Need Video-In Capture Software

I have an Asus 6600 Deluxe Geforce 256 with S-Video In. I plan on getting a Gamecube very soon(re-release of Resident Evil wewt!), and want to use my S-Video in to play. Now, I previously owned a PS2, and used it with the S-Video in. But, the only software I could find that actually displayed the picture being sent in to the video card was a program that came with the Asus drivers. I have yet to find a stand-alone program that captures video-in. I don't want to use the Asus drivers because they are buggy, slow, and look like crap. Does nVidia make thier own software? Any suggestions at all would be appreciated.