Thread: st5 question
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Old 2015-10-25, 12:42 PM
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spidergawd spidergawd is offline
Peninsulanwolf
 
Join Date: Dec 2011
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Re: st5 question

Perhaps an analogy/simile would help explain what I was trying to say. Checking flac fingerprints is like checking your fingerprints and saying "you really are you". It doesn't mean that you're healthy, any more than it means that the flac files have not been truncated or damaged in any other way. To test for that you need to take off the flac file's shoes, socks, and gloves and count its fingers and toes, check its blood pressure and do some blood work, turn its head and cough, etc. That's what flac's "test" mode (or st5) does, figuratively speaking.

When the flac is created, the software computes its checksums (fingerprints) and stores it in the file's header (special place for non-audio data). Checking an .ffp file is "usually" just comparing the fingerprints in the .ffp file with the fingerprints in the header. If they match, it just means that you have the correct files. It doesn't mean that they are healthy.

Running flac's "test" mode (or whatever you use for st5) re-computes the fingerprints, and then checks to see if the fingerprints of the current flac file match the fingerprints generated originally. If they match, everything is cool. If they don't, it means that something in the flac file has changed since it was created.

So it's entirely possible for a file to pass an ffp comparison and fail a true st5 test.
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