Maybe. There are many different codecs. Try one of these two free players (VLC and mPlayer) Both are pretty good at opening any video that can be seen on OSX. Video has been competing for years to corner the market on THE compression scheme. Anyway--here are the links:
http://www.videolan.org/vlc/download-macosx.html
http://sourceforge.net/project/showf...group_id=62947