cvcapture Canon hacker development kit? cvcapture IP camera(direct connection)?

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I am trying to capture video on a single board pc, running opencv, under linux, with a ARM architecture. I am aware of the cvcapture functionality ie: CvCapture *camera = cvCreateFileCapture("Ip address"); How do I tune cvcapture to my special problem:

Situation 1

How do i capture video from a network camera that is connected directly to my pc? ie one end of the Ethernet cable is in the network camera, the other end is in my singleboard pc. There is no network or IP address. What code do i use ?

Situation 2

I have a canon camera with CHDK PTP(Canon Hacker Development Kit). This camera streams video to my single board pc's usb port. How do I capture video from a camera(not a webcam) in opencv, through its usb port? What code do i use ?