lossless or lossy?

I'm sorry for the OT post but I have this question and you know the answer: how can i recognize if a flac or wav file is taken from an original record like CD or is reconstructed from a lossy encoded data like mp3?thanks in advance!

These two programs are helpful (but not always 100% reliable):

For CD's/CDR's:

http://www.true-audio.com/Tau_Analyzer_-_CD_Authenticity_Detector

For FLAC/APE/etc files:

http://www.dester.hu/English/main_e.html

Hope this will help!

analfreq or EAC.

thank you!