[Flac-dev] MD5 Signature Mismatch

[Brian Willoughby]

I have a hardware device which records directly to FLAC.  I have  
found that the MD5 signature is not created during recording,  
probably because it would delay the process to calculate the MD5 on  
hours of music after you push stop.  It's much easier to calculate  
when converting existing audio rather than when recording new audio.   
Anyway, my point here is that it is possible for a FLAC file to exist  
without an MD5 signature, so my first suggestion is to learn how to  
distinguish between a true "mismatch" and simply a "missing" MD5.  I  
must admit that I don't pay attention, since I only get the warnings  
when dealing with FLAC files from live recordings, never from  
converted AIFF or WAVE.

As for why this is happening in the specific situations you've  
described, I have no idea.  My suggestion is to first gather more  
information, by learning how to confirm whether an MD5 Signature even  
exists in these files before continuing to determine the reason for  
the mismatch.

Maybe someone else has more information.

Brian Willoughby
Sound Consulting


On May 31, 2011, at 19:20, Scott C. Brown 02 wrote:
>
> I found an old thread from 2007:
>
> http://www.mail-archive.com/flac@xiph.org/msg00702.html
>
> I have a user who is getting this same "MD5 Signature mismatch."
>
> 2 times he told me he got it today:
>
> 1 time: using the flac 1.2.1 encoder (command line compiled from  
> official flac
> src) on a g5 (power pc) mac, he created a file set and uploaded to  
> archive.org.
>   archive.org uses flac 1.2.1 to test the files and then convert  
> them to ogg/mp3.
>   the test step gave "MD5 signature mismatch."
>
> 2nd time: he opened a flac file created on the power pc mac on a  
> windows machine
> in CD wav and split it up into 3 flac files.  he then copied the  
> files back onto
> the power pc mac and tried to decode them.  flac 1.2.1 (command  
> line compiled
> from src) gave an "md5 signature mismatch" error
>
> he ran a ram test and Techtool Pro reported his ram to be ok.   
> Anyone have any
> idea what's causing the issue?
>
> Scott