Problems with avi playback

The past couple of days I've been having some problems playing some of my .avi files. Any movements on screen seem to be a bit faster than normal. The audio syncs up with the video fine, but any movement the character make like walking/moving their arms or when the camera pans is a little jerky and fast. It's not unwatchable, just enough to be annoying. It's happening with .avi files that have previously been fine as well as new ones. I've tried opening the files using quick look, quicktime and vlc and I'm getting the same result with them all.

Can anyone help me with this problem?