AudioTrack
The AudioTrack
interface represents a single audio track from one of the HTML media elements, <audio>
or <video>
.
The most common use for accessing an AudioTrack
object is to toggle its enabled
property in order to mute and unmute the track.
Properties
enabled
-
A Boolean value which controls whether or not the audio track's sound is enabled. Setting this value to
false
mutes the track's audio. id
Read only-
A
DOMString
which uniquely identifies the track within the media. This ID can be used to locate a specific track within an audio track list by callingAudioTrackList.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
DOMString
specifying the category into which the track falls. For example, the main audio track would have akind
of"main"
. label
Read only-
A
DOMString
providing a human-readable label for the track. For example, an audio commentary track for a movie might have alabel
of"Commentary with director John Q. Public and actors John Doe and Jane Eod."
This string is empty if no label is provided. language
Read only-
A
DOMString
specifying the audio 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 an AudioTrack
for a given media element, use the element's audioTracks
property, which returns an AudioTrackList
object from which you can get the individual tracks contained in the media:
var el = document.querySelector("video");
var tracks = el.audioTracks;
You can then access the media's individual tracks using either array syntax or functions such as forEach()
.
This first example gets the first audio track on the media:
var firstTrack = tracks[0];
The next example scans through all of the media's audio tracks, enabling any that are in the user's preferred language (taken from a variable userLanguage
) and disabling any others.
tracks.forEach(function(track) {
if (track.language === userLanguage) {
track.enabled = true;
} else {
track.enabled = false;
}
});
The language
is in standard (RFC 5646) format. For US English, this would be "en-US"
, for example.
Example
See AudioTrack.label
for a simple example that shows how to get a array of track kinds and labels for a specified media element, filtered by kind.
Specifications
Specification |
---|
HTML Standard # audiotrack |
Browser compatibility
BCD tables only load in the browser