AudioTrackList: getTrackById() method
The AudioTrackList
method
getTrackById()
returns the first
AudioTrack
object from the track list whose id
matches the specified string. This lets you find a specified track if
you know its ID string.
Syntax
js
getTrackById(id)
Parameters
id
-
A string indicating the ID of the track to locate within the track list.
Return value
An AudioTrack
object indicating the first track found within the
AudioTrackList
whose id
matches the specified string. If no
match is found, this method returns null
.
The tracks are searched in their natural order; that is, in the order defined by the media resource itself, or, if the resource doesn't define an order, the relative order in which the tracks are declared by the media resource.
Examples
This example suggests a hypothetical game in which movies are used as cut-scenes or other key set pieces within the game. Each movie has one audio track for each character, as well as one for the music, sound effects, and so forth. This function allows the game to disable a specific character's audio in order to adjust the movie's performance based on occurrences within the game; if the character's dialog isn't relevant, it gets left out. Obviously, that would require some clever graphic design to make work, but it's a hypothetical game.
js
function disableCharacter(videoElem, characterName) {
videoElem.audioTracks.getTrackById(characterName).enabled = false;
}
This short function gets the AudioTrackList
containing the video's audio
tracks using HTMLMediaElement.audioTracks
, then calls
getTrackById()
on it, specifying the character's name. The resulting
track's audio is then disabled by setting its enabled
flag to false
.
Specifications
Specification |
---|
HTML Standard # dom-audiotracklist-gettrackbyid-dev |
Browser compatibility
BCD tables only load in the browser