I don't have any info posted about the camera setup, but we're using a Windows laptop with some random QR reader (fastest one we found) to call the unlock URL on the Linux lock server sitting next to it w/the key from the QR code.

Here's a brief post I did on the lock system itself: http://adrianpike.tumblr.com/post/6009384439/door-locks-on-r...

Source is over on GH, but it would be pretty straightforward to roll your own nice & quick. If you do want to use mine, I'd be totally willing to help hack in new features, I've got lots of stuff I want to improve it with, but just don't have the side project time.