That's really neat Jason, what with all the 'assembly is dead' stuff that gets bandied around it's nice to see people keeping the art alive and collaborating at this level.
Find a video (en|de)coder without SIMD and you've found an unusable piece of software.
There's a reason that Intel focuses so much on SIMD instructions and arithmetic units with each new chip release: if not for SIMD or dedicated hardware, it would be physically impossible to decode 1080p video on almost any modern machine.
It's posts like these that can help getting the 70's stigma that assembler seems to be associated with removed.
Someone ought to do a major article about assembler in todays IT environment. Who does it, why they do it and why it is relevant.
Also worth noting that these video decoders tend to crash hard on invalid input. Tradeoffs.