The VideoTrackList
interface is used to represent a list of the video tracks contained within a <video>
element, with each track represented by a separate VideoTrack
object in the list.
Retrieve an instance of this object with HTMLMediaElement.videoTracks
. The individual tracks can be accessed using array syntax or functions such as forEach()
for example.
Properties
This interface also inherits properties from its parent interface, EventTarget
.
length
Read only- The number of tracks in the list.
selectedIndex
Read only- The index of the currently selected track, if any, or
−1
otherwise.
Event handlers
onaddtrack
- An event handler to be called when the
addtrack
event is fired, indicating that a new video track has been added to the media element. onchange
- An event handler to be called when the
change
event occurs — that is, when the value of theselected
property for a track has changed, due to the track being made active or inactive. onremovetrack
- An event handler to call when the
removetrack
event is sent, indicating that a video track has been removed from the media element.
Methods
This interface also inherits methods from its parent interface, EventTarget
.
getTrackById()
- Returns the
VideoTrack
found within theVideoTrackList
whoseid
matches the specified string. If no match is found,null
is returned.
Events
addtrack
- Fired when a new video track has been added to the media element.
Also available via theonaddtrack
property. change
- Fired when a video track has been made active or inactive.
Also available via theonchange
property. removetrack
- Fired when a new video track has been removed from the media element.
Also available via theonremovetrack
property.
Usage notes
In addition to being able to obtain direct access to the video tracks present on a media element, VideoTrackList
lets you set event handlers on the addtrack
and removetrack
events, so that you can detect when tracks are added to or removed from the media element's stream. See onaddtrack
and onremovetrack
for details and examples.
Examples
Getting a media element's video track list
To get a media element's VideoTrackList
, use its videoTracks
property.
var videoTracks = document.querySelector("video").videoTracks;
Monitoring track count changes
In this example, we have an app that displays information about the number of channels available. To keep it up to date, handlers for the addtrack
and removetrack
events are set up.
videoTracks.onaddtrack = updateTrackCount; videoTracks.onremovetrack = updateTrackCount; function updateTrackCount(event) { trackCount = videoTracks.length; drawTrackCountIndicator(trackCount); }
Specifications
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'VideoTrackList' in that specification. |
Living Standard |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
VideoTrackList | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
addtrack event | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
change event | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
getTrackById | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
length | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
onaddtrack | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
onchange | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
onremovetrack | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
removetrack event | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android Full support 45 | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
selectedIndex | Chrome
Full support
45
| Edge
Full support
79
| Firefox
Full support
33
| IE Full support 10 | Opera
Full support
32
| Safari Full support 6.1 | WebView Android No support No | Chrome Android
Full support
45
| Firefox Android
Full support
33
| Opera Android
Full support
32
| Safari iOS Full support 7 | Samsung Internet Android No support No |
Legend
- Full support
- Full support
- No support
- No support
- User must explicitly enable this feature.
- User must explicitly enable this feature.