The MediaStream.getTrackById()
method returns a MediaStreamTrack
object representing the track with the specified ID string. If there is no track with the specified ID, this method returns null
.
Syntax
var track = MediaStream.getTrackById(id);
Parameters
id
- A
DOMString
which identifies the track to be returned.
Return value
If a track is found for which MediaStreamTrack.id
matches the specified id
string, that MediaStreamTrack
object is returned. Otherwise, the returned value is null
.
Example
This example activates a commentary track on a video by ducking the audio level of the main audio track to 50%, then enabling the commentary track.
stream.getTrackById("primary-audio-track").applyConstraints({ volume: 0.5 }); stream.getTrackById("commentary-track").enabled = true;
Specifications
Specification | Status | Comment |
---|---|---|
Media Capture and Streams The definition of 'getTrackById()' in that specification. |
Candidate Recommendation | Initial specification. |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
getTrackById | Chrome Full support 26 | Edge Full support 12 | Firefox Full support 49 | IE No support No | Opera No support No | Safari Full support Yes | WebView Android Full support 37 | Chrome Android Full support 26 | Firefox Android Full support 49 | Opera Android No support No | Safari iOS Full support Yes | Samsung Internet Android Full support 1.5 |
Legend
- Full support
- Full support
- No support
- No support