as long as you dont have it set to full screen it doesn't. You can just stretch it as big as you want, take the screenshot, edit out everything but the film still, and voila. And if you want, you can even use photoshop (if you dont have it send me the still frame, check the lil buttons for my contact info), and ill make it %125 bigger. Since photoshop has that making photos %125 bigger without quality loss.
EDIT: nevermind, when ever i try to edit it it gets messed up. how do you delete threads?