MediaSource.activeSourceBuffers

The activeSourceBuffers read-only property of the MediaSource interface returns a SourceBufferList object containing a subset of the SourceBuffer objects contained within sourceBuffers — the list of objects providing the selected video track, enabled audio tracks, and shown/hidden text tracks.

Syntax

var myActiveSourceBuffers = mediaSource.activeSourceBuffers;

Value

A SourceBufferList containing the SourceBuffer objects for each of the active tracks.

Example

The following snippet is based on a simple example written by Nick Desaulniers (view the full demo live, or download the source for further investigation.)

function sourceOpen (_) {
  //console.log(this.readyState); // open
  var mediaSource = this;
  var sourceBuffer = mediaSource.addSourceBuffer(mimeCodec);
  fetchAB(assetURL, function (buf) {
    sourceBuffer.addEventListener('updateend', function (_) {
      mediaSource.endOfStream();
      console.log(mediaSource.activeSourceBuffers);
      // will contain the source buffer that was added above,
      // as it is selected for playing in the video player
      video.play();
      //console.log(mediaSource.readyState); // ended
    });
    sourceBuffer.appendBuffer(buf);
  });
};

...

Specifications

Specification Status Comment
Media Source Extensions
The definition of 'activeSourceBuffers' in that specification.
Recommendation Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic support
Experimental
Chrome Full support 31
Full support 31
No support 23 — 31
Prefixed
Prefixed Implemented with the vendor prefix: -webkit-
Edge Full support 12Firefox Full support 42
Full support 42
No support 25 — 42
Notes Disabled
Notes Limited support to a whitelist of sites, for example YouTube, Netflix, and other popular streaming sites. The whitelist was removed when Media Source Extensions was enabled by default in Firefox 42.
Disabled From version 25 until version 42 (exclusive): this feature is behind the media.mediasource.enabled preference. To change preferences in Firefox, visit about:config.
IE Full support 11
Notes
Full support 11
Notes
Notes Only works on Windows 8+.
Opera Full support 15Safari Full support 8WebView Android Full support 4.4.3Chrome Android Full support 33Edge Mobile Full support YesFirefox Android Full support 41Opera Android Full support 30Safari iOS No support NoSamsung Internet Android Full support Yes

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.
See implementation notes.
See implementation notes.
User must explicitly enable this feature.
User must explicitly enable this feature.
Requires a vendor prefix or different name for use.
Requires a vendor prefix or different name for use.

See also

Document Tags and Contributors

Contributors to this page: Sheppy, fscholz, libbymc, chrisdavidmills
Last updated by: Sheppy,