Making video fullscreen without scaling interface controls

Sites like http://www.thedailyshow.com/ are doing what I need to do. When you go fullscreen with their video, the bottom video controls and the top social media bar aren’t scaled. They adjust themselves in width, but the text and button graphics remain the same size.

I’ve had success with a method where, when the FULLSCREEN event is invoked, I downsize my interface elements by a ratio equal to the difference between my SWF size and the screen size, essentially keeping the interface at a constant size in both modes. However, all text and graphics inside those elements are distorted or blurred when I do this. At http://www.thedailyshow.com/, the text looks exactly the same in both modes, and uses no anti-alias.

How do they do this?