Rotating video with mencoder

This is something that has been bugging me ever since I got a digital camera that could do video – how do you rotate a “portrait” video back to “landscape”. Recently a friend asked me to do this for something important – a video she took for “The children’s wish foundation” so I looked a little more. I finaly found how to do it with mencoder at Scott Hanselman’s site.

He even goes into describing the flags for the tool – which is always good. As well, to make things cleaner, how to get the aspect ratio back to 4:3. I now have a few videos to rotate.