The difference between jpg & jpeg is "e"!!!

ie: there's no difference. But keep in mind it's an image format, not a video format.

If you want to watch multiple video formats with the one player then get VLC - (click on link) _ (choose nearest mirror site) as it has in-built codecs & is generally very reliable. To see what it can play see http://www.videolan.org/vlc/features.html