RTCPeerConnection: addstream event

Deprecated

Avoid using this feature in new projects. This feature may be a candidate for removal from web standards or browsers.

Non-standard: This feature is not standardized. We do not recommend using non-standard features in production, as they have limited browser support, and may change or be removed. However, they can be a suitable alternative in specific cases where no standard option exists.

The obsolete addstream event is sent to an RTCPeerConnection when new media, in the form of a MediaStream object, has been added to it.

Warning: This event has been removed from the WebRTC specification. You should instead watch for the track event, which is sent for each media track added to the RTCPeerConnection.

You can, similarly, watch for streams to be removed from the connection by monitoring the removestream event.

This event is not cancelable and does not bubble.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

js
addEventListener("addstream", (event) => { })

onaddstream = (event) => { }

Event type

A MediaStreamEvent. Inherits from Event.

Examples

This example looks to determine if the user's browser supports the track event. If it does, a track event listener is set up; otherwise, an addstream event listener is set up. pc is an RTCPeerConnection.

js
if (pc.addTrack !== undefined) {
  pc.ontrack = (ev) => {
    ev.streams.forEach((stream) => doAddStream(stream));
  };
} else {
  pc.onaddstream = (ev) => {
    doAddStream(ev.stream);
  };
}

This calls a function doAddStream() once for each stream being added to the RTCPeerConnection, regardless of whether the browser sends addstream or track.

You can also use the addEventListener() method to set an event listener:

js
pc.addEventListener("addstream", (ev) => doAddStream(ev.stream), false);

Browser compatibility

See also