The obsolete RTCPeerConnection method addStream() adds a MediaStream as a local source of audio or video. Instead of using this obsolete method, you should instead use addTrack() once for each track you wish to send to the remote peer.

If the signalingState is set to closed, an InvalidStateError is raised. If the signalingState is set to stable, the event negotiationneeded is sent on the RTCPeerConnection to indicate that ICE negotiation must be repeated to consider the new stream.

mediaStream

A MediaStream object indicating the stream to add to the WebRTC peer connection.

None.

This simple example adds the audio and video stream coming from the user's camera to the connection.

navigator.mediaDevices.getUserMedia({ video: true, audio: true }, (stream) => {
  const pc = new RTCPeerConnection();
  pc.addStream(stream);
});

Compatibility allowing, you should update your code to instead use the addTrack() method:

navigator.getUserMedia({ video: true, audio: true }, (stream) => {
  const pc = new RTCPeerConnection();
  stream.getTracks().forEach((track) => {
    pc.addTrack(track, stream);
  });
});

The newer addTrack() API avoids confusion over whether later changes to the track-makeup of a stream affects a peer connection (they do not).

The exception is in Chrome, where addStream() does make the peer connection sensitive to later stream changes (though such changes do not fire the negotiationneeded event). If you are relying on the Chrome behavior, note that other browsers do not have it. You can write web compatible code using feature detection instead:

// Add a track to a stream and the peer connection said stream was added to:

stream.addTrack(track);
if (pc.addTrack) {
  pc.addTrack(track, stream);
} else {
  // If you have code listening for negotiationneeded events:
  setTimeout(() => pc.dispatchEvent(new Event("negotiationneeded")));
}

// Remove a track from a stream and the peer connection said stream was added to:

stream.removeTrack(track);
if (pc.removeTrack) {
  pc.removeTrack(pc.getSenders().find((sender) => sender.track === track));
} else {
  // If you have code listening for negotiationneeded events:
  setTimeout(() => pc.dispatchEvent(new Event("negotiationneeded")));
}

• WebRTC