Enhancing AVI Files

[moviebuff2]

A friend of mine sent me an AVI file (a homemade one, of course) which:

1) displays the bright light sections fine, but

2) displays poorly sections that are in dark colors. Instead of showing a solid dark color, the section looks as if it was made up by multiple pixels of different shades of that dark color.

What can I do to enhance it?

Also, which software can I use to get still pictures from an AVI file. I tried Virtual Dub and it did not play the file. VLC plays the file but does not have any function to get still frames.

Thanks

[Baldrick]

what is the video codec? identify with gspot,avicodec,etc

[moviebuff2]

gspot says:

4CC DX50/divx

Name DivX 5.0