voltmx.screenrecorder Namespace
The voltmx.screenrecorder namespace, helps you to implement the screen record feature of WebRTC in your web apps.
You can use the functions available in the voltmx.screenrecorder namespace to start, pause, resume, and stop the screen recording. To know the current state of the recording, use the getrecordedstate API. After the screen recording has been completed, use the getrecordeddata API to fetch the video as a Blob URL.
The APIs in voltmx.screenrecorder namespace are applicable only for the Desktop Web platform.
Note: This feature is currently supported only in Google Chrome ( v72 and later) , Mozilla Firefox( v66 ) and Opera(v60).
Functions
The voltmx.screenrecorder namespace contains the following functions.
voltmx.screenrecorder.start
You can use the start API to initiate the recording of the screen. When this method is invoked, the web browser asks for permission to select the window, tab, or screen.
Syntax
Parameters
config
The config parameter consists of a JavaScript object. It contains the following attributes.
Attributes | Description |
---|---|
framerate | Framerate is the number of consecutive images/ frames that appears on a screen per second. The default value is 30fps. This is an optional parameter. |
onFailure | onFailure contains the callback that is invoked when an error occurs while recording, For example, this callback is invoked when the web browser does not support the screen recording feature. This is an optional parameter. |
The callback for the onFailure
key must have the following signature.
onFailureCallback(err);
here, the err
parameter is a string that contains the reason for the failure.
Example
Return Values
None
voltmx.screenrecorder.pause
You can use the pause API to temporarily stop the recording of the screen. You can restart the recording process by using the resume API.
Syntax
Parameters
None
Example
Return Values
None
voltmx.screenrecorder.resume
You can use the resume API to restart the screen recording after the pause API has been invoked.
Syntax
Parameters
None
Example
Return Values
None
voltmx.screenrecorder.stop
You can use the stop API to end the screen recording. After the recording process is stopped, you can use the getrecordeddata API to retrieve the Blob URL of the video.
Syntax
Parameters
None
Example
Return Values
None
Remarks
- After you have invoked the stop API, invoke the getrecordeddata API to retrieve the screen recording. If you invoke the start API before invoking the getrecordeddata API, the new recording overrides the previous recording. The previous recording is not retained and you will lose the data.
voltmx.screenrecorder.getrecordeddata
You can use the getrecordeddata API to retrieve the screen recording in the form of a Blob URL.
Syntax
Parameters
None
Example
Return Values
Returns a Blob URL of the screen recording as a String.
Note: In the Opera(v60) web browser, if you assign the Blob URL of the screen recording to the source property of the Video widget, the recording may not start. This is because the Opera(v60) web browser has a technical limitation while playing an HTML5 video.
voltmx.screenrecorder.getrecordedstate
You can use the getrecordedstate API to retrieve the current state of the screen recording.
Syntax
Parameters
None
Example
Return Values
This API can return any one of the following values.
State | Description |
---|---|
inactive | The screen recording has not started or it has been stopped. |
paused | The screen recording has been paused. |
recording | The screen is being recorded. |