Flovie, I was talking to a coworker about a similar concept on the way back from a tech conference this past Friday. I agree with most of your pros/cons. Since I'm not familiar with the "proto" approach, I'd think I'm going to explore this V4L2 virtual camera in combination concept with the OpenCV fisheye undistort. I'm completely unsure of the performance impacts to the video stream. I'll play a bit with it, but I haven't purchased a true fisheye lens camera yet. Regarding "proto", are you talking about protocol buffer? Can you provide a hyperlink please?