SSSSSSS       OOOOO     N         N       A       RRRRRRR        CCCCCC
   S       S     O     O    NN        N      A A      R      RR     C      C
  S         S   O       O   N N       N     A   A     R        R   C        C
  S            O         O  N  N      N    A     A    R        R  C
   SSS         O         O  N   N     N   A       A   R      RR   C
      SSS      O         O  N    N    N  A         A  RRRRRRR     C
         SSS   O         O  N     N   N  AAAAAAAAAAA  R   R       C
            S  O         O  N      N  N  A         A  R    R      C
  S         S   O       O   N       N N  A         A  R     R      C        C
   S       S     O     O    N        NN  A         A  R      R      C      C
    SSSSSSS       OOOOO     N         N  A         A  R       R      CCCCCC







                SONARC: Digital Audio Compression, Version 2.1i
                ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ





                     (C) Copyright 1994 Speech Compression
                              All Rights Reserved










                            U S E R    M A N U A L



                                   June 1994

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  i
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß


                                   CONTENTS


INTRODUCTION .......................................................... 1

THE UTILITIES ......................................................... 2

  SONARC.EXE .......................................................... 2

  SONARCX.EXE ......................................................... 5

LICENSING INFORMATION ................................................. 6

OTHER LICENSABLE MODULES .............................................. 7

  SONLIB.DLL .......................................................... 7

  LINKABLE OBJECTS .................................................... 9

POSTSCRIPT ........................................................... 11




                               LEGAL MUMBO-JUMBO
                                      AND
                         ACKNOWLEDGMENT OF TRADEMARKS

Even though Speech Compression has tested the Sonarc software and reviewed
the documentation, SPEECH COMPRESSION MAKES NO WARRANTY OR REPRESENTATION,
EITHER EXPRESSED OR IMPLIED, WITH RESPECT TO SONARC SOFTWARE, ITS QUALITY,
PERFORMANCE, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE.  AS A
RESULT, THIS SOFTWARE IS PROVIDED "AS IS", AND YOU, THE USER, ARE ASSUMING
THE ENTIRE RISK AS TO ITS QUALITY AND PERFORMANCE.

IN NO EVENT WILL SPEECH COMPRESSION BE LIABLE FOR DIRECT, INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM ANY DEFECT IN SONARC
SOFTWARE OR ITS DOCUMENTATION, even if advised of the possibility of such
damages.  In particular, Speech Compression shall have no liability for any
programs or data used with Sonarc software, including the cost of recovering
such programs or data.


Sonarc, Sonarcx and ZipTalk are trademarks of Speech Compression.

Microsoft and MS-DOS are registered trademarks and Windows is a trademark of
Microsoft Corporation.

BORLAND is a registered trademark of Borland International, Inc.

PKZIP is a registered trademark of PKWARE Inc.

All other brand and product names mentioned are trademarks or registered
trademarks of their respective holders.

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  1
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß
 
                                 INTRODUCTION

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.

    File      Original size     LHA v2.13     PKZIP v2.04g   Sonarc v2.1i
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ
  CHIMES.WAV     15,920           8,680          8,690          4,170
  CHORD.WAV      24,982           9,407          8,861          7,174
  DING.WAV       11,598           4,704          4,630          2,184
  TADA.WAV       27,804          18,388         18,566         11,528
                 ÄÄÄÄÄÄ          ÄÄÄÄÄÄ         ÄÄÄÄÄÄ         ÄÄÄÄÄÄ
                 80,304          41,179         40,747         25,056

The command-line option -ex (Maximum Compression) was used with PKZIP.
Sonarc used the command-line options -o0 and -x for maximum compression.

The compressed file sizes reported for LHA and PKZIP are the internal file
sizes and do not include the archive directory overhead.

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  2
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

                                 THE UTILITIES

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.

SONARC.EXE (file-to-file compression program)
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

The syntax for invoking SONARC is:

        SONARC {-<option>} <input-file> [<output-file>]
or
        SONARC {-<option>} <wildcarded-name> [<dest-path>]

If the input file has an extension, then it must be supplied.  If the input
file is not in the current directory, then the path needed to reach it from
the current directory is also required.

The output file specification is optional.  If it is omitted, then the output
file will be created in the current directory with a name which is formed by
concatenating the root name in the input file with one of the extensions
shown below.  If it is supplied, then a path can be specified to cause the
output file to be written to a directory other than the current directory.
If no extension is specified for the output file, the extension will be WV,
VC, or SNC, depending on whether the input file is in WAVE, VOC, or another
format, respectively.  (SONARC scans the beginning of the file for a WAVE or
VOC header.  If it finds neither, it assumes the file is "raw", i.e., contains
only audio samples; it then prepends its own header to the output file.)

Alternatively, a wild-card specification (with source path, if needed) can be
used.  If a destination path is supplied, the output files will be written to
that path, otherwise to the current directory.  Any destination name or
extension will be ignored.

If the input file to Sonarc is a WAVE file, then the output file is also a
WAVE file in a special, proprietary format which has been registered with
Microsoft's Multimedia Product Management.

Although the letter options are shown on the next page in upper case, they can
be entered in either upper or lower case.  The option prefix character may be
either a '-' or '/'.

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  3
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

The command-line options for SONARC.EXE are:

        Q        quiet mode: no banners, no statistics, no warning for
                 overwriting existing files.

        D        delete the input file upon successful operation.

        S[n]     assume stereo (two interleaved tracks), or "n" interleaved
                 tracks if the optional number "n" is specified.  The default
                 is to assume that the "raw" file is monaural.
                 (Only obeyed for "raw" files.)

        16       assume 16-bit samples.  The default for "raw" files is to
                 assume that they are all 8-bit samples.  Options S and 16 may
                 be used together to compress "raw" 16-bit, stereo files.
                 (Only obeyed for "raw" files.)

        Fnum     set the frame size to num in the range 256-4096.  Sonarc
                 divides the source into "frames" of that many samples each.
                 The compressed file then consists of compressed "frames",
                 each of which contains table data specific for that frame.
                 If the frame size is too small, then the size of the table
                 data will not be amortized over enough compressed samples
                 and the compression ratio will suffer.  If the frame size is
                 too big, then spectral changes within the frame will not be
                 tracked accurately enough, and so the compression ratio will
                 suffer for that reason.  Different files will have different
                 "optimal" values for frame size.  This option overrides the
                 default frame size of 2048.

        Onum     set order to num in the range from 0 to 30.  "Order" is
                 the number of previous samples to take into consideration
                 when attempting to predict the next sample.  This option
                 fixes the order to the number specified, except that a num
                 of 0 causes the program to "search" for the best value of
                 order for each frame.  This added searching will slow the
                 compression process substantially, but generally yields more
                 compression.  The default order is 10.

        X        use floating-point calculations to analyze the signal more
                 thoroughy than is otherwise done.  Setting this option will
                 slow the compression process moderately, or immoderately if
                 combined with the -o0 option described above.  The floating-
                 point code uses Borland's "sensing" library that uses a co-
                 processor if detected at run time.  A co-processor is not
                 necessary, but is highly recommended nevertheless for the
                 sake of compression speed.

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  4
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

Examples:

    SONARC C:\WIN31\*.WAV
        Compress all the .WAV files in the C:\WIN31 directory and write the
        output to the current directory

    SONARC /D ILBEBACK.WAV ..
        Compress ilbeback.wav in the current directory to ilbeback.wv, in the
        parent directory.  Erase ilbeback.wav if no errors occur.

    sonarc -q *.voc d:
        Compress all the .VOC files in the current directory and write the
        corresponding .VC files to the current directory of the D: drive.
        Suppress all screen output.

    sonarc piano.sou pno
        (assuming piano.sou is "raw":) Compress piano.sou to pno.snc

    sonarc -s piano.sou pno.cmp
        Compress piano.sou to pno.cmp; assume the samples are interleaved
        stereo tracks

    sonarc -16 piano.sou pno.
        Compress piano.sou to pno; assume piano.sou is sampled at 16 bits

    sonarc -x -o0 g145.wav
        Compress g145.wav for maximum compression ratio, at the expense of
        considerable extra time in compressing the file

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  5
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

SONARCX.EXE (file-to-file decompression program)
ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

The syntax for invoking SONARCX is:

        SONARCX {-<option>} <input-file> [<output-file>]
or
        SONARCX {-<option>} <wildcarded-name> [<dest-path>]

The input (compressed) file specification requires the file's extension, if
any.  (This will be the extension specified for the output file during the
execution of SONARC, or else WV, VC, or SNC, if no extension was specified.)

If the input file is not in the current directory, then the path needed to
reach the file from the current directory is also required.

The output (decompressed) file specification is optional.  If it is omitted,
then the output file will be created in the current directory with a name
which is formed by concatenating the root name in the input file with one of
extensions described below.  If it is supplied, then a path can be specified
to cause the output file to be written to a directory other than the current
directory.  If no extension is specified for the output file, the extension
will be WAV, VOC, or the original file's extension in the case where the
original file was not in either WAVE or VOC format.

Alternatively, a wild-card specification (with source path, if needed) can
be used for specifying the input (compressed) files.  If a destination path
is supplied, then the output (decompressed) files will be written to that
path, otherwise to the current directory.  Any destination name or extension
will be ignored.

Since Sonarc is a LOSSLESS compression technology, the decompressed and
original files will differ only in their timestamps.  They will otherwise
compare identically, using the FC or COMP commands in DOS.

The command-line options for SONARCX.EXE are:

        Q      quiet mode: no banners, no statistics, no warning for 
               overwriting existing files.

        D      delete the input file upon successful operation.

Examples:

    SONARCX *.WV
        Decompress all the .WV files in the current directory and write the
        reconstructed files to the current directory

    sonarcx -q *.vc d:\
        Decompress all the .VC files in the current directory and write the
        corresponding .VOC files to the root directory of the D: drive.
        Suppress all screen output.

    sonarcx pno.snc piano
        Decompress pno.snc to piano.sou (if "sou" was the extension on the
        original file, stored in the pno.snc file header).

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  6
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

                             LICENSING INFORMATION

What you may do with Sonarc depends on what classification you fall under.
The archive referred to is the SNRC21.ZIP file from which this file was
extracted.

1. Shareware distributors, computer clubs and user groups:

  Members of this category are permitted to distribute this archive along with
  other shareware programs as long as the charge for the diskette containing
  this archive does not exceed US$10.

2. Bulletin-board services:

  You may post this archive freely for the downloading convenience of your
  customers.
  
  You may add a comment to the archive promoting your BBS.  Please inform me
  if you do this.

  You may use Sonarc to compress any sound files in your possession and offer
  the Sonarc-compressed files for downloading by your customers as long as
  doing so does not violate any copyrights.  Please inform me if you do this.

3. All other organizations (for-profit, not-for-profit, or governmental):

  After an evaluation period not to exceed 120 days, your organization must
  either license the software from Speech Compression or destroy all copies
  in its possession.

  For its internal use only, the organization must obtain a Site License.
  For use in distributed products, the organization must obtain a Distribution
  License.  These are available from the contact address below.

4. Individuals (not including fictitious persons, such as corporations):

  You may use Sonarc in any way you want for as long as you want, as long as
  it's not-for-profit.  This software is being distributed as shareware, i.e.,
  "try before you buy."

  You may make copies of this archive and distribute it freely or upload it
  to BBS's.  You are required to keep the component files of this archive
  together, unmodified.

  You are cordially invited to send in a registration fee of $20 if you find
  this software useful.  In exchange, you will receive one free upgrade of the
  next version of Sonarc (v2.2 with a "lossy" algorithm) when it becomes
  available.  You will also get the satisfaction of paying for value received.

  Please send your check made out to "Speech Compression", along with your
  name and address (if not already imprinted on the check), to:

                             Speech Compression
                             1910 W. Pawnee Lane
                             Colbert, WA  99005-9401

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  7
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

                     OTHER LICENSABLE MODULES: SONLIB.DLL

A DLL version of the SONARCX.EXE utility is also available for licensing.
This DLL is useful for applications which install under Windows and use lots
of WAVE files.  It is described in detail below.  It is available for
licensing by contacting Speech Compression at the address on the previous
page.

The SONLIB.DLL library has just a single callable function at index 1.  The "C"
calling interface is as follows:

    extern int far pascal sonarcx(char* infyl,
                                  char* outfyl,
                                  int   EraseInputFile,
                                  int   ShowNames);

or, in Pascal,

    function sonarcx(infyl, outfyl: pchar;
                     EraseInputFile,
                     ShowNames: Boolean): integer; far; external;

The type "pchar" is a Borland extension to Pascal which is a pointer to a 
C-style, null-terminated string.

The first argument, infyl, may be wildcarded, in which case the second 
argument, outfyl, should be the empty string '' or a destination path.  The
third argument, EraseInputFile, has the same effect as the "-D" option in the
SONARCX utility, that is, it causes the input file to be erased after
successful completion.

The fourth argument, ShowNames, has the inverse effect of the "-Q" option in
SONARCX.  If false, no screen I/O occurs whatsoever.  If true, however, it
writes the name of the file currently being decompressed in an area of the DLL
caller's active window.

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  8
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

                 OTHER LICENSABLE MODULES: SONLIB.DLL (cont.)

The function result is 0 if there were no errors detected.  The following are
the error codes and conditions that may be returned:

-17      16-bit file encounted by a DLL configured to process only 8-bits.
-16      .WV file was produced by a later version of Sonarc than v2.1.
-15      specify output file name different from input file name.
-14      bad block type in .VC file.
-13      corrupted VC format file header.
-12      input file is not a Sonarc-compressed file.
-11      input file is an uncompressed VOC file.
-10      internal error: corrupted frame data.
 -9      version mismatch: compressed VOC file is obsolete version.
 -8      unknown chunk type in data list.
 -7      internal error: mismatch in sample count.
 -6      missing "fact" chunk.
 -5      "fact" chunk has corrupted length field.
 -3      WAVE file is already in uncompressed format.
 -2      WAVE file already compressed using another vendor’s process.
 -1      internal error: bad frame checksum (corrupted frame).
  2      File not found.
  3      Non-existent drive, sub-directory or badly formed file name.
  5      Name is directory or existing read-only file.
100      Attempt to read past end of file: probably corrupted sound file.
101      Disk full.
150      Disk is write-protected.
152      Drive not ready.
162      Hardware failure.

Other error codes may be returned from DOS for various I/O operations.

SONARC version 2.1i    Copyright 1994 Speech Compression              Page  9
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

                  OTHER LICENSABLE MODULES: LINKABLE OBJECTS

There are also assembly-coded buffer-to-buffer compression and decompression
routines available which are highly optimized for both space and speed.  The
interfaces for these routines are described in detail below.

Organizations wishing to obtain copies of these linkable modules must contact
Speech Compression at the address on page 6.

The "C" declarations for the 8- and 16-bit compression routines are:

    typedef unsigned char[max_buf_len]* p_bytary;

    extern int far pascal cmp8(p_bytary p_input,
                               int in_size,
                               p_bytary p_output,
                               int out_max,
                               int order);

    typedef int[max_buf_len]* p_intary;

    extern int far pascal cmp16(p_intary p_input,
                                int in_size,
                                p_intary
                                p_output,
                                int out_max,
                                int order);

The corresponding Pascal declarations are:

    type bytary = array [0..max_buf_len-1] of char;
         p_bytary = ^bytary;

    function cmp8(p_input: p_bytary;
                  in_size: integer;
                  p_output: p_bytary;
                  out_max, order: integer;
                 ): integer; far; external;

    type intary = array [0..max_buf_len-1] of integer;
         p_intary = ^intary;

    function cmp16(p_input: p_intary;
                   in_size: integer;
                   p_output: p_intary;
                   out_max, order: integer;
                  ): integer; far; external;

Both cmp8 and cmp16 take a buffer of order+in_size samples at p_input and
compress the in_size samples beginning at p_input[order] into the output buffer
at p_output, not to exceed out_max bytes.  Note that for cmp16, the size of the
input buffer is 2*(order+in_size) bytes, since each sample is 2 bytes. Both
p_input and p_output are far, i.e., 32-bit, segmented pointers.  The argument
out_max is the size of the output buffer into which the compressed frame is
copied.  Note that this is not the size of the compressed frame; that
information is stored into the first 16-bit word of the frame itself.  The
argument out_max is passed to the routine to prevent it from producing a frame
larger than the output buffer whose address is passed in.

SONARC version 2.1i    Copyright 1994 Speech Compression              Page 10
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

The function result is returned in the AX register, where most "C" and Pascal
compilers expect it.  The result value is zero for normal, error-free
processing.

Two error conditions are possible.  If insufficient stack space is allocated, a
result of -2 is returned.  This occurs if the SP register is less than 
approximately 2*order+184 at the time of the call to cmp8, or less than
2*order+364 at the time of the call to cmp16.  (Note: This is a change from
prior versions where enough stack space had to be allocated to copy the entire
input buffer.)

The second error condition occurs when the number of bytes of output buffer
needed for the compressed input buffer exceeds the value of out_max, in which
case a result value of -1 is returned.

ÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄÄ

The "C" declarations for the 8- and 16-bit decompression routines are:

    extern int far pascal dcmp8(p_bytary p_input,
                                p_bytary p_output);

    extern int far pascal dcmp16(p_intary p_input,
                                 p_intary p_output);

The corresponding Pascal declarations are:

    function dcmp8(p_input,
                   p_output: p_bytary
                  ): integer; far; external;

    function dcmp16(p_input,
                    p_output: p_intary
                   ): integer; far; external;

Both dcmp8 and dcmp16 take a compressed frame at p_input and decompress it into
the output buffer starting at p_output[order].  The decompression routine gets
the order datum from the byte at offset 7 in the input v2.1 compressed frame
(see the frame header description in the File and Frame Formats section).  As
previously explained, the header of the compressed frame contains, at fixed
offsets, the lengths needed by the caller and the decompression routine to
figure out how much buffer space to allocate and use, respectively.

As is the case for the compression routines, the function result is returned in
the AX register.  The result value is zero for normal, error-free processing. 
The only error condition, resulting in a returned value of -1, is if the
checksum fails.  If this error occurs, it means that the input frame has been
folded, spindled, and/or mutilated at some point following its creation by the
compression routine.  Keep in mind that the entire frame must be passed to the
decompression routine; partial frames cannot be decompressed.

Note that stack overflow is not checked for in the decompression modules.
However, the stack space required by these routines is guaranteed to be less
than 50 bytes.

The DS, SS, CS, BP, SI and DI registers are preserved by these routines.  No
instructions unique to the '186, '286, '386, or '486 processors are used in the
8-bit modules.  The 16-bit modules, however, make use of the '386 instruction
family whenever they "sense" that they are running on a '386 or better.

SONARC version 2.1i    Copyright 1994 Speech Compression              Page 11
ßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßßß

                                  POSTSCRIPT

I picked the d.b.a. "Speech Compression" in 1992, when I started working on a
technology for PCs capable of compressing speech signals lossily at ratios of
over 10:1.  Currently no compression is available for speech at such ratios
(of any quality, that is) that does not require either huge run-time tables
(>100 Kbytes), or some sort of special hardware support, such as a DSP chip.

I got ZipTalk (as I called it) developed to the point where I could prove to
myself that decompression of speech signals could be accomplished on an 8088
processor running at 4.77 MHertz with processor to spare, using tables of
probably not much more than 16K bytes.

The compression side is a complex, but solved, problem since it piggy-backs
off of linear-predictive analysis.  In fact, the whole trick is to transform
frequency-domain parameters obtained through LPC techniques into a special
format that I have discovered, which then permits real-time conversion back
into time-domain signals.  (I can say it faster than I can develop it!)

However, while waiting for some research documents to arrive by USnail, I was
put in contact with a company which needed lossless audio compression, and I
diverted my energy to the development of Sonarc.  (If you need Sonarc to be
an acronym of something, and you don't like "SOuNd ARChival" then I suppose
it could be "Some Outfit Nagged About Reversible Compression".)

I've spent a considerable amount of time researching various ways of doing
"lossy" audio compression.  Earlier versions of Sonarc featured a "lossy"
parameter -Ln[n], which achieved higher compression ratios while keeping the
total amplitude distortion in the decompressed signal less than n.[n]%.
Unfortunately, the compression phase was extremely compute-intensive and
generally required overnight runs to compress any significant amount of audio
files.  I've never tried combining this "lossy" with the -x and -o0 options;
I suspect there would be a measurable amount of proton decay before it could
finish.  I only left it out of this shareware version because it is so slow,
and I didn't want that sullying Sonarc's otherwise fine reputation.  I'm still
developing the "lossy" algorithm, though, and I'll have a "lossy" solution in
the v2.2.  Don't ask me when; it'll be ready when it's ready.

I suppose, in retrospect, I might have called myself "Sound Compression" or
some such (not being particularly imaginative in the naming department).  But
I'm stuck with "Speech Compression", even though I now do general audio
compression.

Sonarc is now being used as an installation utility in PC titles published by
Interplay, Origin, and The Software Toolworks, among others.  Inquiries are
welcome.  Contact me at 76635,3652@compuserve.com or voice phone (mail) at
509-466-2925.

                             Richard P. Sprague