VideoTrackList: length property
Limited availability
This feature is not Baseline because it does not work in some of the most widely-used browsers.
The read-only VideoTrackList
property length returns the number of entries in the
VideoTrackList, each of which is a VideoTrack representing
one video track in the media element.
A value of 0 indicates that there are no video tracks in the media.
Value
A number indicating how many video tracks are included in the
VideoTrackList. Each track can be accessed by treating the
VideoTrackList as an array of objects of type VideoTrack.
Examples
This snippet gets the number of video tracks in the first <video>
element found in the DOM by querySelector().
const videoElem = document.querySelector("video");
let numVideoTracks = 0;
if (videoElem.videoTracks) {
numVideoTracks = videoElem.videoTracks.length;
}
Note that this sample checks to be sure HTMLMediaElement.videoTracks is
defined, to avoid failing on browsers without support for VideoTrack.
Specifications
| Specification |
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| HTML # dom-videotracklist-length-dev |
Browser compatibility
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Legend
Tip: you can click/tap on a cell for more information.
- Full support
- Full support
- No support
- No support
- User must explicitly enable this feature.
- Has more compatibility info.