SONARC


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SONARC

Sonarc is a new compression technology specifically optimized for digital audio. Think of Sonarc as the PKZip(r) of digitized audio. Unlike the older ADPCM techniques, Sonarc features variable-rate compression which can be reversed to precisely reconstruct the original, uncompressed signal. You don't need to judge its quality by listening to the original and decompressed versions of the signal; just run MS-DOS's COMP or FC commands!

What's the average amount of compression achievable with Sonarc? Obviously, truly random sequences of numbers (white noise) will not compress at all losslessly. On the other hand, there are 8-bit, 22 KHz sound-effects files in products on the market today for which Sonarc achieves an average of 3:1 lossless compression (see below). It all depends upon the quality of the recording and sampling and on the nature of the audio signal being processed.

The grand average compression of all 8-bit, 11 KHz WAVE and VOC files that have been processed so far by Sonarc is about 55% (over 2:1).

Sonarc was not intended to be a general-purpose data compression utility, like the other compressors to which it is compared below. In fact, Sonarc does only a mediocre job of compression on files which contain non-audio data. The following comparison is not for the purpose of denigrating the other compression products, but simply to show how well Sonarc is adapted to the compression of audio data. The four files used in this comparison are probably the most widely distributed audio files in the world, since they come with each copy of Microsoft's Windows v3.1.

Compression and decompression of audio files are accomplished using the programs SONARC.EXE and SONARCX.EXE, respectively.

Both programs use a simple command-line interface. Typing SONARC or SONARCX alone at the DOS prompt will cause the program to display a little "help" screen, explaining the syntax of the command line parameters.

Monaural and stereo, 8-bit and 16-bit files are supported in both WAVE and VOC formats. Creative Labs' new v1.20 VOC files are fully supported.

Neither utility uses extended or EMS memory. Both use less than 256K of conventional memory.

Both utilities run on 8086 processors; however, when processing 16-bit data, they "sense" whether they are executing on a '386 or better, and if so, will use the '386 instruction set for faster execution.