You boys are all way off here, you don't need nuthin' to record from a DVD, just put it in your computer and use a DVD audio ripping application. Just google for DVD audio ripper, choose your platform and that's it. You can preview the film to the point you need, then extract the audio as a .wav, .aiff or .mp3 (plus loads of others like SD2 etc) for the duration you need it.
It's simple and quick and gives you 100% digital quality, exactly as you hear it on the original.
To record from TV, as others have said, get a tuner card/usb device for your computer and record directly in, or if not, buy a SCART box (really cheap) with RCA connectors and go from there to your sound in. The audio goes from the TV to the SCART box, then to your computer via the RCA plugs. Easy. Not 100% but not far off.
If you need specific apps for Mac or PC let me know. If you actually want them, PM me to discuss...