Here's the problem, I have a couple of bootlegs in two versions: 128k & 192k and I'm trying to figure out which one has the better quality. I have reasons to believe that the source was only in 128k so that means the 192k ones must have been re-encoded from 128k. Is there any way to tell for sure whether the 192k are re-encoded?

This has been asked a million times here -

http://www.hydrogenaudio.org/forums/index....t=0&#entry65553

that should help though .

There's no way to tell for sure, but the best way is to conduct a blind listening test on both files and see which one you perceive as being the best quality. To do this you'll need a tool such as ABChr (do a search if you want to know more about that).

Edit: Heh, someone beat me to it..