It does NOTHING & all it can do is just add intereferance into the image. Best to just run the HDMI stright to the tv (less to go wronge) & a toslink or analog's from the DVD or bluray player to the receiver for audio.

& if you need more HDMI ports just get a HDMI switching box, cost $28-89 depending if you want HDMI 1.3 & also how many ports.

http://www.monoprice.com/products/subdepartment.asp?c_id=101&cp_id=10110