Programming WebRTC

Refining the Initial Properties on Self and Peer

Let’s refresh our memories about the requestUserMedia() function you built back in ​Requesting User-Media Permissions​. Recall that it looked like this:

async function requestUserMedia(media_constraints) {
  $self.mediaStream = new MediaStream();
  $self.media = await navigator.mediaDevices
    .getUserMedia(media_constraints);
  $self.mediaStream.addTrack($self.media.getTracks()[0]);
  displayStream($self.mediaStream, '#self');
}

That function has the effect of requesting user permission to access the devices you include in $self.mediaConstraints. So far, that’s been a single video device. Once a user grants permission for your app to access the camera, the function goes on to use ...