Now that we know how to get a stream from the browser, we will cover configuring this stream using the first parameter of the getUserMedia API. This parameter expects an object of keys and values telling the browser how to look for and process streams coming from the connected devices. The first options we will cover are simply turning on or off the video or audio streams:

navigator.getUserMedia({ video: false, audio: true }, function (stream) {
  // Now our stream does not contain any video!
});

When you add this stream to the <video> element, it will now not show any video coming from the camera. You can also do the opposite and get just a video feed and no audio. This is great while developing a WebRTC application when you do not want to listen to yourself talk all day!