git.sesse.net Git - vlc/blob - modules/video_filter/motiondetect.c

   1 /*****************************************************************************
   2  * motiondetec.c : Second version of a motion detection plugin.
   3  *****************************************************************************
   4  * Copyright (C) 2000-2008 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Antoine Cellerier <dionoea -at- videolan -dot- org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_sout.h>
  35 #include <vlc_vout.h>
  36
  37 #include "vlc_filter.h"
  38 #include "filter_picture.h"
  39
  40 /*****************************************************************************
  41  * Module descriptor
  42  *****************************************************************************/
  43 static int  Create    ( vlc_object_t * );
  44 static void Destroy   ( vlc_object_t * );
  45
  46 #define FILTER_PREFIX "motiondetect-"
  47
  48 vlc_module_begin ()
  49     set_description( N_("Motion detect video filter") )
  50     set_shortname( N_( "Motion Detect" ))
  51     set_category( CAT_VIDEO )
  52     set_subcategory( SUBCAT_VIDEO_VFILTER )
  53     set_capability( "video filter2", 0 )
  54
  55     add_shortcut( "motion" )
  56     set_callbacks( Create, Destroy )
  57 vlc_module_end ()
  58
  59
  60 /*****************************************************************************
  61  * Local prototypes
  62  *****************************************************************************/
  63 static picture_t *Filter( filter_t *, picture_t * );
  64 static picture_t *FilterPacked( filter_t *, picture_t * );
  65 static void GaussianConvolution( uint32_t *, uint32_t *, int, int, int );
  66 static int FindShapes( uint32_t *, uint32_t *, int, int, int,
  67                        int *, int *, int *, int *, int *);
  68 static void Draw( filter_t *p_filter, uint8_t *p_pix, int i_pix_pitch, int i_pix_size );
  69 #define NUM_COLORS (5000)
  70
  71 struct filter_sys_t
  72 {
  73     bool b_old;
  74     picture_t *p_old;
  75     uint32_t *p_buf;
  76     uint32_t *p_buf2;
  77
  78     /* */
  79     int i_colors;
  80     int colors[NUM_COLORS];
  81     int color_x_min[NUM_COLORS];
  82     int color_x_max[NUM_COLORS];
  83     int color_y_min[NUM_COLORS];
  84     int color_y_max[NUM_COLORS];
  85 };
  86
  87 /*****************************************************************************
  88  * Create
  89  *****************************************************************************/
  90 static int Create( vlc_object_t *p_this )
  91 {
  92     filter_t *p_filter = (filter_t *)p_this;
  93     const video_format_t *p_fmt = &p_filter->fmt_in.video;
  94     filter_sys_t *p_sys;
  95
  96     switch( p_fmt->i_chroma )
  97     {
  98         CASE_PLANAR_YUV
  99             p_filter->pf_video_filter = Filter;
 100             break;
 101
 102         CASE_PACKED_YUV_422
 103             p_filter->pf_video_filter = FilterPacked;
 104             break;
 105
 106         default:
 107             msg_Err( p_filter, "Unsupported input chroma (%4s)",
 108                      (char*)&(p_fmt->i_chroma) );
 109             return VLC_EGENERIC;
 110     }
 111
 112     /* Allocate structure */
 113     p_filter->p_sys = p_sys = malloc( sizeof( filter_sys_t ) );
 114     if( p_filter->p_sys == NULL )
 115         return VLC_ENOMEM;
 116
 117     p_sys->b_old = false;
 118     p_sys->p_old = picture_New( p_fmt->i_chroma,
 119                                 p_fmt->i_width, p_fmt->i_height, 0 );
 120     p_sys->p_buf  = calloc( p_fmt->i_width * p_fmt->i_height, sizeof(*p_sys->p_buf) );
 121     p_sys->p_buf2 = calloc( p_fmt->i_width * p_fmt->i_height, sizeof(*p_sys->p_buf) );
 122
 123     if( !p_sys->p_old || !p_sys->p_buf || !p_sys->p_buf2 )
 124     {
 125         free( p_sys->p_buf2 );
 126         free( p_sys->p_buf );
 127         if( p_sys->p_old )
 128             picture_Release( p_sys->p_old );
 129         return VLC_ENOMEM;
 130     }
 131
 132     return VLC_SUCCESS;
 133 }
 134
 135 /*****************************************************************************
 136  * Destroy
 137  *****************************************************************************/
 138 static void Destroy( vlc_object_t *p_this )
 139 {
 140     filter_t *p_filter = (filter_t *)p_this;
 141     filter_sys_t *p_sys = p_filter->p_sys;
 142
 143     free( p_sys->p_buf2 );
 144     free( p_sys->p_buf );
 145     picture_Release( p_sys->p_old );
 146     free( p_sys );
 147 }
 148
 149
 150 /*****************************************************************************
 151  * Filter YUV Planar
 152  *****************************************************************************/
 153 static picture_t *Filter( filter_t *p_filter, picture_t *p_inpic )
 154 {
 155     filter_sys_t *p_sys = p_filter->p_sys;
 156     const video_format_t *p_fmt = &p_filter->fmt_in.video;
 157
 158     picture_t *p_outpic;
 159
 160     uint8_t *p_oldpix   = p_sys->p_old->p[Y_PLANE].p_pixels;
 161     const int i_old_pitch = p_sys->p_old->p[Y_PLANE].i_pitch;
 162     uint32_t *p_buf = p_sys->p_buf;
 163     uint32_t *p_buf2= p_sys->p_buf2;
 164
 165     unsigned x, y;
 166
 167     if( !p_inpic )
 168         return NULL;
 169
 170     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 171     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 172
 173     if( !p_sys->b_old )
 174     {
 175         picture_Copy( p_sys->p_old, p_inpic );
 176         p_sys->b_old = true;
 177         return p_inpic;
 178     }
 179
 180     p_outpic = filter_NewPicture( p_filter );
 181     if( !p_outpic )
 182     {
 183         picture_Release( p_inpic );
 184         return NULL;
 185     }
 186     picture_Copy( p_outpic, p_inpic );
 187
 188     /**
 189      * Substract Y planes
 190      */
 191     for( y = 0; y < p_fmt->i_height; y++ )
 192     {
 193         for( x = 0; x < p_fmt->i_width; x++ )
 194             p_buf2[y*p_fmt->i_width+x] = abs( p_inpix[y*i_src_pitch+x] - p_oldpix[y*i_old_pitch+x] );
 195     }
 196
 197     int i_chroma_dx;
 198     int i_chroma_dy;
 199     switch( p_inpic->format.i_chroma )
 200     {
 201         case VLC_FOURCC('I','4','2','0'):
 202         case VLC_FOURCC('I','Y','U','V'):
 203         case VLC_FOURCC('J','4','2','0'):
 204         case VLC_FOURCC('Y','V','1','2'):
 205             i_chroma_dx = 2;
 206             i_chroma_dy = 2;
 207             break;
 208
 209         case VLC_FOURCC('I','4','2','2'):
 210         case VLC_FOURCC('J','4','2','2'):
 211             i_chroma_dx = 2;
 212             i_chroma_dy = 1;
 213             break;
 214
 215         default:
 216             msg_Warn( p_filter, "Not taking chroma into account" );
 217             i_chroma_dx = 0;
 218             i_chroma_dy = 0;
 219             break;
 220     }
 221
 222     if( i_chroma_dx != 0 && i_chroma_dy != 0 )
 223     {
 224         const uint8_t *p_inpix_u = p_inpic->p[U_PLANE].p_pixels;
 225         const uint8_t *p_inpix_v = p_inpic->p[V_PLANE].p_pixels;
 226         const int i_src_pitch_u = p_inpic->p[U_PLANE].i_pitch;
 227         const int i_src_pitch_v = p_inpic->p[V_PLANE].i_pitch;
 228
 229         const uint8_t *p_oldpix_u = p_sys->p_old->p[U_PLANE].p_pixels;
 230         const uint8_t *p_oldpix_v = p_sys->p_old->p[V_PLANE].p_pixels;
 231         const int i_old_pitch_u = p_sys->p_old->p[U_PLANE].i_pitch;
 232         const int i_old_pitch_v = p_sys->p_old->p[V_PLANE].i_pitch;
 233
 234         for( y = 0; y < p_fmt->i_height/i_chroma_dy; y++ )
 235         {
 236             for( x = 0; x < p_fmt->i_width/i_chroma_dx; x ++ )
 237             {
 238                 const int d = abs( p_inpix_u[y*i_src_pitch_u+x] - p_oldpix_u[y*i_old_pitch_u+x] ) +
 239                               abs( p_inpix_v[y*i_src_pitch_v+x] - p_oldpix_v[y*i_old_pitch_v+x] );
 240                 int i, j;
 241
 242                 for( j = 0; j < i_chroma_dy; j++ )
 243                 {
 244                     for( i = 0; i < i_chroma_dx; i++ )
 245                         p_buf2[i_chroma_dy*p_fmt->i_width*j + i_chroma_dx*i] = d;
 246                 }
 247             }
 248         }
 249     }
 250
 251     /**
 252      * Get the areas where movement was detected
 253      */
 254     p_sys->i_colors = FindShapes( p_buf2, p_buf, p_fmt->i_width, p_fmt->i_width, p_fmt->i_height,
 255                                   p_sys->colors, p_sys->color_x_min, p_sys->color_x_max, p_sys->color_y_min, p_sys->color_y_max );
 256
 257     /**
 258      * Count final number of shapes
 259      * Draw rectangles (there can be more than 1 moving shape in 1 rectangle)
 260      */
 261     Draw( p_filter, p_outpic->p[Y_PLANE].p_pixels, p_outpic->p[Y_PLANE].i_pitch, 1 );
 262
 263     /**
 264      * We're done. Lets keep a copy of the picture
 265      * TODO we may just picture_Release with a latency of 1 if the filters/vout
 266      * handle it correctly */
 267     picture_Copy( p_sys->p_old, p_inpic );
 268
 269     picture_Release( p_inpic );
 270     return p_outpic;
 271 }
 272
 273 /*****************************************************************************
 274  * Filter YUV Packed
 275  *****************************************************************************/
 276 static picture_t *FilterPacked( filter_t *p_filter, picture_t *p_inpic )
 277 {
 278     filter_sys_t *p_sys = p_filter->p_sys;
 279     const video_format_t *p_fmt = &p_filter->fmt_in.video;
 280     picture_t *p_outpic;
 281
 282     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 283     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 284
 285     uint8_t *p_oldpix   = p_sys->p_old->p[Y_PLANE].p_pixels;
 286     const int i_old_pitch = p_sys->p_old->p[Y_PLANE].i_pitch;
 287     uint32_t *p_buf = p_sys->p_buf;
 288     uint32_t *p_buf2= p_sys->p_buf2;
 289
 290     int i_y_offset, i_u_offset, i_v_offset;
 291
 292     unsigned x, y;
 293
 294     if( GetPackedYuvOffsets( p_fmt->i_chroma,
 295                              &i_y_offset, &i_u_offset, &i_v_offset ) )
 296     {
 297         msg_Warn( p_filter, "Unsupported input chroma (%4s)",
 298                   (char*)&p_fmt->i_chroma );
 299         return p_inpic;
 300     }
 301
 302     if( !p_sys->b_old )
 303     {
 304         picture_Copy( p_sys->p_old, p_inpic );
 305         p_sys->b_old = true;
 306         return p_inpic;
 307     }
 308
 309     p_outpic = filter_NewPicture( p_filter );
 310     if( !p_outpic )
 311     {
 312         picture_Release( p_inpic );
 313         return NULL;
 314     }
 315     picture_Copy( p_outpic, p_inpic );
 316
 317     /* Substract all planes at once */
 318
 319     for( y = 0; y < p_fmt->i_height; y++ )
 320     {
 321         for( x = 0; x < p_fmt->i_width; x+=2 )
 322         {
 323             int i;
 324             int d;
 325
 326             d = abs( p_inpix[y*i_src_pitch+2*x+i_u_offset] - p_oldpix[y*i_old_pitch+2*x+i_u_offset] ) +
 327                 abs( p_inpix[y*i_src_pitch+2*x+i_v_offset] - p_oldpix[y*i_old_pitch+2*x+i_v_offset] );
 328
 329             for( i = 0; i < 2; i++ )
 330                 p_buf2[y*p_fmt->i_width+x+i] =
 331                     abs( p_inpix[y*i_src_pitch+2*(x+i)+i_y_offset] - p_oldpix[y*i_old_pitch+2*(x+i)+i_y_offset] ) + d;
 332         }
 333     }
 334
 335     /**
 336      * Get the areas where movement was detected
 337      */
 338     p_sys->i_colors = FindShapes( p_buf2, p_buf, p_fmt->i_width, p_fmt->i_width, p_fmt->i_height,
 339                                   p_sys->colors, p_sys->color_x_min, p_sys->color_x_max, p_sys->color_y_min, p_sys->color_y_max );
 340
 341     /**
 342      * Count final number of shapes
 343      * Draw rectangles (there can be more than 1 moving shape in 1 rectangle)
 344      */
 345     Draw( p_filter, &p_outpic->p[Y_PLANE].p_pixels[i_y_offset], p_outpic->p[Y_PLANE].i_pitch, 2 );
 346
 347     /**
 348      * We're done. Lets keep a copy of the picture
 349      * TODO we may just picture_Release with a latency of 1 if the filters/vout
 350      * handle it correctly */
 351     picture_Copy( p_sys->p_old, p_inpic );
 352
 353     picture_Release( p_inpic );
 354     return p_outpic;
 355 }
 356
 357
 358
 359 /*****************************************************************************
 360  * Gaussian Convolution
 361  *****************************************************************************
 362  *    Gaussian convolution ( sigma == 1.4 )
 363  *
 364  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
 365  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
 366  *    |  5 12 15 12  5  | ~ |  4 12 16 12  4 |
 367  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
 368  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
 369  *****************************************************************************/
 370 static void GaussianConvolution( uint32_t *p_inpix, uint32_t *p_smooth,
 371                                  int i_src_pitch, int i_num_lines,
 372                                  int i_src_visible )
 373 {
 374     int x,y;
 375
 376     /* A bit overkill but ... simpler */
 377     memset( p_smooth, 0, sizeof(*p_smooth) * i_src_pitch * i_num_lines );
 378
 379     for( y = 2; y < i_num_lines - 2; y++ )
 380     {
 381         for( x = 2; x < i_src_visible - 2; x++ )
 382         {
 383             p_smooth[y*i_src_visible+x] = (uint32_t)(
 384               /* 2 rows up */
 385                 ( p_inpix[(y-2)*i_src_pitch+x-2] )
 386               + ((p_inpix[(y-2)*i_src_pitch+x-1]
 387               +   p_inpix[(y-2)*i_src_pitch+x]
 388               +   p_inpix[(y-2)*i_src_pitch+x+1])<<1 )
 389               + ( p_inpix[(y-2)*i_src_pitch+x+2] )
 390               /* 1 row up */
 391               + ((p_inpix[(y-1)*i_src_pitch+x-2]
 392               + ( p_inpix[(y-1)*i_src_pitch+x-1]<<1 )
 393               + ( p_inpix[(y-1)*i_src_pitch+x]*3 )
 394               + ( p_inpix[(y-1)*i_src_pitch+x+1]<<1 )
 395               +   p_inpix[(y-1)*i_src_pitch+x+2]
 396               /* */
 397               +   p_inpix[y*i_src_pitch+x-2]
 398               + ( p_inpix[y*i_src_pitch+x-1]*3 )
 399               + ( p_inpix[y*i_src_pitch+x]<<2 )
 400               + ( p_inpix[y*i_src_pitch+x+1]*3 )
 401               +   p_inpix[y*i_src_pitch+x+2]
 402               /* 1 row down */
 403               +   p_inpix[(y+1)*i_src_pitch+x-2]
 404               + ( p_inpix[(y+1)*i_src_pitch+x-1]<<1 )
 405               + ( p_inpix[(y+1)*i_src_pitch+x]*3 )
 406               + ( p_inpix[(y+1)*i_src_pitch+x+1]<<1 )
 407               +   p_inpix[(y+1)*i_src_pitch+x+2] )<<1 )
 408               /* 2 rows down */
 409               + ( p_inpix[(y+2)*i_src_pitch+x-2] )
 410               + ((p_inpix[(y+2)*i_src_pitch+x-1]
 411               +   p_inpix[(y+2)*i_src_pitch+x]
 412               +   p_inpix[(y+2)*i_src_pitch+x+1])<<1 )
 413               + ( p_inpix[(y+2)*i_src_pitch+x+2] )
 414               ) >> 6 /* 115 */;
 415         }
 416     }
 417 }
 418
 419 /*****************************************************************************
 420  *
 421  *****************************************************************************/
 422 static int FindShapes( uint32_t *p_diff, uint32_t *p_smooth,
 423                        int i_pitch, int i_visible, int i_lines,
 424                        int *colors,
 425                        int *color_x_min, int *color_x_max,
 426                        int *color_y_min, int *color_y_max )
 427 {
 428     int last = 1;
 429     int i, j;
 430
 431     /**
 432      * Apply some smoothing to remove noise
 433      */
 434     GaussianConvolution( p_diff, p_smooth, i_pitch, i_lines, i_visible );
 435
 436     /**
 437      * Label the shapes and build the labels dependencies list
 438      */
 439     for( j = 0; j < i_pitch; j++ )
 440     {
 441         p_smooth[j] = 0;
 442         p_smooth[(i_lines-1)*i_pitch+j] = 0;
 443     }
 444     for( i = 1; i < i_lines-1; i++ )
 445     {
 446         p_smooth[i*i_pitch] = 0;
 447         for( j = 1; j < i_pitch-1; j++ )
 448         {
 449             if( p_smooth[i*i_pitch+j] > 15 )
 450             {
 451                 if( p_smooth[(i-1)*i_pitch+j-1] )
 452                 {
 453                     p_smooth[i*i_pitch+j] = p_smooth[(i-1)*i_pitch+j-1];
 454                 }
 455                 else if( p_smooth[(i-1)*i_pitch+j] )
 456                     p_smooth[i*i_pitch+j] = p_smooth[(i-1)*i_pitch+j];
 457                 else if( p_smooth[i*i_pitch+j-1] )
 458                     p_smooth[i*i_pitch+j] = p_smooth[i*i_pitch+j-1];
 459                 else
 460                 {
 461                     if( last < NUM_COLORS )
 462                     {
 463                         p_smooth[i*i_pitch+j] = last;
 464                         colors[last] = last;
 465                         last++;
 466                     }
 467                 }
 468                 #define CHECK( A ) \
 469                 if( p_smooth[A] && p_smooth[A] != p_smooth[i*i_pitch+j] ) \
 470                 { \
 471                     if( p_smooth[A] < p_smooth[i*i_pitch+j] ) \
 472                         colors[p_smooth[i*i_pitch+j]] = p_smooth[A]; \
 473                     else \
 474                         colors[p_smooth[A]] = p_smooth[i*i_pitch+j]; \
 475                 }
 476                 CHECK( i*i_pitch+j-1 );
 477                 CHECK( (i-1)*i_pitch+j-1 );
 478                 CHECK( (i-1)*i_pitch+j );
 479                 CHECK( (i-1)*i_pitch+j+1 );
 480                 #undef CHECK
 481             }
 482             else
 483             {
 484                 p_smooth[i*i_pitch+j] = 0;
 485             }
 486         }
 487         p_smooth[i*i_pitch+j] = 0;
 488     }
 489
 490     /**
 491      * Initialise empty rectangle list
 492      */
 493     for( i = 1; i < last; i++ )
 494     {
 495         color_x_min[i] = -1;
 496         color_x_max[i] = -1;
 497         color_y_min[i] = -1;
 498         color_y_max[i] = -1;
 499     }
 500
 501     /**
 502      * Compute rectangle coordinates
 503      */
 504     for( i = 0; i < i_pitch * i_lines; i++ )
 505     {
 506         if( p_smooth[i] )
 507         {
 508             while( colors[p_smooth[i]] != (int)p_smooth[i] )
 509                 p_smooth[i] = colors[p_smooth[i]];
 510             if( color_x_min[p_smooth[i]] == -1 )
 511             {
 512                 color_x_min[p_smooth[i]] =
 513                 color_x_max[p_smooth[i]] = i % i_pitch;
 514                 color_y_min[p_smooth[i]] =
 515                 color_y_max[p_smooth[i]] = i / i_pitch;
 516             }
 517             else
 518             {
 519                 int x = i % i_pitch, y = i / i_pitch;
 520                 if( x < color_x_min[p_smooth[i]] )
 521                     color_x_min[p_smooth[i]] = x;
 522                 if( x > color_x_max[p_smooth[i]] )
 523                     color_x_max[p_smooth[i]] = x;
 524                 if( y < color_y_min[p_smooth[i]] )
 525                     color_y_min[p_smooth[i]] = y;
 526                 if( y > color_y_max[p_smooth[i]] )
 527                     color_y_max[p_smooth[i]] = y;
 528             }
 529         }
 530     }
 531
 532     /**
 533      * Merge overlaping rectangles
 534      */
 535     for( i = 1; i < last; i++ )
 536     {
 537         if( colors[i] != i ) continue;
 538         if( color_x_min[i] == -1 ) continue;
 539         for( j = i+1; j < last; j++ )
 540         {
 541             if( colors[j] != j ) continue;
 542             if( color_x_min[j] == -1 ) continue;
 543             if( __MAX( color_x_min[i], color_x_min[j] ) < __MIN( color_x_max[i], color_x_max[j] ) &&
 544                 __MAX( color_y_min[i], color_y_min[j] ) < __MIN( color_y_max[i], color_y_max[j] ) )
 545             {
 546                 color_x_min[i] = __MIN( color_x_min[i], color_x_min[j] );
 547                 color_x_max[i] = __MAX( color_x_max[i], color_x_max[j] );
 548                 color_y_min[i] = __MIN( color_y_min[i], color_y_min[j] );
 549                 color_y_max[i] = __MAX( color_y_max[i], color_y_max[j] );
 550                 color_x_min[j] = -1;
 551                 j = 0;
 552             }
 553         }
 554     }
 555
 556     return last;
 557 }
 558
 559 static void Draw( filter_t *p_filter, uint8_t *p_pix, int i_pix_pitch, int i_pix_size )
 560 {
 561     filter_sys_t *p_sys = p_filter->p_sys;
 562     int i, j;
 563
 564     for( i = 1, j = 0; i < p_sys->i_colors; i++ )
 565     {
 566         int x, y;
 567
 568         if( p_sys->colors[i] != i )
 569             continue;
 570
 571         const int color_x_min = p_sys->color_x_min[i];
 572         const int color_x_max = p_sys->color_x_max[i];
 573         const int color_y_min = p_sys->color_y_min[i];
 574         const int color_y_max = p_sys->color_y_max[i];
 575
 576         if( color_x_min == -1 )
 577             continue;
 578         if( ( color_y_max - color_y_min ) * ( color_x_max - color_x_min ) < 16 )
 579             continue;
 580
 581         j++;
 582
 583         y = color_y_min;
 584         for( x = color_x_min; x <= color_x_max; x++ )
 585             p_pix[y*i_pix_pitch+x*i_pix_size] = 0xff;
 586
 587         y = color_y_max;
 588         for( x = color_x_min; x <= color_x_max; x++ )
 589             p_pix[y*i_pix_pitch+x*i_pix_size] = 0xff;
 590
 591         x = color_x_min;
 592         for( y = color_y_min; y <= color_y_max; y++ )
 593             p_pix[y*i_pix_pitch+x*i_pix_size] = 0xff;
 594
 595         x = color_x_max;
 596         for( y = color_y_min; y <= color_y_max; y++ )
 597             p_pix[y*i_pix_pitch+x*i_pix_size] = 0xff;
 598     }
 599     msg_Dbg( p_filter, "Counted %d moving shapes.", j );
 600 }