A feature that should be added - aspect conversion

How about adding the feature to crop a letterboxed movie formatted for a 4:3 tv to a 16:9 format movie? I have too many movies that are like this and would love to have that option for proper display on my widescreen tv. Some programs (Ahem, dr divx) will auto-crop black bars or allow manual cropping. For DVD creation, that’s not the way to go. It would have to be a static value for all 4:3 letterboxed movies regardless of the source contect (16:9, 1.85:1, or 2.35:1) so that the aspect ratio would be right. I used to know the math involved but my brain hurts now.

Isn’t that something like 720x360@4:3 pixel aspect ratio = 720x480@16:9 pixel aspect ratio??? (NTSC of course) Help me out here…

At a guess, because the video is transcoded no re-encoded this would be impossible - like conversion from NTSC to PAL…