let mic;

let slider;

​

function setup() {

  createCanvas(640, 480);

  video = createCapture(VIDEO);

  video.size(width, height);

  mic = new p5.AudioIn();

  mic.start();

  slider = createSlider(0, 255, 100);

  slider.position(10, height + 10);

  slider.style('width', width - 20 + 'px');

}

​

function draw() {

  background(220);

  video.loadPixels();

  loadPixels();

  let volume = mic.getLevel();

  let threshold = map(volume, 0, 1, 0, 255);

  slider.value(threshold);

  for (let y = 0; y < height; y++) {

    for (let x = 0; x < width; x++) {

      let index = (x + y * width) * 4;

      let r = video.pixels[index + 0];

      let g = video.pixels[index + 1];

      let b = video.pixels[index + 2];

      let a = video.pixels[index + 3];

      let bright = (r + g + b) / 3;

      if (bright > threshold) {

        pixels[index + 0] = r;

        pixels[index + 1] = g;

        pixels[index + 2] = b;

        pixels[index + 3] = a;

      } else {

        pixels[index + 0] = 0;

        pixels[index + 1] = 0;

        pixels[index + 2] = 0;

        pixels[index + 3] = a;

      }

    }

  }

  updatePixels();

}

​

function keyPressed() {

  if (key == ' ') {

    saveCanvas('myCanvas', 'png');

  }

}

​