RDK X3: How to change from MIPI to USB for camera selection

Hello!

One of the RDK X3 samples for real-time object detection uses the following code snippet for the MIPI CSI camera:

cam = srcampy.Camera()
cam.open_cam(0, -1, fps, [512, 1920], [512, 1080])
enc = srcampy.Encoder()
enc.encode(0, 3, 1920, 1080)

What changes need to be made to use any valid USB camera (that has been tested successfully with other samples)? Thanks.

Regards.