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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 HTMLCanvasElement.captureStream() method returns a CanvasCaptureMediaStream that is a real-time video capture of the surface of the canvas.
Syntax
MediaStream = canvas.captureStream(framerate);
Parameters
- framerate Optional
- A
doublethat indicates the rate of capture of each frame. If not set, a new frame will be captured each time the canvas changes; if set to0, one single frame will be captured.
Return Value
A reference to a MediaStream object.
Example
// Find the canvas element to capture
var canvasElt = document.querySelector("canvas");
// Get the stream
var stream = canvasElt.captureStream(25); // 25 FPS
// Do things to the stream
// E.g. Send it to another computer using an RTCPeerConnection
// pc is an RTCPeerConnection created elsewhere
pc.addStream(stream);
Specifications
| Specification | Status | Comment |
|---|---|---|
| Media Capture from DOM Elements The definition of 'HTMLCanvasElement.captureStream()' in that specification. |
Editor's Draft | Initial definition |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 51.0 | 43 (43) [1] | No support | 36.0 | ? |
| Feature | Android | Android Webview | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|
| Basic support | No support | 51.0 | 51.0 | 43.0 (43) | No support | 38 | ? |
[1] In Firefox 41 and 42, this feature was disabled by default; set the preference canvas.capturestream.enabled to true to activate.
See also
CanvasCaptureMediaStream, the interface it belongs to.