MediaRecorder.requestData()

The MediaRecorder.requestData() method (part of the MediaRecorder API) is used to raise a dataavailable event containing a Blob object of the captured media as it was when the method was called. This can then be grabbed and manipulated as you wish.

When the requestData() method is invoked, the browser queues a task that runs the following steps:

  1. If MediaRecorder.state is not "recording", raise a DOM InvalidState error and terminate these steps. If MediaRecorder.state is "recording", continue to the next step.
  2. Raise a dataavailable event containing a Blob of the currently captured data (the Blob is available under the event's data attribute.)
  3. Create a new Blob and place subsequently captured data into it.

Syntax

MediaRecorder.requestData()

Errors

An InvalidState error is raised if the requestData() method is called while the MediaRecorder object’s MediaRecorder.state is not "recording" — the media cannot be captured if recording is not occurring.

Example

...

  captureMedia.onclick = function() {
    mediaRecorder.requestData();
    // makes snapshot available of data so far
    // ondataavailable fires, then capturing continues
    // in new Blob
  }

...

Specifications

Specification Status Comment
MediaStream Recording
The definition of 'MediaRecorder.requestData()' in that specification.
Working Draft Initial definition

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support471 ?25 ? ? ?
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support ? ? ?25 ? ? ?

1. From version 47: this feature is behind the Experimental Web Platform features preference (needs to be set to Enabled). To change preferences in Chrome, visit chrome://flags.

See also

Document Tags and Contributors

Contributors to this page: lucian95, Sheppy, jpmedley, Sebastianz, chrisdavidmills, teoli, kscarfone
Last updated by: lucian95,