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*                                                            *
*                         CYBERSPACE                         *
*         A biweekly column on net culture appearing         *
*                in the Toronto Sunday Sun                   *
*                                                            *
* Copyright 1999 Karl Mamer                                  *
* Free for online distribution                               *
* All Rights Reserved                                        *
* Direct comments and questions to:                          *
*                                         *
*                                                            *
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The Internet, originally a text-based medium, grew rapidly 
following the introduction of the World Wide Web. Web pages, as 
you may have noticed, are very good at displaying eye candy.

The Internet and sound have had a much rockier partnership. A 
35 K picture may say a thousand words, but if you want to hear 
a thousand words, you're looking at a 10 meg download.

The traditional format for sound delivery was the Windows Wave 
(.wav) format. Wave files can deliver lush, CD quality sound. A 
10 meg Wave file is great if you're pulling it off your CD, but 
if you're trying to download it over a 28.8 modem, size 
certainly matters. The Toronto Star's netscribe K. K. Campbell 
observed once that you may spend 30 minutes to download a three 
minute song that you determine is crap after the first thirty 
seconds.

Compression is the usual solution for distributing large files 
over the net. Traditional compression schemes work by replacing 
large repetitious sections in a file with small algorithms. 
Text, even my text, is highly repetitious and a compression 
program like Pkzip can reduce it by as much as 70%. (Pkzip 
compresses this column, as a text file, by 53%.) Many images 
can likewise be reduced. For example a picture of forest has 
long streams of green pixels side by side that can be replaced 
by an algorithms that says "look, just display the next 80 
pixels as green."

Sound, however, does not compress very well using this kind of 
scheme. If you look at sheet music, you don't see very many 
tunes that require you to play the same note several times in a 
row.

Two solutions to the problem of trying to pump large sound 
files over slow modems have emerged lately: streaming and lossy 
compression.

Streaming solves the dilemma expressed by K.K. Campbell. 
Instead of downloading the whole sound file, streaming sends 
out data in a format that can be played as it comes in. The 
most popular format on the net is the Real Audio format. A free 
player can be downloaded at www.realaudio.com.

The sound quality delivered by Real Audio is low grade. You'll 
never be able to pump it through your stereo and really dance 
to it, but when heard through $25 computer speakers, the sound 
is quite listenable.

One of the earliest adopters of the format were radio stations. 
For example, Toronto's Q107 (www.q107.com) sends out a Real 
Audio stream in parallel with its live broadcast. Now you may 
wonder why you'd log onto the net to listen to a local radio 
station. Inexplicably I know people who do just that. The more 
exciting merger of Real Audio and radio is it allows access to 
live broadcast from radio stations all over the globe. The Web 
Radio page at www.web-radio.com lets you search for radio 
stations around globe that "webcast."

For audiophiles who demand higher quality sound that's still 
bandwidth friendly, the most exciting development is the mpeg-3 
or mp3 compression standard. Mp3 delivers near CD quality music 
in a file that's about half the size of a non-compressed wav 
file. Mp3's downside is it uses a compression scheme called 
"lossy" (as in "loss" or "to lose"). When you compress a sound 
file using an mp3 encoder, the encoder splits the sound into 
frequencies and then throws out the higher and lower 
frequencies. The assumption is the higher and lower frequencies 
are at the limits of human perception and won't be really 
missed.

To all but the most anal retentive, mp3 doesn't hack out too 
many notes. However, uncompressing and then recompressing a 
file several times using a lossy algorithm can degrade sound 
noticeably.

Like Real Audio, you need a player. The most popular player is 
called WinAmp. A good place to get free mp3 software and tunes 
is at www.mp3.com.


    Source: geocities.com/lapetitelesson/cs/text

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