Not sure, I would be very surprised if mplayer can't do it. I never really used kmplayer, I simply ran mplayer from command line.

You might want to start a new thread about video playback, to keep the topic clean, but don't forget to search the forums properly first! People here are really happy to help others out, but only if the asker is prepared to put in some work themselves too (by checking that the answer isn't already answered first).