Flac - Sep 2004 - [Flac-users] viewing the fingerprint?

An enthusiastic FLAC user on another list to which I subscribe said that FLAC
has a function to display on screen the stored fingerprint that a FLAC file
has of its source WAV.  That sounds wonderful, because it allows a user to see
whether two differing FLAC files might come from the same WAV but have been
compressed with different sets of options, and therefore they would decompress
to identical WAVs.  Merely verifying that a FLAC file will decode to the WAV
that matches its own stored fingerprint tells you that the FLAC file is a
valid one, but for all you know, since it is déclassé to use MD5 files with
FLACs, it could be a valid FLAC encoding of some other song than the one you
expect.

Unfortunately, I can't find any mention of this feature in the documentation
nor in the front-end's help.  How does one display the fingerprint, or is
there no such feature?

--- "David W. Tamkin" <dattier@panix.com>
wrote:
> An enthusiastic FLAC user on another list to which I subscribe said
> that FLAC
> has a function to display on screen the stored fingerprint that a
> FLAC file
> has of its source WAV.  That sounds wonderful, because it allows a
> user to see
> whether two differing FLAC files might come from the same WAV but
> have been
> compressed with different sets of options, and therefore they would
> decompress
> to identical WAVs.  Merely verifying that a FLAC file will decode to
> the WAV
> that matches its own stored fingerprint tells you that the FLAC file
> is a
> valid one, but for all you know, since it is déclassé to use MD5
> files with
> FLACs, it could be a valid FLAC encoding of some other song than the
> one you
> expect.
Note that the FLAC MD5 sum is not the MD5 of the orignal WAV,
just the audio data.

It is very unlikely ("very" is actually an understatement) for
two different sets of audio data to have identical MD5 sums in
practice.
 
> Unfortunately, I can't find any mention of this feature in the
> documentation
> nor in the front-end's help.  How does one display the fingerprint,
> or is
> there no such feature?
metaflac --show-md5sum filename.flac

I still have to write the documentation for metaflac but the
usage screen covers most everything:

metaflac --help

Josh


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I asked,

| > How does one display the fingerprint?

and Josh himself answered,

| metaflac --show-md5sum filename.flac

That's why I couldn't find it; I didn't think of trying metaflac
instead of
flac.exe itself.  Thank you.

Josh added,

| Note that the FLAC MD5 sum is not the MD5 of the orignal WAV,
| just the audio data.

Hmm.  Thank you for pointing that out.  If ever someone compared a FLAC
file's
stored fingerprint to a direct MD5 of the full WAV file, then, they would
differ.