Okay so I got an 11.6" macbook air yesterday, and it doesn't have a disk drive. I will be going on holiday in about a week, and the plane ride will be 7 hours, so I want to put my Modern Family Season 2 box set onto my macbook to watch on the plane, but my mac doesn't have a disc drive. So I put the dvd onto a usb and put all the files onto my desktop. However, they won't play, and when I try to play them it comes up with this notification:
QuickTime Player can't open "Modern Family S2 EP01-06.avi" because a required codec isn't available.

I downloaded the codec thingy, and it says to put it into the 'quicktime player libraries" or something.
What is the quicktime libraries? How do I get to it?

Or is there any other way I can get quicktime player to play the files?
Thanks.