_vout, p_vout->p_module );
 209         vlc_object_destroy( p_vout );
 210         return NULL;
 211     }
 212
 213     return p_vout;
 214 }
 215
 216 /*****************************************************************************
 217  * vout_DestroyThread: destroys a previously created thread
 218  *****************************************************************************
 219  * Destroy a terminated thread.
 220  * The function will request a destruction of the specified thread. If pi_error
 221  * is NULL, it will return once the thread is destroyed. Else, it will be
 222  * update using one of the THREAD_* constants.
 223  *****************************************************************************/
 224 void vout_DestroyThread( vout_thread_t *p_vout )
 225 {
 226     /* Request thread destruction */
 227     p_vout->b_die = 1;
 228     vlc_thread_join( p_vout );
 229
 230     /* Free structure */
 231     vlc_object_destroy( p_vout );
 232 }
 233
 234 /*****************************************************************************
 235  * InitThread: initialize video output thread
 236  *****************************************************************************
 237  * This function is called from RunThread and performs the second step of the
 238  * initialization. It returns 0 on success. Note that the thread's flag are not
 239  * modified inside this function.
 240  *****************************************************************************/
 241 static int InitThread( vout_thread_t *p_vout )
 242 {
 243     int i, i_pgcd;
 244
 245     vlc_mutex_lock( &p_vout->change_lock );
 246
 247 #ifdef STATS
 248     p_vout->c_loops = 0;
 249 #endif
 250
 251     /* Initialize output method, it allocates direct buffers for us */
 252     if( p_vout->pf_init( p_vout ) )
 253     {
 254         vlc_mutex_unlock( &p_vout->change_lock );
 255         return( 1 );
 256     }
 257
 258     if( !I_OUTPUTPICTURES )
 259     {
 260         msg_Err( p_vout, "plugin was unable to allocate at least "
 261                          "one direct buffer" );
 262         p_vout->pf_end( p_vout );
 263         vlc_mutex_unlock( &p_vout->change_lock );
 264         return( 1 );
 265     }
 266
 267     msg_Dbg( p_vout, "got %i direct buffer(s)", I_OUTPUTPICTURES );
 268
 269     i_pgcd = ReduceHeight( p_vout->render.i_aspect );
 270     msg_Dbg( p_vout,
 271              "picture in %ix%i, chroma 0x%.8x (%4.4s), aspect ratio %i:%i",
 272              p_vout->render.i_width, p_vout->render.i_height,
 273              p_vout->render.i_chroma, (char*)&p_vout->render.i_chroma,
 274              p_vout->render.i_aspect / i_pgcd, VOUT_ASPECT_FACTOR / i_pgcd );
 275
 276     i_pgcd = ReduceHeight( p_vout->output.i_aspect );
 277     msg_Dbg( p_vout,
 278              "picture out %ix%i, chroma 0x%.8x (%4.4s), aspect ratio %i:%i",
 279              p_vout->output.i_width, p_vout->output.i_height,
 280              p_vout->output.i_chroma, (char*)&p_vout->output.i_chroma,
 281              p_vout->output.i_aspect / i_pgcd, VOUT_ASPECT_FACTOR / i_pgcd );
 282
 283     /* Calculate shifts from system-updated masks */
 284     MaskToShift( &p_vout->output.i_lrshift, &p_vout->output.i_rrshift,
 285                  p_vout->output.i_rmask );
 286     MaskToShift( &p_vout->output.i_lgshift, &p_vout->output.i_rgshift,
 287                  p_vout->output.i_gmask );
 288     MaskToShift( &p_vout->output.i_lbshift, &p_vout->output.i_rbshift,
 289                  p_vout->output.i_bmask );
 290
 291     /* Check whether we managed to create direct buffers similar to
 292      * the render buffers, ie same size, chroma and aspect ratio */
 293     if( ( p_vout->output.i_width == p_vout->render.i_width )
 294      && ( p_vout->output.i_height == p_vout->render.i_height )
 295      && ( vout_ChromaCmp( p_vout->output.i_chroma, p_vout->render.i_chroma ) )
 296      && ( p_vout->output.i_aspect == p_vout->render.i_aspect ) )
 297     {
 298         /* Cool ! We have direct buffers, we can ask the decoder to
 299          * directly decode into them ! Map the first render buffers to
 300          * the first direct buffers, but keep the first direct buffer
 301          * for memcpy operations */
 302         p_vout->b_direct = 1;
 303
 304         msg_Dbg( p_vout, "direct render, mapping "
 305                  "render pictures 0-%i to system pictures 1-%i",
 306                  VOUT_MAX_PICTURES - 2, VOUT_MAX_PICTURES - 1 );
 307
 308         for( i = 1; i < VOUT_MAX_PICTURES; i++ )
 309         {
 310             PP_RENDERPICTURE[ I_RENDERPICTURES ] = &p_vout->p_picture[ i ];
 311             I_RENDERPICTURES++;
 312         }
 313     }
 314     else
 315     {
 316         /* Rats... Something is wrong here, we could not find an output
 317          * plugin able to directly render what we decode. See if we can
 318          * find a chroma plugin to do the conversion */
 319         p_vout->b_direct = 0;
 320
 321         /* Choose the best module */
 322         p_vout->chroma.p_module = module_Need( p_vout, "chroma", NULL );
 323
 324         if( p_vout->chroma.p_module == NULL )
 325         {
 326             msg_Err( p_vout, "no chroma module for %4.4s to %4.4s",
 327                      &p_vout->render.i_chroma, &p_vout->output.i_chroma );
 328             p_vout->pf_end( p_vout );
 329             vlc_mutex_unlock( &p_vout->change_lock );
 330             return( 1 );
 331         }
 332
 333         if( I_OUTPUTPICTURES < 2 * VOUT_MAX_PICTURES )
 334         {
 335             msg_Dbg( p_vout, "indirect render, mapping "
 336                      "render pictures %i-%i to system pictures %i-%i",
 337                      I_OUTPUTPICTURES - 1, 2 * VOUT_MAX_PICTURES - 2,
 338                      I_OUTPUTPICTURES, 2 * VOUT_MAX_PICTURES - 1 );
 339         }
 340         else
 341         {
 342             /* FIXME: if this happens, we don't have any render pictures left */
 343             msg_Dbg( p_vout, "indirect render, no system pictures needed,"
 344                      " we have %i directbuffers", I_OUTPUTPICTURES );
 345             msg_Err( p_vout, "this is a bug!" );
 346         }
 347
 348         /* Append render buffers after the direct buffers */
 349         for( i = I_OUTPUTPICTURES; i < 2 * VOUT_MAX_PICTURES; i++ )
 350         {
 351             PP_RENDERPICTURE[ I_RENDERPICTURES ] = &p_vout->p_picture[ i ];
 352             I_RENDERPICTURES++;
 353         }
 354     }
 355
 356     /* Link pictures back to their heap */
 357     for( i = 0 ; i < I_RENDERPICTURES ; i++ )
 358     {
 359         PP_RENDERPICTURE[ i ]->p_heap = &p_vout->render;
 360     }
 361
 362     for( i = 0 ; i < I_OUTPUTPICTURES ; i++ )
 363     {
 364         PP_OUTPUTPICTURE[ i ]->p_heap = &p_vout->output;
 365     }
 366
 367 /* XXX XXX mark thread ready */
 368     return( 0 );
 369 }
 370
 371 /*****************************************************************************
 372  * RunThread: video output thread
 373  *****************************************************************************
 374  * Video output thread. This function does only returns when the thread is
 375  * terminated. It handles the pictures arriving in the video heap and the
 376  * display device events.
 377  *****************************************************************************/
 378 static void RunThread( vout_thread_t *p_vout)
 379 {
 380     int             i_index;                                /* index in heap */
 381     int             i_idle_loops = 0;  /* loops without displaying a picture */
 382     mtime_t         current_date;                            /* current date */
 383     mtime_t         display_date;                            /* display date */
 384
 385     picture_t *     p_picture;                            /* picture pointer */
 386     picture_t *     p_last_picture = NULL;                   /* last picture */
 387     picture_t *     p_directbuffer;              /* direct buffer to display */
 388
 389     subpicture_t *  p_subpic;                          /* subpicture pointer */
 390
 391     /*
 392      * Initialize thread
 393      */
 394     p_vout->b_error = InitThread( p_vout );
 395     if( p_vout->b_error )
 396     {
 397         /* Destroy thread structures allocated by Create and InitThread */
 398         DestroyThread( p_vout );
 399         return;
 400     }
 401
 402     /*
 403      * Main loop - it is not executed if an error occured during
 404      * initialization
 405      */
 406     while( (!p_vout->b_die) && (!p_vout->b_error) )
 407     {
 408         /* Initialize loop variables */
 409         display_date = 0;
 410         current_date = mdate();
 411
 412 #ifdef STATS
 413         p_vout->c_loops++;
 414         if( !(p_vout->c_loops % VOUT_STATS_NB_LOOPS) )
 415         {
 416             msg_Dbg( p_vout, "picture heap: %d/%d",
 417                      I_RENDERPICTURES, p_vout->i_heap_size );
 418         }
 419 #endif
 420
 421         /*
 422          * Find the picture to display - this operation does not need lock,
 423          * since only READY_PICTUREs are handled
 424          */
 425         p_picture = NULL;
 426
 427         for( i_index = 0; i_index < I_RENDERPICTURES; i_index++ )
 428         {
 429             if( (PP_RENDERPICTURE[i_index]->i_status == READY_PICTURE)
 430                 && ( (p_picture == NULL) ||
 431                      (PP_RENDERPICTURE[i_index]->date < display_date) ) )
 432             {
 433                 p_picture = PP_RENDERPICTURE[i_index];
 434                 display_date = p_picture->date;
 435             }
 436         }
 437
 438         if( p_picture != NULL )
 439         {
 440             /* If we met the last picture, parse again to see whether there is
 441              * a more appropriate one. */
 442             if( p_picture == p_last_picture )
 443             {
 444                 for( i_index = 0; i_index < I_RENDERPICTURES; i_index++ )
 445                 {
 446                     if( (PP_RENDERPICTURE[i_index]->i_status == READY_PICTURE)
 447                         && (PP_RENDERPICTURE[i_index] != p_last_picture)
 448                         && ((p_picture == p_last_picture) ||
 449                             (PP_RENDERPICTURE[i_index]->date < display_date)) )
 450                     {
 451                         p_picture = PP_RENDERPICTURE[i_index];
 452                         display_date = p_picture->date;
 453                     }
 454                 }
 455             }
 456
 457             /* If we found better than the last picture, destroy it */
 458             if( p_last_picture && p_picture != p_last_picture )
 459             {
 460                 vlc_mutex_lock( &p_vout->picture_lock );
 461                 if( p_last_picture->i_refcount )
 462                 {
 463                     p_last_picture->i_status = DISPLAYED_PICTURE;
 464                 }
 465                 else
 466                 {
 467                     p_last_picture->i_status = DESTROYED_PICTURE;
 468                     p_vout->i_heap_size--;
 469                 }
 470                 vlc_mutex_unlock( &p_vout->picture_lock );
 471                 p_last_picture = NULL;
 472             }
 473
 474             /* Compute FPS rate */
 475             p_vout->p_fps_sample[ p_vout->c_fps_samples++ % VOUT_FPS_SAMPLES ]
 476                 = display_date;
 477
 478             if( !p_picture->b_force &&
 479                 p_picture != p_last_picture &&
 480                 display_date < current_date + p_vout->render_time )
 481             {
 482                 /* Picture is late: it will be destroyed and the thread
 483                  * will directly choose the next picture */
 484                 vlc_mutex_lock( &p_vout->picture_lock );
 485                 if( p_picture->i_refcount )
 486                 {
 487                     /* Pretend we displayed the picture, but don't destroy
 488                      * it since the decoder might still need it. */
 489                     p_picture->i_status = DISPLAYED_PICTURE;
 490                 }
 491                 else
 492                 {
 493                     /* Destroy the picture without displaying it */
 494                     p_picture->i_status = DESTROYED_PICTURE;
 495                     p_vout->i_heap_size--;
 496                 }
 497                 msg_Warn( p_vout, "late picture skipped (%lld)",
 498                                   current_date - display_date );
 499                 vlc_mutex_unlock( &p_vout->picture_lock );
 500
 501                 continue;
 502             }
 503 #if 0
 504             /* Removed because it causes problems for some people --Meuuh */
 505             if( display_date > current_date + VOUT_BOGUS_DELAY )
 506             {
 507                 /* Picture is waaay too early: it will be destroyed */
 508                 vlc_mutex_lock( &p_vout->picture_lock );
 509                 if( p_picture->i_refcount )
 510                 {
 511                     /* Pretend we displayed the picture, but don't destroy
 512                      * it since the decoder might still need it. */
 513                     p_picture->i_status = DISPLAYED_PICTURE;
 514                 }
 515                 else
 516                 {
 517                     /* Destroy the picture without displaying it */
 518                     p_picture->i_status = DESTROYED_PICTURE;
 519                     p_vout->i_heap_size--;
 520                 }
 521                 intf_WarnMsg( 1, "vout warning: early picture skipped (%lld)",
 522                               display_date - current_date );
 523                 vlc_mutex_unlock( &p_vout->picture_lock );
 524
 525                 continue;
 526             }
 527 #endif
 528             if( display_date > current_date + VOUT_DISPLAY_DELAY )
 529             {
 530                 /* A picture is ready to be rendered, but its rendering date
 531                  * is far from the current one so the thread will perform an
 532                  * empty loop as if no picture were found. The picture state
 533                  * is unchanged */
 534                 p_picture    = NULL;
 535                 display_date = 0;
 536             }
 537             else if( p_picture == p_last_picture )
 538             {
 539                 /* We are asked to repeat the previous picture, but we first
 540                  * wait for a couple of idle loops */
 541                 if( i_idle_loops < 4 )
 542                 {
 543                     p_picture    = NULL;
 544                     display_date = 0;
 545                 }
 546                 else
 547                 {
 548                     /*intf_WarnMsg( 6, "vout info: duplicating picture" );*/
 549                 }
 550             }
 551         }
 552
 553         if( p_picture == NULL )
 554         {
 555             i_idle_loops++;
 556         }
 557
 558         /*
 559          * Check for subpictures to display
 560          */
 561         p_subpic = vout_SortSubPictures( p_vout, display_date );
 562
 563         /*
 564          * Perform rendering
 565          */
 566         p_directbuffer = vout_RenderPicture( p_vout, p_picture, p_subpic );
 567
 568         /*
 569          * Call the plugin-specific rendering method if there is one
 570          */
 571         if( p_picture != NULL && p_vout->pf_render )
 572         {
 573             /* Render the direct buffer returned by vout_RenderPicture */
 574             p_vout->pf_render( p_vout, p_directbuffer );
 575         }
 576
 577         /*
 578          * Sleep, wake up
 579          */
 580         if( display_date != 0 )
 581         {
 582             /* Store render time using Bresenham algorithm */
 583             p_vout->render_time += mdate() - current_date;
 584             p_vout->render_time >>= 1;
 585         }
 586
 587         /* Give back change lock */
 588         vlc_mutex_unlock( &p_vout->change_lock );
 589
 590         /* Sleep a while or until a given date */
 591         if( display_date != 0 )
 592         {
 593             mwait( display_date - VOUT_MWAIT_TOLERANCE );
 594         }
 595         else
 596         {
 597             msleep( VOUT_IDLE_SLEEP );
 598         }
 599
 600         /* On awakening, take back lock and send immediately picture
 601          * to display. */
 602         vlc_mutex_lock( &p_vout->change_lock );
 603
 604         /*
 605          * Display the previously rendered picture
 606          */
 607         if( p_picture != NULL )
 608         {
 609             /* Display the direct buffer returned by vout_RenderPicture */
 610             if( p_vout->pf_display )
 611             {
 612                 p_vout->pf_display( p_vout, p_directbuffer );
 613             }
 614
 615             /* Reinitialize idle loop count */
 616             i_idle_loops = 0;
 617
 618             /* Tell the vout this was the last picture and that it does not
 619              * need to be forced anymore. */
 620             p_last_picture = p_picture;
 621             p_last_picture->b_force = 0;
 622         }
 623
 624         /*
 625          * Check events and manage thread
 626          */
 627         if( p_vout->pf_manage && p_vout->pf_manage( p_vout ) )
 628         {
 629             /* A fatal error occured, and the thread must terminate
 630              * immediately, without displaying anything - setting b_error to 1
 631              * causes the immediate end of the main while() loop. */
 632             p_vout->b_error = 1;
 633         }
 634
 635         if( p_vout->i_changes & VOUT_SIZE_CHANGE )
 636         {
 637             /* this must only happen when the vout plugin is incapable of
 638              * rescaling the picture itself. In this case we need to destroy
 639              * the current picture buffers and recreate new ones with the right
 640              * dimensions */
 641             int i;
 642
 643             p_vout->i_changes &= ~VOUT_SIZE_CHANGE;
 644
 645             p_vout->pf_end( p_vout );
 646             for( i = 0; i < I_OUTPUTPICTURES; i++ )
 647                  p_vout->p_picture[ i ].i_status = FREE_PICTURE;
 648
 649             I_OUTPUTPICTURES = 0;
 650             if( p_vout->pf_init( p_vout ) )
 651             {
 652                 msg_Err( p_vout, "cannot resize display" );
 653                 /* FIXME: pf_end will be called again in EndThread() */
 654                 p_vout->b_error = 1;
 655             }
 656
 657             /* Need to reinitialise the chroma plugin */
 658             p_vout->chroma.p_module->pf_deactivate( VLC_OBJECT(p_vout) );
 659             p_vout->chroma.p_module->pf_activate( VLC_OBJECT(p_vout) );
 660         }
 661
 662     }
 663
 664     /*
 665      * Error loop - wait until the thread destruction is requested
 666      */
 667     if( p_vout->b_error )
 668     {
 669         ErrorThread( p_vout );
 670     }
 671
 672     /* End of thread */
 673     EndThread( p_vout );
 674
 675     /* Destroy thread structures allocated by CreateThread */
 676     DestroyThread( p_vout );
 677 }
 678
 679 /*****************************************************************************
 680  * ErrorThread: RunThread() error loop
 681  *****************************************************************************
 682  * This function is called when an error occured during thread main's loop. The
 683  * thread can still receive feed, but must be ready to terminate as soon as
 684  * possible.
 685  *****************************************************************************/
 686 static void ErrorThread( vout_thread_t *p_vout )
 687 {
 688     /* Wait until a `die' order */
 689     while( !p_vout->b_die )
 690     {
 691         /* Sleep a while */
 692         msleep( VOUT_IDLE_SLEEP );
 693     }
 694 }
 695
 696 /*****************************************************************************
 697  * EndThread: thread destruction
 698  *****************************************************************************
 699  * This function is called when the thread ends after a sucessful
 700  * initialization. It frees all ressources allocated by InitThread.
 701  *****************************************************************************/
 702 static void EndThread( vout_thread_t *p_vout )
 703 {
 704     int     i_index;                                        /* index in heap */
 705
 706 #ifdef STATS
 707     {
 708         struct tms cpu_usage;
 709         times( &cpu_usage );
 710
 711         msg_Dbg( p_vout, "cpu usage (user: %d, system: %d)",
 712                  cpu_usage.tms_utime, cpu_usage.tms_stime );
 713     }
 714 #endif
 715
 716     if( !p_vout->b_direct )
 717     {
 718         module_Unneed( p_vout, p_vout->chroma.p_module );
 719     }
 720
 721     /* Destroy all remaining pictures */
 722     for( i_index = 0; i_index < 2 * VOUT_MAX_PICTURES; i_index++ )
 723     {
 724         if ( p_vout->p_picture[i_index].i_type == MEMORY_PICTURE )
 725         {
 726             free( p_vout->p_picture[i_index].p_data_orig );
 727         }
 728     }
 729
 730     /* Destroy all remaining subpictures */
 731     for( i_index = 0; i_index < VOUT_MAX_SUBPICTURES; i_index++ )
 732     {
 733         if( p_vout->p_subpicture[i_index].i_status != FREE_SUBPICTURE )
 734         {
 735             free( p_vout->p_subpicture[i_index].p_sys );
 736         }
 737     }
 738
 739     /* Destroy translation tables */
 740     p_vout->pf_end( p_vout );
 741
 742     /* Release the change lock */
 743     vlc_mutex_unlock( &p_vout->change_lock );
 744 }
 745
 746 /*****************************************************************************
 747  * DestroyThread: thread destruction
 748  *****************************************************************************
 749  * This function is called when the thread ends. It frees all ressources
 750  * allocated by CreateThread. Status is available at this stage.
 751  *****************************************************************************/
 752 static void DestroyThread( vout_thread_t *p_vout )
 753 {
 754     /* Destroy the locks */
 755     vlc_mutex_destroy( &p_vout->picture_lock );
 756     vlc_mutex_destroy( &p_vout->subpicture_lock );
 757     vlc_mutex_destroy( &p_vout->change_lock );
 758
 759     /* Release the module */
 760     module_Unneed( p_vout, p_vout->p_module );
 761 }
 762
 763 /* following functions are local */
 764
 765 static int ReduceHeight( int i_ratio )
 766 {
 767     int i_dummy = VOUT_ASPECT_FACTOR;
 768     int i_pgcd  = 1;
 769
 770     if( !i_ratio )
 771     {
 772         return i_pgcd;
 773     }
 774
 775     /* VOUT_ASPECT_FACTOR is (2^7 * 3^3 * 5^3), we just check for 2, 3 and 5 */
 776     while( !(i_ratio & 1) && !(i_dummy & 1) )
 777     {
 778         i_ratio >>= 1;
 779         i_dummy >>= 1;
 780         i_pgcd  <<= 1;
 781     }
 782
 783     while( !(i_ratio % 3) && !(i_dummy % 3) )
 784     {
 785         i_ratio /= 3;
 786         i_dummy /= 3;
 787         i_pgcd  *= 3;
 788     }
 789
 790     while( !(i_ratio % 5) && !(i_dummy % 5) )
 791     {
 792         i_ratio /= 5;
 793         i_dummy /= 5;
 794         i_pgcd  *= 5;
 795     }
 796
 797     return i_pgcd;
 798 }
 799
 800 /*****************************************************************************
 801  * BinaryLog: computes the base 2 log of a binary value
 802  *****************************************************************************
 803  * This functions is used by MaskToShift, to get a bit index from a binary
 804  * value.
 805  *****************************************************************************/
 806 static int BinaryLog(u32 i)
 807 {
 808     int i_log = 0;
 809
 810     if( i == 0 ) return -31337;
 811
 812     if( i & 0xffff0000 ) i_log += 16;
 813     if( i & 0xff00ff00 ) i_log += 8;
 814     if( i & 0xf0f0f0f0 ) i_log += 4;
 815     if( i & 0xcccccccc ) i_log += 2;
 816     if( i & 0xaaaaaaaa ) i_log += 1;
 817
 818     return( i_log );
 819 }
 820
 821 /*****************************************************************************
 822  * MaskToShift: transform a color mask into right and left shifts
 823  *****************************************************************************
 824  * This function is used for obtaining color shifts from masks.
 825  *****************************************************************************/
 826 static void MaskToShift( int *pi_left, int *pi_right, u32 i_mask )
 827 {
 828     u32 i_low, i_high;                 /* lower hand higher bits of the mask */
 829
 830     if( !i_mask )
 831     {
 832         *pi_left = *pi_right = 0;
 833         return;
 834     }
 835
 836     /* Get bits */
 837     i_low =  i_mask & (- i_mask);                   /* lower bit of the mask */
 838     i_high = i_mask + i_low;                       /* higher bit of the mask */
 839
 840     /* Transform bits into an index */
 841     i_low =  BinaryLog (i_low);
 842     i_high = BinaryLog (i_high);
 843
 844     /* Update pointers and return */
 845     *pi_left =   i_low;
 846     *pi_right = (8 - i_high + i_low);
 847 }
 848
 849 /*****************************************************************************
 850  * InitWindowSize: find the initial dimensions the video window should have.
 851  *****************************************************************************
 852  * This function will check the "width", "height" and "zoom" config options and
 853  * will calculate the size that the video window should have.
 854  *****************************************************************************/
 855 static void InitWindowSize( vout_thread_t *p_vout, int *pi_width,
 856                             int *pi_height )
 857 {
 858     int i_width, i_height;
 859     double f_zoom;
 860
 861     i_width = config_GetInt( p_vout, "width" );
 862     i_height = config_GetInt( p_vout, "height" );
 863     f_zoom = config_GetFloat( p_vout, "zoom" );
 864
 865     if( (i_width >= 0) && (i_height >= 0))
 866     {
 867         *pi_width = i_width * f_zoom;
 868         *pi_height = i_height * f_zoom;
 869         return;
 870     }
 871     else if( i_width >= 0 )
 872     {
 873         *pi_width = i_width * f_zoom;
 874         *pi_height = i_width * f_zoom * VOUT_ASPECT_FACTOR /
 875                         p_vout->render.i_aspect;
 876         return;
 877     }
 878     else if( i_height >= 0 )
 879     {
 880         *pi_height = i_height * f_zoom;
 881         *pi_width = i_height * f_zoom * p_vout->render.i_aspect /
 882                        VOUT_ASPECT_FACTOR;
 883         return;
 884     }
 885
 886     if( p_vout->render.i_height * p_vout->render.i_aspect
 887         >= p_vout->render.i_width * VOUT_ASPECT_FACTOR )
 888     {
 889         *pi_width = p_vout->render.i_height * f_zoom
 890           * p_vout->render.i_aspect / VOUT_ASPECT_FACTOR;
 891         *pi_height = p_vout->render.i_height * f_zoom;
 892     }
 893     else
 894     {
 895         *pi_width = p_vout->render.i_width * f_zoom;
 896         *pi_height = p_vout->render.i_width * f_zoom
 897           * VOUT_ASPECT_FACTOR / p_vout->render.i_aspect;
 898     }
 899 }