Opening Up Mpeg movie in a medium screen

I am making an interactive video CD using Maestro menu/buttons and MPEG1 files. I'd like the MPEG1 files to open up to a medium screen size. The full screen command is too big and the MPEG1 images are very pixellated. The normal screen size is too small. Are there ways to control the screen size from the command line?

THanks alot!

-MS, New York