Web/API/MediaSession/setPositionState

The MediaSession method setPositionState() is used to update the current document's media playback position and speed for presentation by user's device in any kind of interface that provides details about ongoing media. This can be particularly useful if your code implements a player for type of media not directly supported by the browser.

Call this method on the navigator object's mediaSession object.

Syntax

navigator.mediaSession.setPositionState(stateDict);

Parameters

stateDict Optional: An object conforming to the MediaPositionState dictionary, providing updated information about the playback position and speed of the document's ongoing media. If the object is empty, the existing playback state information is cleared.

Return value

undefined.

Exceptions

TypeError: This error can occur in an array of circumstances:

The specified MediaPositionState object's duration is missing, negative, or null. position is missing or null, or is either negative or greater than duration. The playbackRate is zero.

Example

Below is a function which updates the position state of the current MediaSession track.

function updatePositionState() {
  navigator.mediaSession.setPositionState({
    duration: audioEl.duration,
    playbackRate: audioEl.playbackRate,
    position: audioEl.currentTime
  });
}

We can use this function when updating media session metadata and within callbacks for actions, such as below.

navigator.mediaSession.setActionHandler('seekbackward', details => {

  // our time to skip
  const skipTime = details.seekOffset || 10;

  // set our position
  audioEl.currentTime = Math.max(audioEl.currentTime - skipTime, 0);
  updatePositionState();

});

Specifications

Specification	Status	Comment
Media Session StandardThe definition of 'MediaSession.setPositionState()' in that specification.	Draft	Initial definition.

Browser compatibility

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

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
`setPositionState()` Experimental'	Chrome Full support 73	Edge Full support ≤79	Firefox Full support 76 Disabled' Full support 76 Disabled' Disabled' From version 76: this feature is behind the `dom.media.mediasession.enabled` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE No support No	Opera Full support Yes	Safari No support No	WebView Android No support No	Chrome Android Full support 57	Firefox Android No support No	Opera Android No support No	Safari iOS No support No	Samsung Internet Android Full support 7.0

Legend

Full support: Full support
No support: No support
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.
User must explicitly enable this feature.': User must explicitly enable this feature.

MediaSession.setPositionState() by Mozilla Contributors is licensed under CC-BY-SA 2.5.