在此页

• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

这是 实验性技术
检查 浏览器兼容性表格 要小心谨慎在生产中使用这之前。

duration 特性为 MediaSource interface gets and sets the duration of the current media being presented.

句法

mediaSource.duration = 5.5; // 5.5 seconds
var myDuration = mediaSource.duration;
					

值

A double. A value in seconds is expected.

异常

The following exceptions may be thrown when setting a new value for this property.

异常	解释
InvalidAccessError	An attempt was made to set a duration value that was negative, or NaN .
InvalidStateError	MediaSource.readyState 不等于 open , or one or more of the SourceBuffer 对象在 MediaSource.sourceBuffers are being updated (i.e. their SourceBuffer.updating 特性为 true )。

范例

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

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();
      mediaSource.duration = 120;
      video.play();
      //console.log(mediaSource.readyState); // ended
    });
    sourceBuffer.appendBuffer(buf);
  });
};
...
					

规范

规范	状态	注释
媒体源扩展 The definition of 'duration' in that specification.	推荐	初始定义。

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
duration	Chrome 23	Edge 12	Firefox 42 42 25 — 42 注意事项 Disabled 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 preference. To change preferences in Firefox, visit about:config.	IE 11	Opera 15	Safari 8	WebView Android 4.4.3	Chrome Android 25	Firefox Android 41	Opera Android 14	Safari iOS 不支持 No	Samsung Internet Android 1.5

图例

完整支持

完整支持

不支持

不支持

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

见实现注意事项。

用户必须明确启用此特征。

用户必须明确启用此特征。

另请参阅

• SourceBuffer
• SourceBufferList

元数据

• 最后修改： Dec 5, 2019

相关话题

1. Media Source Extensions API
2. MediaSource
3. 构造函数

   1. MediaSource()
4. 特性

   1. activeSourceBuffers
   2. duration
   3. readyState
   4. sourceBuffers
5. 方法

   1. addSourceBuffer()
   2. clearLiveSeekableRange()
   3. endOfStream()
   4. isTypeSupported()
   5. removeSourceBuffer()
   6. setLiveSeekableRange()
6. 继承：

   1. EventTarget
7. Related pages for Media Source Extensions

   1. HTMLVideoElement.getVideoPlaybackQuality()
   2. SourceBuffer
   3. SourceBufferList
   4. TextTrack.sourceBuffer
   5. TrackDefault
   6. TrackDefaultList
   7. URL.createObjectURL()
   8. VideoPlaybackQuality
   9. VideoTrack.sourceBuffer