I'm trying to reduce some AVI's files in size in VirtualDub but every time I hit "Open Video File" and I try to import a video, I get an error message usually saying something about me needed needing Xvid or some other codec. I do have DivX installed. Also I should mention that I have a x64 OS and processor and am trying out the x64 version of VirtualDub. In case your wondering, I did try reducing the size of my files in Auto GK, but I was never sure if it was working or not as it seemed to take forever for a 2 hour video file.
The author of VirtualDub responds to questions here. http://forums.virtualdub.org/index.php?s=946ce8aa4338b9ffe4a53e5a9775dac5