I must warn you that I have an earlier version of easycap and it is crap. If you are going to use an usb capture device get the best you can afford. You need a fairly fast processor in your computer to use them full screen in HD.
Thank you for your helpful input rojash. I explained at least one way to do what the OP wants to do.
Your "You can't explain problems very well, either." or "Do you expect us to read your mind?" is ofcourse a lot more helpful. To me it is just plain rude, especially to a brand new member. Not everyone is computer savvy.