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 captureStream() property of the HTMLMediaElement interface returns a MediaStream object which is streaming a real-time capture of the content being rendered in the media element.
Syntax
var mediaStream = mediaElement.captureStream()
Parameters
None.
Returns
A MediaStream object which can be used as a source for audio and/or video data by other media processing code, or as a source for WebRTC.
Example
In this example, an event handler is established so that clicking a button starts capturing the contents of a media element with the ID "playback" into a MediaStream. The stream can then be used for other purposes—like a source for streaming over WebRTC, to allow sharing prerecorded videos with another person during a video call.
document.querySelector('.playAndRecord').addEventListener('click', function() {
var playbackElement = document.getElementById("playback");
var captureStream = playbackElement.captureStream();
playbackElement.play();
});
Specifications
| Specification | Status | Comment |
|---|---|---|
| Media Capture from DOM Elements The definition of 'captureStream()' in that specification. |
Editor's Draft | Initial definition. |
Browser Compatibility
| Feature | Chrome | Firefox (Gecko)[1] | Microsoft Edge | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|---|
| Basic support | 53.0 | 15 (15) -moz | ? | ? | ? | ? |
| Feature | Android | Android Webview | Firefox Mobile (Gecko) | Firefox OS | IE Mobile | Opera Mobile | Safari Mobile | Chrome for Android |
|---|---|---|---|---|---|---|---|---|
| Basic support | No support | 53.0 | ? | ? | ? | ? | ? | 53.0 |
[1] Prior to Firefox 51, you couldn't use captureStream() on a media element whose source is, itself, a MediaStream (like a <video> element which is presenting a stream being received over a RTCPeerConnection). Beginning in Firefox 51, this works. This means you can capture a stream from the video element and use MediaRecorder to record it. See bug 1259788 for details.