[LAU] Soundtrack from recorded TV

Hi all, I recorded this fabulous movie from the 1920s, "Faust" by German filmmaker Murnau, as it was shown on TV. It has a fabulous soundtrack which is akin to bands like Univers Zero and Art Zoyd but in a lighter mood so to speak. Even perhaps an enriched version of The Residents. In short, it's a good listen and a good inspiration for meldoci and rythmic moods. Moreover, according to IMDB it seems there are several soundtracks, so it could be unlikely for me to rent the exact same DVD. I could load the recorded track into Kino and save only the audio (I guess - I never did it yet) but that takes an awful lot of time because Kino will have to convert the file and the movie last about two hours, so that's a lot of processing time. My question is, is there an utility out there that will separate the audio from the images of a recorded track and record the audio in a separate track (possibly at a higher speed than regular viewing) ? Thanks for any suggestions, Al