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From: bill%thd.tv.tek.com@RELAY.CS.NET (William K. McFadden)
Newsgroups: rec.audio.high-end
Subject: Re: What's up with RDAT?
Message-ID: <11685@uwm.edu>
Date: 2 May 91 12:45:31 GMT
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In article <11578@uwm.edu> ggs@ulysses.att.com (Griff Smith) writes:
>
>I'll admit to a nagging feeling that I'd like to have the whole signal
>recorded, but it's not based on rational behavior.

This isn't as irrational as you might think.  The problem with the DCC
compression scheme is that signal degradation occurs with each
encoding.  Since the process isn't complementary (e.g., lossless), even
digital copying will introduce additional loss (unless it's copied in
compressed form).  Since the SPDIF digital interface uses PCM encoding,
every digital copy will have to pass through another lossy
decode/encode.  After just a few generations, the artifacts may be
audible.

I think this is the real reason record companies like DCC.  High speed
duplication isn't that big of an issue these days.  It's done with
video tapes all the time.  The inability to make perfect copies is what
they really want.

BTW, I have heard demos of MUSICAM and other compression schemes.  They
all sounded very good, certainly better than any analog noise reduction
system I've heard.  However, even my non-golden ears could hear
artifacts.  Solo castanets is the best test signal I've heard for
exploiting the weaknesses of the systems.
-- 
Bill McFadden    Tektronix, Inc.  P.O. Box 500  MS 58-639  Beaverton, OR  97077
bill@videovax.tv.tek.com,     {hplabs,uw-beaver,decvax}!tektronix!videovax!bill
Phone: (503) 627-6920                 "SCUD: Shoots Crooked, Usually Destroyed"