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Path: utzoo!watmath!clyde!burl!ulysses!allegra!bellcore!decvax!tektronix!hplabs!nsc!voder!gino
From: gino@voder.UUCP (Gino Bloch)
Newsgroups: net.audio
Subject: Re: CD Reflections
Message-ID: <634@voder.UUCP>
Date: Tue, 15-Jan-85 13:25:13 EST
Article-I.D.: voder.634
Posted: Tue Jan 15 13:25:13 1985
Date-Received: Sat, 19-Jan-85 00:19:07 EST
References: <15100001@hpfcmp.UUCP> <3411@mit-eddie.UUCP> <1420@hplabs.UUCP>
Organization: National Semiconductor, Santa Clara
Lines: 16

> > The use of a higher sampling rate (oversampling) is used [to simplify
    analog filtering]
> It seems to me that the disc itself was created with a given sampling rate.
> How can a player change this?
I wondered the same thing and asked the right person.  Fictitious samples are
added to increase the number of samples, then digital filtering and analog
filtering are applied.  Intuitively, you might expect the fictitious samples
to be interpolations of the samples already present, but what is done is to
intersperse zeros.  The subsequent digital filtering makes this OK, but to
prove it you have to write `FFT' on your hands with magic markers and then
do some hand-waving.  Find a friend who actually knows digital signal
processing (I don't, as I'm sure you can readily tell) and ask them (see
net.nlang) to explain it.
-- 
Gene E. Bloch (...!nsc!voder!gino)
Extend USENET to omicron Ceti.