Newsgroups: comp.compression
Path: utzoo!utgpu!cunews2!wilf
From: wilf@sce.carleton.ca (Wilf Leblanc)
Subject: Re: Sound compression
Message-ID: <wilf.675107490@rigel.sce.carleton.ca>
Sender: news@cunews.carleton.ca
Organization: Carleton University
References: <1991May24.083409.20528@looking.on.ca> <91May15.140250edt.750@neuron.ai.toronto.edu> <105539@sgi.sgi.com> <1991May23.123202.18335@cc.tut.fi> <1991May23.215341.7836@nntp-server.caltech.edu> <1991May24.144519.4129@ux1.cso.uiuc.edu>
Date: Fri, 24 May 1991 17:51:30 GMT

mcdonald@aries.scs.uiuc.edu (Doug McDonald) writes:

>It appeared that sound is not redundant at all. All attempts to compress
>digitized sounds have failed in the sense that critical ears can hear the
>difference. Even the 16 bits of present CDs is not completely adequate.
>19 bits probably is, and the 44 kHz sampling rate probably is - given
>really good pre and post analog filtration. 

I agree, 16 bits wasn't enough considering the dynamic range of music.
Some people would argue that 44 kHz isn't enough either.  However,
CD's 16 bits/ 44 kHz is still pretty good, with very little audible
distortion.

>It is true that you can do some really radical things to audio in the
>analog domain -- like screwing up the phase-versus-frequency linearity --
>without audible effect, but that does not reduce the information content
>of the signal.

True, but a good quantizer (and I use the word quantizer loosely),
would know all about this.

>[...]


>There is a LOT of sloppy pseudo-scrience crap in the audio world, and 
>the so-called golden ears often fail to hear certain non-information-losing
>transformations, but the attempts to compress music using informatrion-losing
>methods have all been audible.

Well, above you say that you can really screw up the "phase-versus-
frequency linearity -- without audible effect".  Is this sloppy
pseudo-science crap as well ??

BTW, have YOU heard all the compression techniques (i.e. Sony's
system) and can you say with confidence that the distortion is audible ??

>Doug MCDonald

--
Wilf LeBlanc, Carleton University, Systems & Comp. Eng. Ottawa, Canada, K1S 5B6
Internet: wilf@sce.carleton.ca   UUCP: ...!uunet!mitel!cunews!sce!wilf
                Oh, cruel fate! Why do you mock me so! (H. Simpson)
