video to texture without passing through AGP bus

I’ve been looking for a good solution for going from video to texture. There are some posts on these forums on this subject, but they all seem to refer to subloading frames from system RAM to the texture memory on the graphics card.

Does anyone know of a solution where data from the video-in on a graphics card can be dumped straight to texture memory? It seems like the biggest bottleneck with using video as texture is sending the frames to the graphics card. This would be necessary when using a seperate video capture card, but many graphics cards seem to have video-in on them these days.

While I’m posting this, does anyone know how to do this all digitally? I believe digital video is higher quality than composite or s-video. Are there any graphics cards with any kind of digital input ports? Or is using a firewire card the only way to get DV into your computer?