How to Convert 640x480 source for PSP TV-OUT

Hello

I have a DVDFab created VOB file with a resolution of 640x480. I want to Convert this file to playback on my PSP and PSP TV-OUT.
The PSP with the current firmware supports 640x480 resolution or a 640x480 file with bars on the side so its actually 720x480. Black bars are fine with me.
But neither are an option with Converting for the PSP it seems. For PSP tv-out all i get is 720x480 and the video gets stretched.
Is there something i can do?

Thanks

Looking around I just found the profile editor. Will test the options I want with a new profile.