reauthor OR reencode DVD files to get volume boost?

I am wondering if there's any easy way to boost the volume on an already-authored DVD of stuff taken from VHS tapes...

I have TMPGEnc express and dvd author. Any help much appreciated, I hate to hand out dvds that need like a whole turn of the knob on the stereo amp to be heard at a proper volume.

 

Demux the audio from the file produced by tmpgenc xpress.
Load into Goldwave.
Select Effect, Volume, Double.
Save it as .wav
Re-encode that .wav in tmpgenc to mp2.
Remux with the video.
Author.
You can also try tmpgenc's volume increase/normalize during the original encode, but this can add a lot of time to the encoding.

 

erm, actually I need to do this with the VOB's not an mpg...
but thanks.

 

Rip the mpeg from the vobs. ReJig will do it (to elementary streams, which is what you need anyhow), then increase volume, and reauthor.