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A sound idea: MPEG Layer 3 keeps improving
technofile  by al fasoldt
Columns and commentaries in a life-long dance with technology 
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A sound idea: MPEG Layer 3 keeps improving 


Technofile for Jan. 25, 1998

By Al Fasoldt

Copyright © 1998, The Syracuse Newspapers

MPEG audio, the most exciting advance in computer hi-fi since the invention of digital sound, is rapidly gaining popularity on both PCs and Macs. New software for both systems makes it easy to create your own MPEG audio files.

MPEG audio is based on research done by the Motion Picture Experts Group—thus the name "MPEG"—in an effort to pare down the immense size of digital audio sound tracks when movies are recorded on disks. Without special treatment, 64 minutes of hi-fi-quality digital audio takes up about 650 megabytes of storage, but MPEG techniques can slash this by 90 percent or more.

What's most important about MPEG audio is a variation of the technique called Layer 3, developed by the Fraunhofer Institute of Germany (http://www.iis.fhg.de/audio/). Layer 3 can produce a highly compressed digital audio recording that sounds identical to the original in nearly every way. At very high compression rates—squeezing a 24-megabyte hi-fi digital audio file down to 1 megabyte, for example—you'll hear effects of reduced fidelity. (The sound will change from CD quality to mid-fi FM quality.) But at normal compression, Layer 3 is pure magic.

I've written about MPEG Layer 3 before (http://www.dreamscape.com/afasoldt/texts/tec110997.html) and have been creating my own Layer 3 digital audio recordings for about a year. Since my previous article, new Layer 3 encoding software has appeared for both Windows PCs and Macs, and new playback programs are available, too.

First, the playback software. Although both Windows and the Mac operating systems know how to play many kinds of audio formats with no added software, PC and Mac owners cannot play MPEG Layer 3 files without special playback programs. (Microsoft and Apple are both far behind in this area, but I expect both of them to catch up with built-in Layer 3 support before long.)

The best Windows 95 MPEG audio playback software is Winamp, which you can download from http://www.winamp.com/. For Windows 3.1, go to the Fraunhofer site listed above and look for a link to the Windows 3.1 version of Winplay. Mac users should check out http://www.hitsquad.com/smm/mac/ and choose the MPEG link.

You can create your own Layer 3 audio files by converting from WAV audio (on the PC) or standard Mac audio (on the Mac) to MPEG audio. Fraunhofer distributes the nearly universal encoder software for PCs (and for Unix computers and some others, too), while Mac owners can get a decoder from the Mac site listed above.

Windows 95 users probably will want to skip the Fraunhofer software and download an outstanding Dutch encoder program from a programmer known only as SoloH. The program is written in English, runs effortlessly under Windows 95 and Windows NT and can process as many WAV files as you select in its file window. If you have a very fast PC, you can run multiple copies of SoloH's encoder at the same time. (I've run five copies at once on my 233 MHz AMD K6 PC.) The link for the SoloH download page (http://users.bart.nl/~soloh/mpegEnc.html) does not translate well on the printed page, so you should read the Web version of this column and click on the link there.

What many fans of MPEG Layer 3 enjoy most about the method is converting tracks from standard audio CDs into Layer 3 audio files. The entire contents of an audio CD can be stored as Layer 3 files in a relatively small space. Or, if you have a CD-ROM recorder, you can create an MPEG CD that holds the equivalent of 12 audio CDs—one that would play, in other words, for 10 to 12 hours. You could also store one or two CDs on a single 100-megabyte Zip disk.

The best PC program by far for extracting digital audio tracks from audio CDs and converting them to WAV files (so they can then be converted to MPEG audio) is WinDAC32, for Windows 95, by Christoph Schmelnik. Get it from http://www.members.aol.com/schmelnik/dac.html. Windows 3.1 users have many choices, including some programs that work in DOS mode, and there are good Mac programs that do this, also. Windows 3.1 and Mac users can start their search at http://www.hitsquad.com/smm/.


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