I have a bunch of various videos that I want to convert in a good format to play on my mp3/video player. The videos are of different formats and different resolutions.

My player has a screen resolution of 320x240 pixels so I want to tell MEncoder to resize files so that the width an height don't exceed the screen resolution. Still I wish to keep the aspect ratio of the movies and I don't wish to scale any videos up to fit the screen.

Is there a simple way to do this?