Most of our videos are made of frames from a computer screen setup dependent on a render window size. This then leaves black stripes on the top and bottom of the screen, which is ok. We now need to export some of these file in PAL DV mode (which is higher than our standard AVI format) but we need to retain the picture aspect ratio and just make up the difference in having larger black stripes top and bottom (i.e. a circle still needs to be a circle). How do we do this, to keep the width of the frames and just to make the top and bottom stripes be wider?

Albert