MediaSource: readyState property

Available in workers

The readyState read-only property of the MediaSource interface returns an enum representing the state of the current MediaSource. The three possible values are:

• closed: The source is not currently attached to a media element.
• open: The source is attached to a media element and ready to receive SourceBuffer objects.
• ended: The source is attached to a media element but the stream has been ended via a call to endOfStream().

Value

A string.

Examples

The following snippet is from an example written by Nick Desaulniers (view the full demo live, or download the source for further investigation). The function getMediaSource(), which is not defined here, returns a MediaSource.

let mediaSource;

if ("MediaSource" in window && MediaSource.isTypeSupported(mimeCodec)) {
  mediaSource = getMediaSource();
  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
  const sourceBuffer = mediaSource.addSourceBuffer(mimeCodec);
  fetchAB(assetURL, (buf) => {
    sourceBuffer.addEventListener("updateend", () => {
      mediaSource.endOfStream();
      video.play();
      console.log(mediaSource.readyState); // ended
    });
    sourceBuffer.appendBuffer(buf);
  });
}

Specifications

Browser compatibility

See also

• SourceBuffer
• SourceBufferList