SOURCE

let capture;
function setup() {
 createCanvas(640, 480);
 capture = createCapture(VIDEO);
 capture.hide();
 background(220);
}

function draw() {
 push();
  image(capture,0,0,320,240);
 pop();
 
 push();
 translate(640,0);
 scale(-1,1);
 image(capture,0,0,320,240);
 pop();
	
	push();
	translate(0,640);
	scale(1,-1);
	image(capture,0,160,320,240);
	pop();
	
	push();
	translate(760,640);
	scale(-1,-1);
	image(capture,120,160,320,240);
	pop();
	
	
}