A gap year doesn't necessarily have to be something related to your intended major or career. You can work, travel, take a few classes at the community college to explore a subject just for fun, do some community service at a charity you really believe in. Or if you really want to delve into film, you can do some reading on your own, and watch a lot of films to immerse yourself in how the pros do it. It's a year for growing up, so don't put pressure on yourself to "achieve" something. Have fun and relax. You'll be refreshed and ready to go when you get to college.