Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uwm.edu!csd4.csd.uwm.edu!info-high-audio-request From: d87parfo@odalix.ida.liu.se (Par Fornland) Newsgroups: rec.audio.high-end Subject: Re: data compression Message-ID: <11989@uwm.edu> Date: 9 May 91 12:54:23 GMT Sender: news@uwm.edu Lines: 33 Approved: tjk@csd4.csd.uwm.edu Originator: tjk@csd4.csd.uwm.edu 09nilles%cuavax.dnet@netcon.cua.edu (Fiver Toadflax) writes: >> From: "William K. McFadden" >> >> This isn't as irrational as you might think. The problem with the DCC >> compression scheme is that signal degradation occurs with each >> encoding. > >I haven't seen the details(algorithm) of the DCC compression scheme, but >if it is any decient, nothing will be lost. ... >compression routine should not have, on the average any data loss. It isn't really compression in the computerized sence, but instead it is more of the kind of compression you do e.g. to the voice of a singer in rock/popmusic, i.e. amplitude compression. In DCC you compress the amplitude so that low amplitudes have higher resolution than high ones. Thus you have virtually more bits resolution than you actually save on the DCC. This is called robust quantization in Digital Communication by Simon Haykin. The distortion increases with amplitude, just like a LP. On a CD the dist. decreases with amplitude. I would suspect that in a strong passage of _very_ complex music, one may hear a difference. -- ------- Sound's good, HiFi's better but Music is the Ultimate! But I think John Cage would disagree! ("Sound's all", he'd say...) d87parfo@odalix.ida.liu.se - Telephone (Sweden)-013-260486 Par Fornland, Bjornkarrsg. 10c:10, 582 51 Linkoping, Sweden