mplayer flip does mirror, not rotate
 

In the man pages of mplayer I find an example that tells me, if I really want to watch the video upside down (German man says "Handstand", which is what I want to do), I should use "-flip=yes", but this is wrong: The video is then mirrored on the x axis and you cannot read the text on the screen. Other options like "mirror" or "rotate" do not seem to work for me. I want the image rotated 180 degrees. Regards, Horst.

You need to use both "flip" and "mirror" together to get the effect of a 180 degree rotation.