VLC Player should be able to handle it.
What do I need to open an "mp4?" A friend gave us a "SanDisk" (from a pc) with wedding video and when I try to play it, I get the message, "you cannot open the application Kodak EasyShare because it may be damaged or incomplete." The still photos that are on the same disk are OK. Dang.......... Thanks,
Old Granny Lola