[Flac] Checking file integrity

[Anton Shepelev]

J.B. Nicholson-Owens:

> I'm not sure what you're asking for

I  have  a huge archive of FLAC files and want auto-
matically to check the integrity thereof, so  as  if
some  file be reported as corrupted I can restore it
from a mirror backup.

> I should have mentioned before that apparently the
> MD5  hash is computed on the uncompressed raw sam-
> ple data and the easiest way  to  check  the  FLAC
> file is with
>
>        flac --verify audio.flac
>

This  doesn't work, and the official FLAC focumenta-
tion says this option  is  only  applicable  to  WAV
files:

    -V, --verify
        Verify  the  encoding process. With this
        option,  flac  will  create  a  parallel
        decoder  that  decodes the output of the
        encoder and compares the result  against
        the  original. It will abort immediately
        with an error if a mismatch  occurs.  -V
        increases the total encoding time but is
        guaranteed to catch any unforseen bug in
        the encoding process.

It seems to have nothing to do with the MD5 hash.

The  procedure  you  have described in your previous
reply is quite complicated for an  automatic  check-
ing.  Why  does FLAC calculate MD5 on the RAW uncom-
pressed data?  If  it  were  using  compressed  data
instead  the checking wouldn't require decompression
and would be quicker: just calculate the hash on the
binary  file  and  compare  it  against  the  stored
value...

Anton