interactiv with webcam

hallo everyone,

its my first time to try ghowl, and I have problem to start it, in case how to 'plug-in' my device: a webcam.

I opened the sample file 'gHowl_UDP_receive_Cam.ghx'. It says the sample file will  associated Processing sketch: gHowl_UDP_receive_CAM.pde...

what it that mean? and what is a *.pde file?

I assuming this sample file will aim to interactive with a webcam...seems UDP receiver accept only the IP address as input...How can I connect my webcam as input? I am mean find out its IP, PORT, Pattern (999?)...etc...?

It would be very helpful for me if anyone knows any kind of step by step tutorial for the beginner?