How to make a movie in processing

saving frames

boolean recording = false;
int counter = 0;
String[] myText = {"one"," ","two"," ","three"," ","four"," ","five"};
PFont monospaced;
void setup(){
  monospaced = loadFont("Monospaced.plain-48.vlw");
  size(640,480);
  frameRate(30);
  textFont(monospaced,24);
  textAlign(CENTER);
}

void draw() {
  background(0);
  fill(255);
  if(counter < myText.length && counter >= 0) text(myText[counter],width/2,height/2);
  if (recording) {
    saveFrame("output/frames####.png");
  }
}

void keyPressed() {  
  if (key == 'r' || key == 'R') {
    recording = !recording;
  }
  if ((key == 'n' || key == 'N') && counter < myText.length-1){
    counter++;
  }
  if ((key == 'p' || key == 'P') && counter > 0){
    counter--;
  }
}