November 2002

Digital Entertainment Post-Napster: Movies

Continued from page 3

By Thomas Bass

Later, I sit at Rota's elbow as he plays the famous beach scene from Apocalypse Now over and over again, each time coding and decoding the scene by a different method. He is testing improvements for the next release of his software, evaluating the pixels in every scene frame-by-frame to see how good they look, using a kitbag of psychovisual tools to get the edges crisp. "There are many tweaks involved in increasing compression. We can make you think in your mind that one image is the same as another, even when it holds a lot less information," he says.

 "A DVD is a 100-to-1 compression of the original film. A DivX video is a 10-to-1 compression of a DVD. By the end, you are dealing with an image that might have a thousand times less information than the original," Rota explains. The key is to pick the information that is most important for the viewer and allocate resources accordingly. Rota's tricks include pulling bits out of the background or reducing 50 shades of black to one, using the saved memory for better results such as highlighting people's faces. "Only recently have we had the kind of computer power that allows us to put psychovisual tools into our video compressions," he says. "Video compression used to be a mathematical problem. Then it turned into a medical problem. Now I read a lot of papers by scientists on the human visual system."

It is seven o'clock in the evening, and the room is filled with the screams of players being killed in an online video game called Unreal Tournament. Outfitted with headphones and pounding furiously on their keyboards, the company's employees, their Herman Miller chairs turned into personal military-command centers, are trying not to get wasted by the fearsome firepower of their enemies. Rota is good, really good, at weaving and ducking his way out of one tight scrape after another. Armed with a sniper rifle, he shoots madly, rushing to capture the flag that is out there somewhere.