There is an example very similar to your requirements in our SDK repository. You can either navigate to the Rad Upload Integration demo with the SDK Samples Browser
or browse the code directly in GitHub
As to taking a capture, you can try using the GetAvailableVideoCaptureDevices()
method to obtain the device and call the Start() method of the capture source. Note that due to Silverlight's security policy you'd need to request access from the user first.
I hope this helps.
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