Web/API/AudioTrackList/getTrackById

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

var theTrack = AudioTrackList.getTrackById(id);

Paramters

id: A DOMString 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.

Example

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.

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	Status	Comment
HTML Living StandardThe definition of 'AudioTrackList.getTrackById()' in that specification.	Living Standard
HTML5The definition of 'AudioTrackList.getTrackById()' in that specification.	Recommendation

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`getTrackById`	Chrome Full support 37 Disabled' Full support 37 Disabled' Disabled' From version 37: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`). To change preferences in Chrome, visit chrome://flags.	Edge Full support 79 Disabled' Full support 79 Disabled' Disabled' From version 79: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`). No support 12 — 79	Firefox Full support 33 Disabled' Full support 33 Disabled' Disabled' From version 33: this feature is behind the `media.track.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE Full support 10	Opera Full support 24 Disabled' Full support 24 Disabled' Disabled' From version 24: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`).	Safari Full support 6.1	WebView Android No support No	Chrome Android Full support 37 Disabled' Full support 37 Disabled' Disabled' From version 37: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`). To change preferences in Chrome, visit chrome://flags.	Firefox Android Full support 33 Disabled' Full support 33 Disabled' Disabled' From version 33: this feature is behind the `media.track.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	Opera Android Full support 24 Disabled' Full support 24 Disabled' Disabled' From version 24: this feature is behind the `enable-experimental-web-platform-features` preference (needs to be set to `enabled`).	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.

AudioTrackList.getTrackById() by Mozilla Contributors is licensed under CC-BY-SA 2.5.