I'll say it again, since you didn't bother to read what was said first time:
Even the 840av with twice the vram and at nearly double the speed of the 660av is very poor at capturing video, stock. There were, however, Nubus cards that did compression in conjunction with the DSP, and together this allowed 30fps capture in the 840av. Stock, you are limited essentially to badly stuttering video or, in effect, to capturing stills well. Performance in the 660av will be even worse, though it will do audio well.