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Old September 5th 16, 04:12 PM posted to uk.rec.audio
Jim Lesurf[_2_]
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Default MQA alternative - open source

In article , Johan Helsingius
wrote:
How is bit freezing different from simply converting 24-bit FLAC/ALAC
files to 16 bits (with appropriate dithering)?


Just to check: Have you already looked at the webpages I wrote on this a
while ago? If not, they do give some of the background, etc, which may
help.

The bitfreezing is discussed and exampled on
http://www.audiomisc.co.uk/MQA/cool/bitfreezing.html

but these two pages preceeded it to look at MQA and get this into context

http://www.audiomisc.co.uk/MQA/origa...reAndBack.html
http://www.audiomisc.co.uk/MQA/bits/Stacking.html

So reading those first might be useful.

More specifically, bitfreezing lets you choose how many bits per sample to
'freeze'. Simply converting down to 16 bits nominally means losing 8 bits
per sample if you start from 24 bit. That may be too much or too little for
a given recording.

But with bitfreezing you can remove, say, 6 bits per sample. Hence you can
tailor this optimally for the amount of excess noise bits in the given
input material. i.e. remove only over-specified noise.

Indeed, in some cases you may find that high sample rate material has a
wideband noise floor distinctly *above* the 16 bit level. So might choose
to freeze some of the LS bits in a 16bit recording.

Beyond that, it comes down to being a case-by-case decision.

Jim

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