[Flac] FLAC suddenly compresses more - why?

[Brian Willoughby]

On Dec 27, 2010, at 07:10, Fernando Alberto Marengo Rodriguez wrote:
> If you want to be sure that you get no information loss, I suggest  
> a very simple test. Recover your WAV file from any of the FLAC  
> files you mentioned in your e-mail. If this WAV file is bit-by-bit  
> identical to the input WAV file, then you have no information loss.

This is a good test, but keep in mind that only the audio part of the  
WAV file will be identical.  There are non-audio parts to a WAV file,  
and those may be lost or changed when compressed, so you will need  
some method of comparing only the audio and not the rest of the  
file.  In other words, a basic file to file compare might fail even  
if the audio is the same.

I'm not sure how to compare the audio part only, at least not  
easily.  You can place each file in the same DAW, but with one set  
for inverted polarity.  Then mix them together and you should get  
silence.  But that is not an easy or simple test.

Brian Willoughby
Sound Consulting