Changing aspect ratio of DivX avi movie

[Quimbly]

I've got a video that looks to be a DivX-encoded avi. The video looks like it was formatted for wide screen, so when I play it on my TV, I get the top and bottom horizontal bars across the screen. The funny thing is, the vid was recorded in regular 4:3 ratio, so everyone in the video looks "squashed".

I just want to re-encode/resample (/whatever) the video to full full-screen -- i.e. screen the video out, vertically.

Any suggestions?

(I'm a newb, so go easy).

EDIT: Preferrably using free tools.

EDIT: I've been experimenting with Flask MPEG, but it doesn't appear to want to open the file. Any suggestions?

EDIT: Can VirtualDub do the trick? Anyone? Please help!

[guns1inger]

What are you playing it on/with ?

[Quimbly]

Windows Media Player. Actually, I just figured out how to do it, based on the instructions here:

http://www.doom9.org/index.html?/xvid-vdub-final.htm

[celtic_druid]

You can change the AR with MPEG4Modifier. No need to re-encode, although not all players/filters will recognise the AR settings.