It's pretty hard to do reliably and at speed. With an old Riva TNT2 video card I could grab from the screen a window 640x480 at 30fps and 32 bit colour with CamStudio 1.2, but since I got a 'better' ATI Radeon 9000 Pro I can just barely manage 15fps of 180x120 with 16 bit colour. Sure, my frame rate on Quake 3 Arena went way up, but I lost fast screen grabbing. It's got to be the ATI drivers doing the dirty work, but there's no alternative. I think I'll dig out the old parts and put together a slower machine that can grab screen video fast. This may be one of those times older is better.
Fav quote - "Experience is whatcha don't get 'till ya don't need it no more."
System - Athlon 1.4GHz, Win98, Hauppauge PVR250 receiver and compressor.
Software -Magix Movie Edit Pro 10, Nero 6 + NeroVision Express, Moho 4.61, PSP 8.1, Bryce, Quicktime 6.52 pro, Goldwave 5, DVD-Lab.
Cameras - Panasonic GS9, Canon ES8400V, Canon EOS D20 and Canon A70