Software to convert a letterboxed video back to true widescreen?

[gastrof]

I have a piece of video downloaded from YouTube that's was converted from widescreen to letterboxed 4x3. It's sort of a companion piece to some other videos that are in real widescreen.

I'd like to have all of them in true widescreen format, but I don't know of any way to change the letterboxed one into true 16x9 (more or less chopping off the black bars at the top and bottom).

Is there any software that can achieve that? I'd prefer freeware, but any information would be welcome.

Thanks.

[guns1inger]

virtualdub with the flv plugin, or AVIDemux. Both are free. You will have to re-encode.

[gastrof]

Thank you, but I'm still a bit lost. (Still very much a newbie with these things.)

I didn't know where to find or how to install the flv plugin for virtualdub, so I tried downloading AVIDemux.

I've figured out how to crop the black bars out, and make the video true widescreen, but I'm lost on how to resave it in the new aspect ratio.

I don't know what video, audio, and format settings to use on the AVIDemux controls. If I leave it at "copy", even with the video filters set to crop it saves the video as it was, with the black bars and all. No cropping takes place.

Seems "copy" is not the setting to use, but I don't know what settings SHOULD be used.

(As a side point, is there a way to use AVIDemux to lower the volume a bit?)