RTCPeerConnection.ontrack
This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
The RTCPeerConnection.ontrack
property is an EventHandler
which specifies a function to be called when the track
event occurs on an RTCPeerConnection
interface. The function receives as input the event object, of type RTCTrackEvent
; this event is sent when a new incoming MediaStreamTrack
has been created and associated with an RTCRtpReceiver
object which has been added to the set of receivers on connection.
Syntax
RTCPeerConnection.ontrack = errorHandler;
Value
Set ontrack
to be a function you provide that accepts as input a RTCTrackEvent
object describing the new track and how it's being used. This information includes the MediaStreamTrack
object representing the new track, the RTCRtpReceiver
and RTCRtpTransceiver
, and a list of MediaStream
objects which indicates which stream or streams the track is part of..
Example
This example, taken from the code for the article Signaling and video calling, connects the incoming track to the <video>
element which will be used to display the incoming video.
pc.ontrack = function(event) { document.getElementById("received_video").srcObject = event.streams[0]; document.getElementById("hangup-button").disabled = false; };
The first line of our ontrack
event handler takes the first stream in the incoming track and sets the srcobject
attribute to that. This connects that stream of video to the element so that it begins to be presented to the user. The second line of code simply enables a "hang up" button, which the user can use to disconnect from the call.
Specifications
Specification | Status | Comment |
---|---|---|
WebRTC 1.0: Real-time Communication Between Browser The definition of 'RTCPeerConnection.ontrack' in that specification. |
Working Draft | Initial specification. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | No support | 46 (46)[1] | No support | ? | ? |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | No support | No support | 46 (46)[1] | No support | ? | ? |
[1] Introduced in Firefox 45 as onaddtrack
; renamed to ontrack
in Firefox 46
See also
- The
track
event and its type,RTCTrackEvent
.
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/rtcpeerconnection/ontrack