Is there some software that will analyze a flac file or a wav file and be able to determine whether the file was at some point processed by a lossy encoder?

In other words, I want to find out whether a given flac file was encoded directly from a CD, or whether it was perhaps encoded to ogg, then at some point decoded back to wav and then to flac. And I would like to be able to determine this in a more scientific way than just listening to the track.

If someone could point out how to use a more generic piece of software for such purposes, that would be helpful too -- in this case I sort of imagine something that displays the relative presence of different frequencies, and guidelines for what to look for to see if a file has been processed by an ogg or an mp3 encoder.

Most often used method is looking at the frequency spectrum. Lossy encodes often but not always have a *sharp* lowpass at 16-18 kHz.

You could give auCDtect (CD Authenticity Detector) a try.
It's freeware, available at TrueAudio (see download section).
Most times it identifies MP3 sourced files correctly, but I don't know it's capabilities with OGG.

.sundance.

Yes, TrueAudio is quite reliable for such test and widely acclaimed.

I doubt it can differentiate a q10 ogg file.

Have you found a place to legally buy music that you think is ripping off their customers?

If so, please tell us about it.

I have tried a few track using Tau Analyzer with Aotuv q-10 and it's give a correct answer.

Looking at sprectrum, even with q10 there will still be a loss of energy at high frequency. not lowpass filter but lower volume. which is easy to see (by no way hear) and maybe because of this the program give a correct answer.

But, with a brand new,legally CD that already have lowpass in the mix. it failed completely. (it say that it's MPEG)