On Tue, 5 Feb 2008 23:25:36 +0000, Don Pearce wrote
On Tue, 5 Feb 2008 21:01:32 +0000, Stimpy
wrote:

I've been sent some .mp3 files that claim to be 320 kbps but they sound
pretty ropey. Is there any way I can detect if they've been re-encoded
from a lower bitrate?

Do an FFT- the maximum frequency they contain will be a clue. If they
are native 320k, they should go all the way to 20kHz; if they have
been 128k at some point, they will probably stop somewhere around
16kHz.

That's good advice, thanks. I'm afraid I'm a bit dumb when it comes to
technical stuff, what's a FFT? Is there a tool you'd recommend I use to
check the mp3 in question?

Thanks again