I'm sure there's a thread about this somewhere but here goes...
What is the easiest way to determine if a FLAC is mp3 sourced?
I use Audiochecker but I've heard some criticism of it. I have a lot of shows from around 2000 that have turned out to be mp3 sourced. I suppose this was before torrenting when people shared mp3s on P2P networks then burned them to CDr and eventually re-ripping as WAVE or FLAC.
I find that looking at the Frequency analysis and Spectral view is the best way. Good discussion the topic over at the Trader's Den.
http://www.thetradersden.org/forums/showthread.php?t=4288
A whole forum on lossy or lossless. Lots of info there.
Agree looking at a simply spectrum graph is most revealing. MP3 audio typically has above 12-15K Hz audio totally missing, or if VBR encoded, has the higher frequencies poping up and then disappearing.
Even easier is to just use Traders Little Helper to test for MPEG. Pretty damned accurate.
Analysis > Test wav files for mpeg
TLH can be inaccurate at times, especially on FM sources and stuff that's had noise reduction done.
Yup, read up on this at The Trader's Den. ALL the information is already there.
-Johnny