Getting started with Shaders

Thanks for that tip on blendMode instead of blend. ( Even if this works I’m liable to continue digging into shaders though.) I forget, do I still need to specify OpenGL in the size for the latest version of Processing? And where should I put blendMode? This is what I’ve been using…which over time really gets my computer to heat up.

import processing.video.*;

Movie m1;
Movie m2;

void setup(){
  //size(800,800);
  fullScreen();
  m1 = new Movie(this, "zz.mov");
  m1.loop();
 // m1.speed(.7);
  
   m2 = new Movie(this, "aaa.mov");
  m2.loop();
// m2.speed(.8);
}

void movieEvent(Movie m){
  if (m == m1){
    m1.read(); }
    else{
      m2.read();
    }
}

void draw(){
  background(255);
  image(m1,0,0,width,height);
  blend(m2,0,0,1280,800, 0,0,1280,800,MULTIPLY);

}