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.

Returns

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 Extensions
The definition of 'addSourceBuffer()' in that specification.
Recommendation Initial definition.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support

31

23 — 31 -webkit-

12

42

25 — 421 2

113158
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support3333 Yes4130 No Yes

1. 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.

2. From version 25 until version 42 (exclusive): this feature is behind the media.mediasource.enabled preference. To change preferences in Firefox, visit about:config.

3. Only works on Windows 8+.

See also

Document Tags and Contributors

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