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
  36 #include <vlc_filter.h>
  37 #include "filter_picture.h"
  38
  39 /*****************************************************************************
  40  * Module descriptor
  41  *****************************************************************************/
  42 static int  Create    ( vlc_object_t * );
  43 static void Destroy   ( vlc_object_t * );
  44
  45 #define FILTER_PREFIX "motiondetect-"
  46
  47 vlc_module_begin ()
  48     set_description( N_("Motion detect video filter") )
  49     set_shortname( N_( "Motion Detect" ))
  50     set_category( CAT_VIDEO )
  51     set_subcategory( SUBCAT_VIDEO_VFILTER )
  52     set_capability( "video filter2", 0 )
  53
  54     add_shortcut( "motion" )
  55     set_callbacks( Create, Destroy )
  56 vlc_module_end ()
  57
  58
  59 /*****************************************************************************
  60  * Local prototypes
  61  *****************************************************************************/
  62 static picture_t *Filter( filter_t *, picture_t * );
  63 static picture_t *FilterPacked( filter_t *, picture_t * );
  64 static void GaussianConvolution( uint32_t *, uint32_t *, int, int, int );
  65 static int FindShapes( uint32_t *, uint32_t *, int, int, int,
  66                        int *, int *, int *, int *, int *);
  67 static void Draw( filter_t *p_filter, uint8_t *p_pix, int i_pix_pitch, int i_pix_size );
  68 #define NUM_COLORS (5000)
  69
  70 struct filter_sys_t
  71 {
  72     bool b_old;
  73     picture_t *p_old;
  74     uint32_t *p_buf;
  75     uint32_t *p_buf2;
  76
  77     /* */
  78     int i_colors;
  79     int colors[NUM_COLORS];
  80     int color_x_min[NUM_COLORS];
  81     int color_x_max[NUM_COLORS];
  82     int color_y_min[NUM_COLORS];
  83     int color_y_max[NUM_COLORS];
  84 };
  85
  86 /*****************************************************************************
  87  * Create
  88  *****************************************************************************/
  89 static int Create( vlc_object_t *p_this )
  90 {
  91     filter_t *p_filter = (filter_t *)p_this;
  92     const video_format_t *p_fmt = &p_filter->fmt_in.video;
  93     filter_sys_t *p_sys;
  94
  95     switch( p_fmt->i_chroma )
  96     {
  97         CASE_PLANAR_YUV
  98             p_filter->pf_video_filter = Filter;
  99             break;
 100
 101         CASE_PACKED_YUV_422
 102             p_filter->pf_video_filter = FilterPacked;
 103             break;
 104
 105         default:
 106             msg_Err( p_filter, "Unsupported input chroma (%4.4s)",
 107                      (char*)&(p_fmt->i_chroma) );
 108             return VLC_EGENERIC;
 109     }
 110
 111     /* Allocate structure */
 112     p_filter->p_sys = p_sys = malloc( sizeof( filter_sys_t ) );
 113     if( p_filter->p_sys == NULL )
 114         return VLC_ENOMEM;
 115
 116     p_sys->b_old = false;
 117     p_sys->p_old = picture_NewFromFormat( p_fmt );
 118     p_sys->p_buf  = calloc( p_fmt->i_width * p_fmt->i_height, sizeof(*p_sys->p_buf) );
 119     p_sys->p_buf2 = calloc( p_fmt->i_width * p_fmt->i_height, sizeof(*p_sys->p_buf) );
 120
 121     if( !p_sys->p_old || !p_sys->p_buf || !p_sys->p_buf2 )
 122     {
 123         free( p_sys->p_buf2 );
 124         free( p_sys->p_buf );
 125         if( p_sys->p_old )
 126             picture_Release( p_sys->p_old );
 127         return VLC_ENOMEM;
 128     }
 129
 130     return VLC_SUCCESS;
 131 }
 132
 133 /*****************************************************************************
 134  * Destroy
 135  *****************************************************************************/
 136 static void Destroy( vlc_object_t *p_this )
 137 {
 138     filter_t *p_filter = (filter_t *)p_this;
 139     filter_sys_t *p_sys = p_filter->p_sys;
 140
 141     free( p_sys->p_buf2 );
 142     free( p_sys->p_buf );
 143     picture_Release( p_sys->p_old );
 144     free( p_sys );
 145 }
 146
 147
 148 /*****************************************************************************
 149  * Filter YUV Planar
 150  *****************************************************************************/
 151 static picture_t *Filter( filter_t *p_filter, picture_t *p_inpic )
 152 {
 153     filter_sys_t *p_sys = p_filter->p_sys;
 154     const video_format_t *p_fmt = &p_filter->fmt_in.video;
 155
 156     picture_t *p_outpic;
 157
 158     uint8_t *p_oldpix   = p_sys->p_old->p[Y_PLANE].p_pixels;
 159     const int i_old_pitch = p_sys->p_old->p[Y_PLANE].i_pitch;
 160     uint32_t *p_buf = p_sys->p_buf;
 161     uint32_t *p_buf2= p_sys->p_buf2;
 162
 163     unsigned x, y;
 164
 165     if( !p_inpic )
 166         return NULL;
 167
 168     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 169     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 170
 171     p_outpic = filter_NewPicture( p_filter );
 172     if( !p_outpic )
 173     {
 174         picture_Release( p_inpic );
 175         return NULL;
 176     }
 177     picture_Copy( p_outpic, p_inpic );
 178
 179     if( !p_sys->b_old )
 180     {
 181         picture_Copy( p_sys->p_old, p_inpic );
 182         picture_Release( p_inpic );
 183         p_sys->b_old = true;
 184         return p_outpic;
 185     }
 186
 187     /**
 188      * Substract Y planes
 189      */
 190     for( y = 0; y < p_fmt->i_height; y++ )
 191     {
 192         for( x = 0; x < p_fmt->i_width; x++ )
 193             p_buf2[y*p_fmt->i_width+x] = abs( p_inpix[y*i_src_pitch+x] - p_oldpix[y*i_old_pitch+x] );
 194     }
 195
 196     int i_chroma_dx;
 197     int i_chroma_dy;
 198     switch( p_inpic->format.i_chroma )
 199     {
 200         case VLC_CODEC_I420:
 201         case VLC_CODEC_J420:
 202         case VLC_CODEC_YV12:
 203             i_chroma_dx = 2;
 204             i_chroma_dy = 2;
 205             break;
 206
 207         case VLC_CODEC_I422:
 208         case VLC_CODEC_J422:
 209             i_chroma_dx = 2;
 210             i_chroma_dy = 1;
 211             break;
 212
 213         default:
 214             msg_Warn( p_filter, "Not taking chroma into account" );
 215             i_chroma_dx = 0;
 216             i_chroma_dy = 0;
 217             break;
 218     }
 219
 220     if( i_chroma_dx != 0 && i_chroma_dy != 0 )
 221     {
 222         const uint8_t *p_inpix_u = p_inpic->p[U_PLANE].p_pixels;
 223         const uint8_t *p_inpix_v = p_inpic->p[V_PLANE].p_pixels;
 224         const int i_src_pitch_u = p_inpic->p[U_PLANE].i_pitch;
 225         const int i_src_pitch_v = p_inpic->p[V_PLANE].i_pitch;
 226
 227         const uint8_t *p_oldpix_u = p_sys->p_old->p[U_PLANE].p_pixels;
 228         const uint8_t *p_oldpix_v = p_sys->p_old->p[V_PLANE].p_pixels;
 229         const int i_old_pitch_u = p_sys->p_old->p[U_PLANE].i_pitch;
 230         const int i_old_pitch_v = p_sys->p_old->p[V_PLANE].i_pitch;
 231
 232         for( y = 0; y < p_fmt->i_height/i_chroma_dy; y++ )
 233         {
 234             for( x = 0; x < p_fmt->i_width/i_chroma_dx; x ++ )
 235             {
 236                 const int d = abs( p_inpix_u[y*i_src_pitch_u+x] - p_oldpix_u[y*i_old_pitch_u+x] ) +
 237                               abs( p_inpix_v[y*i_src_pitch_v+x] - p_oldpix_v[y*i_old_pitch_v+x] );
 238                 int i, j;
 239
 240                 for( j = 0; j < i_chroma_dy; j++ )
 241                 {
 242                     for( i = 0; i < i_chroma_dx; i++ )
 243                         p_buf2[i_chroma_dy*p_fmt->i_width*j + i_chroma_dx*i] = d;
 244                 }
 245             }
 246         }
 247     }
 248
 249     /**
 250      * Get the areas where movement was detected
 251      */
 252     p_sys->i_colors = FindShapes( p_buf2, p_buf, p_fmt->i_width, p_fmt->i_width, p_fmt->i_height,
 253                                   p_sys->colors, p_sys->color_x_min, p_sys->color_x_max, p_sys->color_y_min, p_sys->color_y_max );
 254
 255     /**
 256      * Count final number of shapes
 257      * Draw rectangles (there can be more than 1 moving shape in 1 rectangle)
 258      */
 259     Draw( p_filter, p_outpic->p[Y_PLANE].p_pixels, p_outpic->p[Y_PLANE].i_pitch, 1 );
 260
 261     /**
 262      * We're done. Lets keep a copy of the picture
 263      * TODO we may just picture_Release with a latency of 1 if the filters/vout
 264      * handle it correctly */
 265     picture_Copy( p_sys->p_old, p_inpic );
 266
 267     picture_Release( p_inpic );
 268     return p_outpic;
 269 }
 270
 271 /*****************************************************************************
 272  * Filter YUV Packed
 273  *****************************************************************************/
 274 static picture_t *FilterPacked( filter_t *p_filter, picture_t *p_inpic )
 275 {
 276     filter_sys_t *p_sys = p_filter->p_sys;
 277     const video_format_t *p_fmt = &p_filter->fmt_in.video;
 278     picture_t *p_outpic;
 279
 280     const uint8_t *p_inpix = p_inpic->p[Y_PLANE].p_pixels;
 281     const int i_src_pitch = p_inpic->p[Y_PLANE].i_pitch;
 282
 283     uint8_t *p_oldpix   = p_sys->p_old->p[Y_PLANE].p_pixels;
 284     const int i_old_pitch = p_sys->p_old->p[Y_PLANE].i_pitch;
 285     uint32_t *p_buf = p_sys->p_buf;
 286     uint32_t *p_buf2= p_sys->p_buf2;
 287
 288     int i_y_offset, i_u_offset, i_v_offset;
 289
 290     unsigned x, y;
 291
 292     if( GetPackedYuvOffsets( p_fmt->i_chroma,
 293                              &i_y_offset, &i_u_offset, &i_v_offset ) )
 294     {
 295         msg_Warn( p_filter, "Unsupported input chroma (%4.4s)",
 296                   (char*)&p_fmt->i_chroma );
 297         return p_inpic;
 298     }
 299
 300     if( !p_sys->b_old )
 301     {
 302         picture_Copy( p_sys->p_old, p_inpic );
 303         p_sys->b_old = true;
 304         return p_inpic;
 305     }
 306
 307     p_outpic = filter_NewPicture( p_filter );
 308     if( !p_outpic )
 309     {
 310         picture_Release( p_inpic );
 311         return NULL;
 312     }
 313     picture_Copy( p_outpic, p_inpic );
 314
 315     /* Substract all planes at once */
 316
 317     for( y = 0; y < p_fmt->i_height; y++ )
 318     {
 319         for( x = 0; x < p_fmt->i_width; x+=2 )
 320         {
 321             int i;
 322             int d;
 323
 324             d = abs( p_inpix[y*i_src_pitch+2*x+i_u_offset] - p_oldpix[y*i_old_pitch+2*x+i_u_offset] ) +
 325                 abs( p_inpix[y*i_src_pitch+2*x+i_v_offset] - p_oldpix[y*i_old_pitch+2*x+i_v_offset] );
 326
 327             for( i = 0; i < 2; i++ )
 328                 p_buf2[y*p_fmt->i_width+x+i] =
 329                     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;
 330         }
 331     }
 332
 333     /**
 334      * Get the areas where movement was detected
 335      */
 336     p_sys->i_colors = FindShapes( p_buf2, p_buf, p_fmt->i_width, p_fmt->i_width, p_fmt->i_height,
 337                                   p_sys->colors, p_sys->color_x_min, p_sys->color_x_max, p_sys->color_y_min, p_sys->color_y_max );
 338
 339     /**
 340      * Count final number of shapes
 341      * Draw rectangles (there can be more than 1 moving shape in 1 rectangle)
 342      */
 343     Draw( p_filter, &p_outpic->p[Y_PLANE].p_pixels[i_y_offset], p_outpic->p[Y_PLANE].i_pitch, 2 );
 344
 345     /**
 346      * We're done. Lets keep a copy of the picture
 347      * TODO we may just picture_Release with a latency of 1 if the filters/vout
 348      * handle it correctly */
 349     picture_Copy( p_sys->p_old, p_inpic );
 350
 351     picture_Release( p_inpic );
 352     return p_outpic;
 353 }
 354
 355
 356
 357 /*****************************************************************************
 358  * Gaussian Convolution
 359  *****************************************************************************
 360  *    Gaussian convolution ( sigma == 1.4 )
 361  *
 362  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
 363  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
 364  *    |  5 12 15 12  5  | ~ |  4 12 16 12  4 |
 365  *    |  4  9 12  9  4  |   |  4  8 12  8  4 |
 366  *    |  2  4  5  4  2  |   |  2  4  4  4  2 |
 367  *****************************************************************************/
 368 static void GaussianConvolution( uint32_t *p_inpix, uint32_t *p_smooth,
 369                                  int i_src_pitch, int i_num_lines,
 370                                  int i_src_visible )
 371 {
 372     int x,y;
 373
 374     /* A bit overkill but ... simpler */
 375     memset( p_smooth, 0, sizeof(*p_smooth) * i_src_pitch * i_num_lines );
 376
 377     for( y = 2; y < i_num_lines - 2; y++ )
 378     {
 379         for( x = 2; x < i_src_visible - 2; x++ )
 380         {
 381             p_smooth[y*i_src_visible+x] = (uint32_t)(
 382               /* 2 rows up */
 383                 ( p_inpix[(y-2)*i_src_pitch+x-2] )
 384               + ((p_inpix[(y-2)*i_src_pitch+x-1]
 385               +   p_inpix[(y-2)*i_src_pitch+x]
 386               +   p_inpix[(y-2)*i_src_pitch+x+1])<<1 )
 387               + ( p_inpix[(y-2)*i_src_pitch+x+2] )
 388               /* 1 row up */
 389               + ((p_inpix[(y-1)*i_src_pitch+x-2]
 390               + ( p_inpix[(y-1)*i_src_pitch+x-1]<<1 )
 391               + ( p_inpix[(y-1)*i_src_pitch+x]*3 )
 392               + ( p_inpix[(y-1)*i_src_pitch+x+1]<<1 )
 393               +   p_inpix[(y-1)*i_src_pitch+x+2]
 394               /* */
 395               +   p_inpix[y*i_src_pitch+x-2]
 396               + ( p_inpix[y*i_src_pitch+x-1]*3 )
 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               /* 1 row down */
 401               +   p_inpix[(y+1)*i_src_pitch+x-2]
 402               + ( p_inpix[(y+1)*i_src_pitch+x-1]<<1 )
 403               + ( p_inpix[(y+1)*i_src_pitch+x]*3 )
 404               + ( p_inpix[(y+1)*i_src_pitch+x+1]<<1 )
 405               +   p_inpix[(y+1)*i_src_pitch+x+2] )<<1 )
 406               /* 2 rows down */
 407               + ( p_inpix[(y+2)*i_src_pitch+x-2] )
 408               + ((p_inpix[(y+2)*i_src_pitch+x-1]
 409               +   p_inpix[(y+2)*i_src_pitch+x]
 410               +   p_inpix[(y+2)*i_src_pitch+x+1])<<1 )
 411               + ( p_inpix[(y+2)*i_src_pitch+x+2] )
 412               ) >> 6 /* 115 */;
 413         }
 414     }
 415 }
 416
 417 /*****************************************************************************
 418  *
 419  *****************************************************************************/
 420 static int FindShapes( uint32_t *p_diff, uint32_t *p_smooth,
 421                        int i_pitch, int i_visible, int i_lines,
 422                        int *colors,
 423                        int *color_x_min, int *color_x_max,
 424                        int *color_y_min, int *color_y_max )
 425 {
 426     int last = 1;
 427     int i, j;
 428
 429     /**
 430      * Apply some smoothing to remove noise
 431      */
 432     GaussianConvolution( p_diff, p_smooth, i_pitch, i_lines, i_visible );
 433
 434     /**
 435      * Label the shapes and build the labels dependencies list
 436      */
 437     for( j = 0; j < i_pitch; j++ )
 438     {
 439         p_smooth[j] = 0;
 440         p_smooth[(i_lines-1)*i_pitch+j] = 0;
 441     }
 442     for( i = 1; i < i_lines-1; i++ )
 443     {
 444         p_smooth[i*i_pitch] = 0;
 445         for( j = 1; j < i_pitch-1; j++ )
 446         {
 447             if( p_smooth[i*i_pitch+j] > 15 )
 448             {
 449                 if( p_smooth[(i-1)*i_pitch+j-1] )
 450                 {
 451                     p_smooth[i*i_pitch+j] = p_smooth[(i-1)*i_pitch+j-1];
 452                 }
 453                 else if( p_smooth[(i-1)*i_pitch+j] )
 454                     p_smooth[i*i_pitch+j] = p_smooth[(i-1)*i_pitch+j];
 455                 else if( p_smooth[i*i_pitch+j-1] )
 456                     p_smooth[i*i_pitch+j] = p_smooth[i*i_pitch+j-1];
 457                 else
 458                 {
 459                     if( last < NUM_COLORS )
 460                     {
 461                         p_smooth[i*i_pitch+j] = last;
 462                         colors[last] = last;
 463                         last++;
 464                     }
 465                 }
 466                 #define CHECK( A ) \
 467                 if( p_smooth[A] && p_smooth[A] != p_smooth[i*i_pitch+j] ) \
 468                 { \
 469                     if( p_smooth[A] < p_smooth[i*i_pitch+j] ) \
 470                         colors[p_smooth[i*i_pitch+j]] = p_smooth[A]; \
 471                     else \
 472                         colors[p_smooth[A]] = p_smooth[i*i_pitch+j]; \
 473                 }
 474                 CHECK( i*i_pitch+j-1 );
 475                 CHECK( (i-1)*i_pitch+j-1 );
 476                 CHECK( (i-1)*i_pitch+j );
 477                 CHECK( (i-1)*i_pitch+j+1 );
 478                 #undef CHECK
 479             }
 480             else
 481             {
 482                 p_smooth[i*i_pitch+j] = 0;
 483             }
 484         }
 485         p_smooth[i*i_pitch+j] = 0;
 486     }
 487
 488     /**
 489      * Initialise empty rectangle list
 490      */
 491     for( i = 1; i < last; i++ )
 492     {
 493         color_x_min[i] = -1;
 494         color_x_max[i] = -1;
 495         color_y_min[i] = -1;
 496         color_y_max[i] = -1;
 497     }
 498
 499     /**
 500      * Compute rectangle coordinates
 501      */
 502     for( i = 0; i < i_pitch * i_lines; i++ )
 503     {
 504         if( p_smooth[i] )
 505         {
 506             while( colors[p_smooth[i]] != (int)p_smooth[i] )
 507                 p_smooth[i] = colors[p_smooth[i]];
 508             if( color_x_min[p_smooth[i]] == -1 )
 509             {
 510                 color_x_min[p_smooth[i]] =
 511                 color_x_max[p_smooth[i]] = i % i_pitch;
 512                 color_y_min[p_smooth[i]] =
 513                 color_y_max[p_smooth[i]] = i / i_pitch;
 514             }
 515             else
 516             {
 517                 int x = i % i_pitch, y = i / i_pitch;
 518                 if( x < color_x_min[p_smooth[i]] )
 519                     color_x_min[p_smooth[i]] = x;
 520                 if( x > color_x_max[p_smooth[i]] )
 521                     color_x_max[p_smooth[i]] = x;
 522                 if( y < color_y_min[p_smooth[i]] )
 523                     color_y_min[p_smooth[i]] = y;
 524                 if( y > color_y_max[p_smooth[i]] )
 525                     color_y_max[p_smooth[i]] = y;
 526             }
 527         }
 528     }
 529
 530     /**
 531      * Merge overlaping rectangles
 532      */
 533     for( i = 1; i < last; i++ )
 534     {
 535         if( colors[i] != i ) continue;
 536         if( color_x_min[i] == -1 ) continue;
 537         for( j = i+1; j < last; j++ )
 538         {
 539             if( colors[j] != j ) continue;
 540             if( color_x_min[j] == -1 ) continue;
 541             if( __MAX( color_x_min[i], color_x_min[j] ) < __MIN( color_x_max[i], color_x_max[j] ) &&
 542                 __MAX( color_y_min[i], color_y_min[j] ) < __MIN( color_y_max[i], color_y_max[j] ) )
 543             {
 544                 color_x_min[i] = __MIN( color_x_min[i], color_x_min[j] );
 545                 color_x_max[i] = __MAX( color_x_max[i], color_x_max[j] );
 546                 color_y_min[i] = __MIN( color_y_min[i], color_y_min[j] );
 547                 color_y_max[i] = __MAX( color_y_max[i], color_y_max[j] );
 548                 color_x_min[j] = -1;
 549                 j = 0;
 550             }
 551         }
 552     }
 553
 554     return last;
 555 }
 556
 557 static void Draw( filter_t *p_filter, uint8_t *p_pix, int i_pix_pitch, int i_pix_size )
 558 {
 559     filter_sys_t *p_sys = p_filter->p_sys;
 560     int i, j;
 561
 562     for( i = 1, j = 0; i < p_sys->i_colors; i++ )
 563     {
 564         int x, y;
 565
 566         if( p_sys->colors[i] != i )
 567             continue;
 568
 569         const int color_x_min = p_sys->color_x_min[i];
 570         const int color_x_max = p_sys->color_x_max[i];
 571         const int color_y_min = p_sys->color_y_min[i];
 572         const int color_y_max = p_sys->color_y_max[i];
 573
 574         if( color_x_min == -1 )
 575             continue;
 576         if( ( color_y_max - color_y_min ) * ( color_x_max - color_x_min ) < 16 )
 577             continue;
 578
 579         j++;
 580
 581         y = color_y_min;
 582         for( x = color_x_min; x <= color_x_max; x++ )
 583             p_pix[y*i_pix_pitch+x*i_pix_size] = 0xff;
 584
 585         y = color_y_max;
 586         for( x = color_x_min; x <= color_x_max; x++ )
 587             p_pix[y*i_pix_pitch+x*i_pix_size] = 0xff;
 588
 589         x = color_x_min;
 590         for( y = color_y_min; y <= color_y_max; y++ )
 591             p_pix[y*i_pix_pitch+x*i_pix_size] = 0xff;
 592
 593         x = color_x_max;
 594         for( y = color_y_min; y <= color_y_max; y++ )
 595             p_pix[y*i_pix_pitch+x*i_pix_size] = 0xff;
 596     }
 597     msg_Dbg( p_filter, "Counted %d moving shapes.", j );
 598 }