This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.
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 receiveSourceBuffer
objects.ended
: The source is attached to a media element but the stream has been ended via a call toMediaSource.endOfStream()
.
Syntax
var myReadyState = mediaSource.readyState;
Value
A DOMString
.
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.)
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 'readyState' in that specification. |
Candidate Recommendation | Initial definition. |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 23 | (Yes) | 25.0 (25.0)[1] 42.0 (42.0) |
11[2] | 15 | 8 |
Feature | Android | Edge | Firefox Mobile (Gecko) | Firefox OS (Gecko) | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | 4.4.4 | (Yes) |
No support |
No support | 11 | 30 | No support |
[1] Available after switching the about:config
preference media.mediasource.enabled
to true
. In addition, support was limited to a whitelist of sites, for example YouTube, Netflix, and other popular streaming sites. The whitelist was removed and Media Source Extensions was enabled by default in 42+ for all sites.
[2] Only works on Windows 8+.