Compressing AUDIO from VOB file

[ijuf]

i was wondering if there's anyone who can help me how to make the audio size smaller so when using like "DVD Shrink" for example, i wouldn't have to shrink the VIDEO. DVD Shrink can only shrink the VIDEO and NOT THE AUDIO.
there are 5 VOBs total, and the AUDIO is LPCM-2 channel(1536K).
is there a good tool that extracts AUDIO file from the VOBs? i don't want to touch the VIDEO, only compress the audio. I've read some posts about using TMPgenc, but it seems that it only works with MPG files, and not VOBs. sorry if i'm wrong.
if it's impossible to do this, is there other way of doing something similar to this? i would really appreciate it if i can get some help.

[flaninacupboard]

when ripping the DVD in DVDdecrypter ask it to demux the Audio and video. you will now have a .m2v video file and a .wav audio file.

[wulf109]

If the files are already on your HD,VOBEDIT can demultiplex them into m2v and PCM. Convert the PCM audio to mpa. You will need to author into a DVD VIDEO_TS directory so you then use DVD Shrink.

[ijuf]

thank you so much to both who helped me.
question to flaninacupboard:
if i use dvddecryptor and demux the Audio and video, what tool do i use to remux it back together? and do you know a good program to edit the wav file?

question to wulf109:
how do i convert the LPCM audio to mpa by using VobEdit? i'm kind of new to this, so could you tell me which one i should do after clicking demux? there are 2 options. do i select "Demux" for video and audio one by one, or "demux multiple streams at once" and checking both "demux all video and audio streams?" and do you know a good program to edit the audio file?
Again, thanks for getting me started.