这是一个实验中的功能
此功能某些浏览器尚在开发中，请参考浏览器兼容性表格以得到在不同浏览器中适合使用的前缀。由于该功能对应的标准文档可能被重新修订，所以在未来版本的浏览器中该功能的语法和行为可能随之改变。
readyState是 MediaSource 接口的一个只读属性。它返回一个集合表明当前MediaSource的状态。它有三种可能的返回值：
closed: 当前源并未附着到一个media元素上。open: 当前源已附着到一个media元素并准备好接收SourceBuffer对象。ended: 当前源已附着到一个media元素，但流已被MediaSource.endOfStream()结束。
语法
var myReadyState = mediaSource.readyState;
值
A DOMString.
例子
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);
});
};规范
| Specification | Status | Comment |
|---|---|---|
| Media Source Extensions readyState |
Recommendation | Initial definition. |
浏览器兼容性表格
We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!
| 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) |
未实现 |
未实现 | 11 | 30 | 未实现 |
[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+.