I demand that Goga777 may or may not have written...
Your card/driver only has one Xvideo port. Some ATI card maybe?
yes ATI Radeon 9600 How is it possible to know how many xvideo ports has my card/driver ?
xvinfo. You should find one Xv adaptor, providing one overlay port, unless you're using recent xf86-video-ati, in which case you'll see another Xv adaptor, providing 16 textured video ports.
My experience of using textured video on my X300 tells me to stick to using the overlay port with that card and similar cards: the display is slightly slower, and it gets a lot slower when the video window content is composited with other windows' content. (This may not be a problem with R4xx and higher, though; I don't know.)