Web/API/MediaSource/addSourceBuffer

The addSourceBuffer() method of the MediaSource interface creates a new SourceBuffer of the given MIME type and adds it to the MediaSource's sourceBuffers list. The new SourceBuffer is also returned.

Syntax

var sourceBuffer = mediaSource.addSourceBuffer(mimeType);

Parameters

mimeType: A DOMString specifying the MIME type of the SourceBuffer to create and add to the MediaSource.

Return value

A SourceBuffer object representing the new source buffer that has been created and added to the media source.

Exceptions

InvalidAccessError: The value specified for mimeType is an empty string rather than a valid MIME type.
InvalidStateError: The MediaSource is not in the "open" readyState.
NotSupportedError: The specified mimeType isn't supported by the user agent, or is not compatible with the MIME types of other SourceBuffer objects that are already included in the media source's sourceBuffers list.
QuotaExceededError: The user agent can't handle any more SourceBuffer objects, or creating a new SourceBuffer using the given mimeType would result in an unsupported configuration of SourceBuffers.

Example

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

var assetURL = 'frag_bunny.mp4';
// Need to be specific for Blink regarding codecs
// ./mp4info frag_bunny.mp4 | grep Codec
var mimeCodec = 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"';

if ('MediaSource' in window && MediaSource.isTypeSupported(mimeCodec)) {
  var mediaSource = new MediaSource;
  //console.log(mediaSource.readyState); // closed
  video.src = URL.createObjectURL(mediaSource);
  mediaSource.addEventListener('sourceopen', sourceOpen);
} else {
  console.error('Unsupported MIME type or codec: ', mimeCodec);
}

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();
      video.play();
      //console.log(mediaSource.readyState); // ended
    });
    sourceBuffer.appendBuffer(buf);
  });
};

Specifications

Specification	Status	Comment
Media Source ExtensionsThe definition of 'addSourceBuffer()' in that specification.	Recommendation	Initial definition.

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
`addSourceBuffer` Experimental'	Chrome Full support 23	Edge Full support 12	Firefox Full support 42 Full support 42 No support 25 — 42 Notes' Disabled' Notes' Limited support to an allowed list of sites, for example YouTube, Netflix, and other popular streaming sites. The limitation 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 15	Safari Full support 8	WebView Android Full support 4.4.3	Chrome Android Full support 25	Firefox Android Full support 41	Opera Android Full support 14	Safari iOS No support No	Samsung Internet Android Full support 1.5

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.