Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!crdgw1!rdsunx!davidsen
From: davidsen@rdsunx.crd.GE.COM (William E Davidsen)
Newsgroups: comp.compression
Subject: Re: Sound compression
Keywords: sound compression
Message-ID: <19524@crdgw1.crd.ge.com>
Date: 14 May 91 19:22:59 GMT
References: <16198@helios.TAMU.EDU>
Sender: news@crdgw1.crd.ge.com
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Organization: GE Corporate R&D Center, Schenectady NY
Lines: 19


In article <16198@helios.TAMU.EDU>, n277cb@tamuts.tamu.edu (Todd Gruben)
writes:
|> 
|> Does anyone know of a good "lossy" sound compression algorithm which I can
|> integrate into a "C" program? 

  I did some 14 => 8 bit compression which worked pretty well, by using
the top three bits of the byte for a shift count to shift the highest 1
bit into the high order bit, dropping the high one bit, and putting the
next five bits in the low part of the byte. Thus full dynamic range and
six bit accuracy (well, almost) and the output was as compressible as
the original. Lossy for sure, but it sounded pretty good when
uncompressed. 

  Sorry I don't have source any more, but the way to quickly find the
high one bit (on a 2's complement machine) is:

  h1bit = n & (-n)