It's nice to see you drivers, but why did they decide you need a TV-tuner as well ?
Implementations I've seen on "other" platforms transfers the data across the PCI bus directly to the video board, wonder why they chose this way ?
Thinking about it I did pretty much what they are doing now using a Vela board a couple of years ago, probably wasn't as reliable (as I did the software) but it did have SDI output :-)