Flac - Jul 2009 - flac test mode is very useful

I'm uploading some very large flac files, and I've had to use the  
Unix command 'split' to break the files into smaller pieces.  This  
works well, but my only concern is that I want to make sure I get all  
the pieces back together in the right order, without any missing  
pieces or partial files.  "flac -t filename.flac" works perfectly.   
It will detect a truncated file, missing pieces, jumps, and any other  
mistakes I can think of throwing at it.

I wanted to share this in case anyone else needs a quick way to  
verify a flac file that has been copied between machines over  
slightly unreliable transports.

Brian Willoughby
Sound Consulting

On Tue, Jul 28, 2009 at 3:02 AM, Brian Willoughby<brianw at sounds.wa.com>
wrote:
> "flac -t filename.flac" works perfectly.
> It will detect a truncated file, missing pieces, jumps, and any other
> mistakes I can think of throwing at it.
yes flac -t is a life saver because relying on md5sum --check to test
against previously stored metaflac --show-md5sum is not sufficient,
i have had files get truncated several times and pass that test but
of course flac -t flagged them

this made me wonder if maybe the checksum shouldn't be stored
at the beginning and end of the flac file but maybe not worth it

also, if you don't use md5check perl script you should!
it recursively finds all md5 sigs in.txt files and checks them and
does flac -t also - has saved me many times...

If md5sum --check did not return an error with a truncated file, then the
file was likely broken to start with. I think the chances of a corrupted
file generating the same md5sum is close enough to 0 that you will never see
it in a life time.

Also, you lost me on storing the md5sum value at the begging and the end?

On Wed, Jul 29, 2009 at 4:44 AM, Dat Head <dathead2 at gmail.com> wrote:
> On Tue, Jul 28, 2009 at 3:02 AM, Brian Willoughby<brianw at
sounds.wa.com>
> wrote:
> > "flac -t filename.flac" works perfectly.
> > It will detect a truncated file, missing pieces, jumps, and any other
> > mistakes I can think of throwing at it.
>
> yes flac -t is a life saver because relying on md5sum --check to test
> against previously stored metaflac --show-md5sum is not sufficient,
> i have had files get truncated several times and pass that test but
> of course flac -t flagged them
>
> this made me wonder if maybe the checksum shouldn't be stored
> at the beginning and end of the flac file but maybe not worth it
>
> also, if you don't use md5check perl script you should!
> it recursively finds all md5 sigs in.txt files and checks them and
> does flac -t also - has saved me many times...
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