Category : Music and Digitized Voice
Archive   : DASCMP10.ZIP
Filename : DASCMP.DOC

 
Output of file : DASCMP.DOC contained in archive : DASCMP10.ZIP
/----------\
| TAG | Presents
| SOFTWARE | . . . . Digital Audio
\----------/ Sound Compressor 1.0

Digital Audio Sound Compressor 1.0 (DASCMP/DASEXP) are
programs that allow you to compress (and decompress) .WAV and
raw sound files.

Sound files can use up a very large amount of disk space.
Understand that a high quality 8-bit sound file sampled at
23kHz uses 23,000 bytes every second. Things will only get
worse when the newer sound cards with stereo and higher
sampling rates prevail in the market. Imagine a 44kHz stereo
16-bit sound file. Only 10 seconds of sound will tie up
1,760,000 bytes (44,000 * 2 * 2 * 10). No wonder the
Multi-Media standard calls for a CD-ROM.

We at TAG SOFTWARE have been working on this problem. We
have come up with a compression technique that generally
achieves better compression than general purpose compressors.
This technique can be used to lossless (lose no data) and
lossy (lose some data) compress sound files. And, these
compressed sound files can be decompressed and played
on-the-fly. We call this sound file type .DAS. The file
BING.DAS (included with this release) is an example of this
file type. The original sound file was Mono, 8-bit, 22Khz
and was 69999 bytes long (3.175 seconds). BING.DAS has been
compressed at loss level 2 and is only 21920 bytes long. A
compression ratio of 68% (3 to 1).

Digital Audio Sound Compressor 1.0 is distributed as
Shareware: if you like the program, please become a
registered user. See the Section "Registration Benefits" at
the end of this file for more information. Print or list the
file REGISTER.DOC for ordering information. Distribution of
this shareware program is encouraged.

Digital Audio Sound Compressor 1.0 requires an IBM PC or
compatible, and only 256K of available RAM.

The Digital Audio Sound Compressor 1.0 source code, object
code, executables and manuals on paper or on disk, are
COPYRIGHT (c) 1993 by Carole & Allen Grider.

DISCLAIMER

This program is provided "AS IS" and it is WITHOUT warranty
of any kind that it will work correctly in any or all
situations. No liability shall be assumed for direct or
consequential damage caused by the use of this software.
The only claim TAG SOFTWARE makes is that there are no
intentional bugs or fatal errors in any original copy of
the program that you receive directly from TAG SOFTWARE.

MANIFEST

DASCMP.DOC . . . . Text, Documentation (This file)
DASCMP.EXE . . . . Digital Audio Sound Compressor executable
DASEXP.EXE . . . . Digital Audio Sound Expander executable
README.DOC . . . . Text, Last minute information
BING.DAS . . . . . Digital Sound, Monty Python (Compressed)
BING.WAV . . . . . Digital Sound, Monty Python (Original)
REGISTER.DOC . . . Text, Registration order form
CATALOG.DOC . . . Text, Catalog of TAG SOFTWARE Products

DISTRIBUTION

Distribution of this program is encouraged as long as the
following Shareware principles are observed:

All of the above-mentioned 8 files should be
included in the distributed disk and should not be
altered in any way. TAG SOFTWARE authorizes the
distribution ONLY of the 8 above-mentioned files.

If archiving this program for BBS use or library use,
please include all files and use the name: DASCMP10, ( e.g.:
DASCMP10.ARC or DASCMP10.ZIP ). This will provide
consistency for future updates.

Note for Disk and Rack Vendors: Please contact TAG SOFTWARE
for the latest version of this and all our programs. Disk
and Rack Vendors are allowed to include their own
installation package. Also contact us if you require
customization. We will consider non-exclusive registration
handling agreements.

Rack Vendors: Please contact TAG SOFTWARE regarding discounts
to your customers for registering our shareware. We will
consider discounting some or all of the rack price from our
registration fee, if we receive some kind of proof-of-purchase.

SYSTEM REQUIREMENTS AND OPTIONS

COMPUTERS: IBM/PC/XT/AT or compatibles. 256K free memory.

OPERATION

Digital Audio Sound Compressor is invoked from the MSDOS command line
or batch file:

DASCMP [ -sN ] [ -e ] [ -lN ] [ -v ] in_file out_file

Options:

-sN Set speed for resultant .DAS (out_file). Overrides
value in .WAV file, if used with a .WAV file.
The default for raw files only, is 11025.

-e Use extended lossy compression mode (Averaging
Adaptive Range Compression). The default is to use
lossless compression (Adaptive Range Compression).

-lN Use lossy level N to compress in_file. Lossy
compress file to level N. N can range from 0 to 7.
Higher levels of compression may distort the sound
but improve the compression. The default is loss
level 0.

-v Display information about the sound file.

in_file is the pathname of the digital audio sound file to
be compressed. It will only be read.

out_file is the pathname of the resultant compressed sound
file. It should include a .DAS suffix.

The compression results you expect will vary. In general, a
sound sampled at 8000 Hz will generally compress at 10% to
25% lossless, some better and some worse. A sound sampled at
11000 Hz will compress at 15% to 35% lossless, again some
better and some worse. A sound sampled at 22000 Hz will
compress at 25% to 50% lossless, and again, some better and
some worse.

In general, we only use lossless compression for archiving
our sounds. The sounds we have online (and use everyday) are
compressed lossy. We play with the loss and extended
compression settings until we achieve the best compression we
can achieve with little or no loss in sound quality. In
general you will notice little change in sound quality up to
loss level 2.

Increasing the loss level (or using extended compression) up
to a point will make only small and possibly unnoticeable
changes in the sound quality. After that point, the changes
will become pronounced. These changes usually sound like
background hiss (in technical terms, increasing the loss
level increases the quantization error). However, increasing
the loss level will improve the compression.

The included example file BING.WAV is an example in point.
Lossless compression of this file yields a compression of 48%
(BING.DAS) and the file can be played or expanded back
exactly as the original. By the way, PKZIP only achieves 41%
using maximum compression. Increasing the loss level to 2
yields a compression of 68%. A difference can be heard if
this file is played with a headphone rig. But, in noisier
environments (such as where our computers are), only if one
really listens closely, will one hear the difference.
Ultimately, it is a trade-off between sound quality and disk
space. We generally choose to save as much disk space as
possible and still have good sound. We never have enough
disk space.

DASCMP 1.0 compressed files (.DAS) can be played on-the-fly
by all our sound file players (DAPLAY 2.0, DAFORT 2.0, and
DSP 1.0). Technically, the compression algorithm is a slow
to compress, fast to decompress algorithm.

Examples:

DASCMP BING.WAV BING.DAS

Compresses the windows WAVE file BING.WAV using normal
compression with loss level 0 (lossless) and produces
BING.DAS.

DASCMP -l2 BING.WAV BING.DAS

Compresses the windows WAVE file BING.WAV using normal
compression with loss level 2 and produces BING.DAS.

DASCMP -s22050 -e -l1 BING.RAW BING.DAS

Compresses the raw sound file using extended compression with
loss level 1 and produces BING.DAS.

Digital Audio Sound Expander is invoked from the
MSDOS command line or batch file:

DASEXP in_file out_file

Options:

in_file is the pathname of the DASCMP compressed digital
audio sound file to be expanded. It will only be
read.

out_file is the pathname of the resultant .WAV sound file. It
should include a .WAV suffix.

DASEXP currently only produces .WAV sound files with no
headers. This may change in future releases.

Example:

DASEXP BING.DAS BING.WAV

Expands the DASCMP 1.0 compressed file BING.DAS out to a .WAV
sound file. The results will depend on how the sound file
was compressed.

NOTES ON SOUND FILES

It seems that every sound card manufacturer has developed its
own digital audio file format. Creative Labs, being the first
with the cheapest, has prevailed with their .VOC format.
This was true until MicroSoft released Windows with the
Multi-Media Extensions. The Windows Multi-Media Extensions
uses the .WAV formatted digital audio files. Another (older)
format are the .SND files. Some seem to be MacBin format
with the original Data Fork and Information Fork information
intact. Others come from older sound packages called SOUNDER
and SoundTools. Another source of sound files are Sun/NeXT
systems with their .AU format.

Currently .VOC files are the most prevalent, with .WAV files
catching up fast. .SND files are seen here and there, but
sometimes contain really unique sounds not seen in .VOC or
.WAV format. This is very strange, because it is trivial to
convert between these various formats.

If you have trouble getting good digital audio files, see our
Digital Audio Collection Series. We have selected some of
the best audio files available and can supply them in .VOC or
.WAV format.

DOCUMENTATION AND ACKNOWLEDGEMENTS

If you have a printer, please print out and read this
documentation file DASCMP.DOC.

FUTURE ENHANCEMENTS

Currently, DASCMP 1.0 only supports Mono 8-bit sound files.
We would like to add support for Stereo 8-bit, Mono 16-bit,
and Stereo 16-bit sound files.

We would like to add support for compression of other sound
file types (.VOC, .SND, .AU, .IFF, ...). Let us know what
you want. Registered users' wants and desires get first
priority. In the interim, a program called Sound Exchange
(SOX) is the best program for converting sound file types,
and it's in the public domain (Allen is a contributer). Use
SOX to convert the sound file to a .WAV file, then use DASCMP
1.0 to compress it!

We would like to add support for expansion into other sound
file types (.VOC, .SND, .AU, .IFF, ...). But, do you really
want a program with all this baggage? SOX already provides
for this. Maybe a limited set (like just .VOC and/or .AU).
Again, in the interim, use SOX to convert the .WAV file to
the sound file type you want.

If you don't have SOX, just ask. We will send you a copy when
you register.

REGISTRATION BENEFITS

Digital Audio Sound Compressor 1.0 is distributed as
Shareware: if you like the program, please become a
registered user by sending $15 to TAG SOFTWARE. List or
print the file REGISTER.DOC for more information. List or
print the file CATALOG.DOC for a complete description of all
of TAG SOFTWARE's products.

For registering Digital Audio Sound Compressor 1.0:

- You will receive the latest registered version of this
program.

- You will receive one FREE disk from our Digital Audio
Collection Series. See the file CATALOG.DOC for details as
to which audio clips are on what disk.

- Technical Support. Please write TAG SOFTWARE. Or you
can contact us through The Programmer's Corner BBS
301-596-7692 or 410-995-6873.

As always, we will respond to your suggestions and comments.
Sometimes we can incorporate your suggestions in the latest
version of the program that you receive from us.



  3 Responses to “Category : Music and Digitized Voice
Archive   : DASCMP10.ZIP
Filename : DASCMP.DOC

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