Alpha Channel not Changing

I have two videos playing and want to have a fade transition between them. I access directly each pixel but no matter what the alpha value is there is no change. For now I just have my code prepared to fade from a specific video to the other. If I can make it fade  from this video to the other I will be able to adapt and fade for the video that currently will be playing.

Here is my code:

2. import processing.video.*;
3. 
   
4. Movie movie1, movie2;
5. float alpha;
6. 
   
7. void setup() {
8.   alpha = 255.0;
9.   size(320, 240, P2D);
10.   movie1 = new Movie(this, "Video1.mov");
11.   movie2 = new Movie(this, "Video2.mov");
12.   movie1.loop();
13.   movie2.loop();
14. }
15. 
    
16. void movieEvent(Movie mov) {
17.   mov.read();
18. }
19. 
    
20. void draw()  {
21.   if (fade) { // Fade Transition
22.     image(movie1, 0, 0, width, height);
23.     fade(movie1, movie2, movie1Playing);
24.   } else {
25.     image(movie2, 0, 0, width, height);
26.   }
27. }
28. 
    
29. void fade(Movie mov1, Movie mov2) {
30.   float r = 0.0;
31.   float g = 0.0;
32.   float b = 0.0;
33. 
    
34.   int x = 0;
35.   int y = 0;
36.   int pos = 0;
37.   
38.   loadPixels();
39.   mov1.loadPixels();
40.   mov2.loadPixels();
41.     
42.     if(alpha > 0) {
43.       alpha--;
44.     }
45.     
46.     for (x = 0; x < mov2.width; x++) {
47.       for (y = 0; y < mov2.height; y++ ) {
48. 
    
49.         pos = x + y*mov2.width;
50.         
51.         r = red(mov2.pixels[pos]);
52.         g = green(mov2.pixels[pos]);
53.         b = blue(mov2.pixels[pos]);
54.   
55.         color newColor = color(r,g,b, alpha);
56.         pixels[pos] = newColor;
57.       }
58.     } 
59.   
60.   updatePixels();
61. }
62. 
    
63. void keyPressed() {
64.   switch (key) {
65.     case 'f':
66.       fade = !fade;
67.       break;
68.   }
69. }

For this work I can't use libraries or the tint function, I have to directly access the pixels and modify them.

I don't know why it's not working. I would appreciate any help you can give me.

Thanks in advance!