> Open the DVD from the drive in Avidemux, as if to Copy or Convert.
> Once opened, check the type of Audio - AC3, AAC, PCM, etc - by clicking the Blue "i" button on the bar. Then go to Audio on the bar, and click 4th down, "Save".
> In the window that opens, path and name the audio - "mymovie.ac3", etc, using the audio type extension.
> Save the Audio to desired Destination.
> Convert it to FLAC or WAV.
> Open in Audacity, find the part(s) you want, Select each, and File > Export Selection.
> In the dialog that appears, choose desired format and quality level, name the File with that extension...
> Export to desired Destination.
> Wherever it's legal to do so - Opening in Avidemux and Saving Audio is a good way to extract the Audio from Y'Tube and similar videos. Choose the "Large" FLV (actually often now H264) - or MP4s. The Audio is often AAC-etc, not MP3.
> Convert the AAC-etc as above.
> To Trim the Starts and Finishes - open in Audacity and Select the Desired Audio.
> To get lead-in and lead-out, trim a bit wider, then Select X-seconds of lead-in. Select "Fade-In" on the Effects Menu, and set the audio-slope you need. For lead-out, use "Fade-Out" on Effects Menu.
> When trial-play shows the functions required, Select from beginning of lead-in to end of fade-out - and Export Selection in the format and quality preferred.