I am trying to run a motion detection script using the default processing video library. The problem is that when I use the OpenGL renderer, the screen turns white and the code does not work anymore.

I really need to use OpenGL, since my program needs a fast renderer.

Does anyone know a way to make the two libraries work together?

Below is my isolated code for motion detection (it works fine without OpenGL):

1. import processing.opengl.*;
2. import processing.video.*;
3. // Variable for capture device
4. Capture video;
5. // Previous Frame
6. PImage prevFrame;
7. // How different must a pixel be to be a "motion" pixel
8. float threshold = 50;
9. 
   
10. // Count motion pixels to detect motion
11. HashMap pixeisEmMovimento = new HashMap();
12. boolean motionDetected = false;
13. int contagemMovimento;
14. 
    
15. void setup() {
16.   size(320,240, OPENGL);
17.   video = new Capture(this, width, height, 30);
18.   // Create an empty image the same size as the video
19.   prevFrame = createImage(video.width,video.height,RGB);
20. }
21. 
    
22. void draw() {
23.   
24.   // Capture video
25.   if (video.available()) {
26.     // Save previous frame for motion detection!!
27.     prevFrame.copy(video,0,0,video.width,video.height,0,0,video.width,video.height); // Before we read the new frame, we always save the previous frame for comparison!
28.     prevFrame.updatePixels();
29.     video.read();
30.   }
31.   
32.   loadPixels();
33.   video.loadPixels();
34.   prevFrame.loadPixels();
35.   
36.   // Begin loop to walk through every pixel
37.   for (int x = 0; x < video.width; x ++ ) {
38.     for (int y = 0; y < video.height; y ++ ) {
39.       
40.       int loc = x + y*video.width;            // Step 1, what is the 1D pixel location
41.       color current = video.pixels[loc];      // Step 2, what is the current color
42.       color previous = prevFrame.pixels[loc]; // Step 3, what is the previous color
43.       
44.       // Step 4, compare colors (previous vs. current)
45.       float r1 = red(current); float g1 = green(current); float b1 = blue(current);
46.       float r2 = red(previous); float g2 = green(previous); float b2 = blue(previous);
47.       float diff = dist(r1,g1,b1,r2,g2,b2);
48.       
49.       // Step 5, How different are the colors?
50.       // If the color at that pixel has changed, then there is motion at that pixel.
51.       if (diff > threshold) { 
52.         // If motion, display black
53.         pixels[loc] = color(0);
54.         pixeisEmMovimento.put(loc, "coiso");
55.       } else {
56.         // If not, display white
57.         pixels[loc] = color(255);
58.         pixeisEmMovimento.remove(loc);
59.       }
60.     }
61.   }
62.   
63.   if(contagemMovimento < 15) {
64.     contagemMovimento++;
65.   } else {
66.     if(pixeisEmMovimento.size() > 0) {
67.       motionDetected = true;
68.     } else {
69.       motionDetected = false;
70.     }
71.     contagemMovimento = 0;
72.   }
73.   
74.   println(motionDetected);
75. }