VideoTrack
The VideoTrack
interface represents a single video track from a <video>
element.
The most common use for accessing a VideoTrack
object is to toggle its selected
property in order to make it the active video track for its <video>
element.
Instance properties
selected
-
A Boolean value which controls whether or not the video track is active. Only a single video track can be active at any given time, so setting this property to
true
for one track while another track is active will make that other track inactive. id
Read only-
A string which uniquely identifies the track within the media. This ID can be used to locate a specific track within a video track list by calling
VideoTrackList.getTrackById()
. The ID can also be used as the fragment part of the URL if the media supports seeking by media fragment per the Media Fragments URI specification. kind
Read only-
A string specifying the category into which the track falls. For example, the main video track would have a
kind
of"main"
. label
Read only-
A string providing a human-readable label for the track. For example, a track whose
kind
is"sign"
might have alabel
of"A sign-language interpretation"
. This string is empty if no label is provided. language
Read only-
A string specifying the video track's primary language, or an empty string if unknown. The language is specified as a BCP 47 (RFC 5646) language code, such as
"en-US"
or"pt-BR"
. sourceBuffer
Read only-
The
SourceBuffer
that created the track. Returns null if the track was not created by aSourceBuffer
or theSourceBuffer
has been removed from theMediaSource.sourceBuffers
attribute of its parent media source.
Usage notes
To get a VideoTrack
for a given media element, use the element's videoTracks
property, which returns a VideoTrackList
object from which you can get the individual tracks contained in the media:
js
const el = document.querySelector("video");
const tracks = el.videoTracks;
You can then access the media's individual tracks using either array syntax or functions such as forEach()
.
This first example gets the first video track on the media:
js
const firstTrack = tracks[0];
The next example scans through all of the media's video tracks, activating the first video track that is in the user's preferred language (taken from a variable userLanguage
).
js
for (const track of tracks) {
if (track.language === userLanguage) {
track.selected = true;
break;
}
}
The language
is in standard (RFC 5646) format. For US English, this would be "en-US"
, for example.
Specifications
Specification |
---|
HTML Standard # videotrack |
Browser compatibility
BCD tables only load in the browser