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From: warwick@cs.uq.oz.au (Warwick Allison)
Newsgroups: comp.compression
Subject: Compressing SOUND files (8 bit amplitudes)
Summary: How to do this?
Keywords: sound compression
Message-ID: <394@uqcspe.cs.uq.oz.au>
Date: 25 Mar 91 04:55:29 GMT
Sender: news@cs.uq.oz.au
Reply-To: warwick@cs.uq.oz.au
Lines: 31


Sound files I use are of a simple, common format where a series
of amplitude samples, taken at regular time intervals (at about
11KHz, or something).

Does anyone have any information on compressing such a class of
information?  The class no doubt includes many other real-world
samples.

Some obvious things are:

	If samples are taken at very high frequencies, there
	is a high correlation between successive samples, and
	a run-length encoding of DIFFERENCES between successive
	samples would be good.

Unfortunately, most samples are taken at a speed which is JUST
sufficient to capture the sound (2H and all that stuff).

My first guess is that a lossy compression method would perhaps
work well (eg. one which first removes all the `noise' from the
channel).

Any ideas/references?

Warwick.
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