I have used "DVD Audio Extractor" to extract JUST the audio from a Concert DVD.
The thing about this software is that it breaks it into multiple tracks which makes selective playback easier.
The user interface is less than ideal, but it lets you choose the output format (WAV or MP3 at various bitrates)
The tedious thing is that the database lookup to identify the DVD and the tracks themselves simply doesn't work but the subjective quality of the extraction makes fighting with the user interface worth it.
When Done I still find myself manually tagging the files and imbedding album art.
I have also used DVDfab to extract video, then used other programs to strip the audio from those files, the best results for audio with DVDfab seems to be to extract as AVI, convert to MP4 as a seperate operation then strip the audio out as mp3 using YouTube Downloader.
Tedious I know, but it gets you there...
The reason I started doing this was because of the basic reality of Concert DVD's
they have a 2hour run time.
the Companion CD has a run time of 80minutes so invariably the between song commentary by the artists to the audience is cut first, followed by any solos
often cover songs done, or songs where say the guitar tech joins them on stage...
and any "b-side" tracks that are less well known...
Because the 2hour concert must be edited to make it fit on the companion CD.
I wanted that content back.