Oh, Tony, while watching a lyric scroll by, I had an epiphany about the CPU usage with the burnin feature.

Are you recalculating the burnin pixels for every frame?

The text doesn't change nearly as many times per second as the visual does. If the burnin pixels and/or text were somehow stored in a third buffer (perhaps using an intermediate pixel value as the value for transparancy), and just the buffer-overlay-onto-background operation happened every frame, then you'd only need to rewrite the buffer when the foreground layer changed (say, when the user presses a button, or when the time index counter rolls over and you draw a time, etc.).

This means the burnin code would eat a lot less CPU. It would still make a stutter when it *did* run, it just wouldn't happen every frame any more.