I just bought my first HD TV and would now like to hook up my xbox to do Hi Def in XBMC. I bought THIS AV pack. It has 3 connections and 1 for S-video. I assume the red and white are for audio and the yellow is for video. Do I need a component cable to hook up the video or just RCA. I assume componet, but can you buy just a single connection component cable?

the advanced av pack (which you have) will output video either by composite (yellow rca cable) or svideo (the black circular thingy) and audio either by rca (red and white) or by toslink (squarish black thing)

the hd pack will allow component video (green, blue, red) and rca audio (red and white rca's) as well as toslink

if you are wanting to use hd resolutions on your xbox you will need the hd pack as the one you have won't work