Modifying AVI Volume Without Quality Loss

I’m obsessed with Seinfeld and I’ve been ripping every episode to AVI using x264 codec and AC3 audio. However, some seasons are louder than others and this irritates me. Is there any way to adjust the volume WITHOUT losing quality of the video or sound? I’ve used VirtualDub for things in the past but it seemed to deteriorate the audio quality. Maybe it was just me.

Anybody know whether it will or won’t, and if it does, is there anything else I can try? I’m not willing to compromise quality.

Thanks.

Nobody?

Nope!
I suppose most, just use their remotes, to lower the volume…
How did you create your avi? Does it not have some kind of normalize audio setting?..Try with avidemux…

So using VirtualDub to adjust the volume of the video will decrease its quality?