Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sample.eng.ohio-state.edu!purdue!haven.umd.edu!decuac!pa.dec.com!hollie.rdg.dec.com!casee.enet.dec.com!morris
From: morris@casee.enet.dec.com (Tom Morris)
Newsgroups: comp.sys.amiga.audio
Subject: Re: Anyone written a NoiseTracker player for Sun SPARC 1?
Keywords: SPARCstation, NoiseTracker
Message-ID: <1991May2.125306.23861@hollie.rdg.dec.com>
Date: 2 May 91 12:53:06 GMT
References: <1991May1.022337.8905@maverick.ksu.ksu.edu> <231b3678.673126951@fergvax>
Sender: news@hollie.rdg.dec.com (Mr News)
Reply-To: morris@casee.enet.dec.com
Organization: Digital Equipment Corporation, Valbonne, France
Lines: 32

Phil Dietz writes:

|>   1)  SPARCs don't use linear sampling like the Amiga and MAC.  The samples
|>       must be converted to a form called uLaw.  This process compresses
|>       the sample with a process similar to fibonacci.  In the process,
|>       delta values are made and stored rather than the number itself.

The mu-law encoding is not linear, but it is also not a delta coding scheme.
It uses a logarithmic encoding which gives a wider dynamic range at the 
expense of precision in encoding high signal levels.  The conversion from
linear to mu-law can be done with a simple lookup table, so it shouldn't be
very expensive to do.

|> There are two limiting factors that make Noisetrackers a bad descision
|> on a SPARC: 

While the quality of the resulting audio isn't going to be as good as it would
be on an Amiga, I wouldn't be so quick to call such a port a `bad decision.'
It really depends on what your goals are.  I imagine that people with 
workstations that had this audio hardware built-in might be interested in a
software-only solution that would allow them to preview NoiseTracker files,
even at limited quality.

I've even seen a NoiseTracker player for the IBM PC's internal speaker.  It
certainly couldn't be any worse than that!
 
--
Tom Morris				morris@casee.enet.dec.com
Digital Equipment,
Centre Technique Europe S.A.R.L		DTN 828-5729
B.P. 129 - Sophia Antipolis 		Tel. +33 92 95 57 29
06561 Valbonne Cedex - France		Fax  +33 93 65 41 58