So, I have just received a 1st Gen AppleTV. I love it, but have a lot of movies I share with friends and family that dont use the iTunes format. I have installed XBMC, and its pretty good, a bit fiddly, and the music/photo functionality is sluggish.
Given that the only reason I want XBMC is to play other formats, am I better off installing a codec pack like Perian?
Once I do that, can I still stream my films that sit on an external HD on my iMac? Or would it expect me to use iTunes somehow?

Given that the only reason I want XBMC is to play other formats, am I better off installing a codec pack like Perian?
Once I do that, can I still stream my films that sit on an external HD on my iMac? Or would it expect me to use iTunes somehow?