Does anyone here know of a good HD video capture card that has a good (comprehensive) API? I administer a few servers that do some video encoding right now, but when we make the switch to HD cameras, they won't be sufficient.

In addition to this, the servers we have now are black boxes, closed to me except to start/stop the video capture device. I'd like to be able to roll my own, so we can better integrate it with our existing systems, but I know almost nothing about what kind of HD capture cards are out there, and if I can avoid spending money just to test their APIs that would rock.

So does anyone have any experience with this? All our other software is in C#, and I'd like to set up the new servers with web interfaces to start/stop the capture (also in C#, using .NET 3.5 probably). I'm not sure how language specific these APIs would be, but that's what I'm working with just as a reference point. I appreciate any help the community can give!