"Paul Stamler" wrote in message
...
"Serge Auckland" wrote in message
...
As to your OP, I think you are asking for a piece of (free) software that
will analyse for any "footprint" left behind by MP3 compression. I have
never come across any such software, free or otherwise
Well, you could look for a 15.8kHz hard bandlimit on the audio using the
frequency analyzer in a DAW. That would indicate the likelihood that a
128kbps .mp3 was part of the chain. It's still pretty unlikely, though,
unless the recording is something like a live gig issued by the band
itself,
perhaps from a portable .mp3 recorder.
A hard bandlimit may indicate the possibility of a 128k MP3, but
band-limiting can indicate also that a lower sample rate was used:- 32k
sample rate was regularly used in the past for ISDN audio transfers, if the
intended outlet was FM transmission. Higher bit-rate MP3 would not
necessarily have the band-limiting except the normal anti-aliasing filter
common to all PCM digital audio.
Not impossible, though. Hey, I once co-produced and mastered an album from
a
hodgepodge of sources, and one track on it was from MiniDisc, which uses
perceptual-coding algorithms not too conceptually different from those in
the .mp3 format. It's Art Thieme's "The Older I Get, The Better I Was" on
Waterbug. I'd be surprised if someone can tell me which track it was by
ear
(no cheating and looking at the liner notes!)
Peace,
Paul
And some albums were recorded on Tascam Portastudios (4 track analogue
cassette), which, arguably, sound a lot worse than MP3 at higher bit rates,
domestic reel-reel machines and other sources.
S
http://audiopages.googlepages.com