Pale Blue Ego;275677 Wrote: 
> I know the resulting file isn't true 24-bit, but it *is* a
> properly-decoded HDCD wav
I'm not sure we can be sure that it's "properly decoded", since the
HDCD specs are "secret".  As I understand it, hdcd.exe was reverse
engineered without a real specification in hand, and while it applies
dynamics processing using probably "correct" algorithms, it does not
apply filter algorithms, which apparently are also part of the "secret"
HDCD spec.

In fact, the patent contemplates digital output of the decoded signal
from a CD player (although I know of none which do).  It states that
the decoded output would be at 88.2 KHz sample rate, probably with the
intention that the various digital filter algorithms it can specify
would up-sample.  Certainly, hdcd.exe does not do this, and I don't
think Windows Media Player does, either.  Microsoft now owns HDCD, so
they should know, but maybe they're just being sloppy...

Personally, I'm sort of "on the fence" as to whether I think the result
of hdcd.exe is always an improvement.  I'm extremely glad it was
written, and am glad I now have the option of using it.  Under the
circumstances, it was a great achievement, but the damn Microsoft
secrecy surrounding the official specs makes me wonder if any of us can
truthfully say that it results in a "properly decoded WAV".


-- 
Timothy Stockman
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