Convert dvd to 480x234 format (NextBase SDV97-AMB)

[qanda]This thread is about the NextBase SDV97-AMB. Click here to see full specs[/qanda]Hi there,

I have the nextbase SDV97-AM.
Now i want tot convert DVD movies to divx or Xvid format.
But when i do so i get those anoying black boxes on the top and bottom.
Does anybody know a way to get a full picture without the loss of the original film.
I use now mediacoder.