If you installed a virtual webcam and integrated webcam alre

Question

I am working on automatically find which webcam is working properly on my machine.

Condition:

1) If you have two webcam one working and another one is not working. And the not working is in 0th position so is comes first so code taking 0th position. 

2) If you installed a virtual webcam and integrated webcam already present so how to identify that which is a virtual or working webcam.