Macbook Pro Keeps Randomly Freezing, Shutting Down, and Beeping

I had been using it for about an hour without any problems when this started happening. Ever since, I've been consistently having these issues. It is a mid 2010 model. It also sometimes flashes weird glitchy images instead of booting up or starts flashing them while I am using it, and then shuts down. Here's a quick video of what I'm talking about (it was showing even crazier images before I started recording it): http://www.youtube.com/watch?v=w-3s3MWoQB4

Any suggestions?