software that supports 2 time lines

[kcb]

I currently use adobe audition to chop some stuff out of an mp3 and re-mux it back with xvid video. The problem with this method is adobe auditon re-encodes the whole thing (which is bad!) and it doesn't use a good mp3 encoder (LAME). I can't just feed the mp3 to gknot and "mux" it because i have to do some post-processing on it. The video part is no problem because i use virtualdub mod and set the video to direct stream copy which in the end isn't reencoded.

So i was wondering if there were alternatives that support 2 time lines where i can compare a track to another, chop some bits and export it without re-encoding it. I don't need the software to support LAME (the whole point is NOT to re-encode it) since the mp3 i'm using is already encoded with LAME, i just want to export the cut/chopped version untouched.

Thanks alot.