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ILBM-Packer1,0.doc
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1993-08-06
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ILBM-Packer V1.0 (c) by Alexander Wegner June 17.August.93
Introduction
------------
This program is shareware. It may be distributed freely, if you follow
these three rules:
1. The executable must be distributed with this .doc file, and the german
.dok file.
2. All files must be unmodified.
3. Copies should not be sold. A fee for disks and copying which may not be
higher than 6 US$ is allowed.
If you use this program please send a shareware fee of 5 US$ or 8 DM.
Everyone who pays this shareware fee will be informed when a new version
is ready. If you send 10 US$ or 16 DM (12 US$ for oversea) I'll send you a
new version on disk when it's ready.
Please make payments in US$ only with banknotes. If you pay in DM you can
(must) use coins.
If you want to use this program in commercial products please ask me for
permission.
Send money, remarks, bug reports to the adress below.
**************************************************************************
* Please note: The author is not responsable for any damages caused by *
* this program. *
**************************************************************************
What is ILBM-Packer
-------------------
One of the advantages of our favourite machine is the IFF/ILBM (Interchange
File Format / InterLeaved BitMap) format which is used by nearly every graphic-
program. But everybody knows that computer-graphics need a lot of disc-space,
expecially if you use the HAM (Hold And Modify) mode.
Its also difficult to compress ILBM-files with an ordinary file packer. There
are two reasons for this fact:
1. Most of the ILBM- files are compressed with the byterun1 algorithm,
which is a part of the ILBM standart and is used by many graphic-tools.
This algorithm works quite fast, but it's only effective if there are
bigger areas in the same color in your picture.
2. Pics that are created with a ray-tracer or which are video-digitized and/or
dithered are quite "chaotic", because there usually aren't bigger areas in the
same color or pattern.
ILBM-Packer is a file packer which is specialized in ILBM-Files. You cannot
use it on any other files. ILBM-Packer uses an algorithm which reads the
bitmap-header and considers the graphic-mode (size, num. colors...).
Therefore it's more effective than ordinary packers.
The program is written in assembler which makes it working quite fast.
How to use ILBM-Packer
----------------------
The usage of this tool is quite simple. The best way is to copy it into
your c directory, because it's used from the shell or cli. You have to type
the following: ILBMP <sourcefile> <targetfile> . The sourcefile will be
loaded, crunched and saved under the name and path specified as targetfile.
If (for example) your currend dir is "df0:diashow" and you type:
ILBMP monalisa.pic dh0:pics/monalisa.cbm
A file called monalisa.pic is loaded from the drawer df0:diashow and saved
as a crunched file under the name "monalisa.cbm" in the dir dh0:pics. It's
advised to use extensions like ".cbm (crunched bit map) or what ever you
want, because it's easyer to see whether a file is compressed or not.
ILBM-Packer will open a window to display informations. You will see the
name of the sourcefile, its lenght in bytes, x and y size of the graphic,
the number of bitplanes and the actual compression of the sourcefile. The
value after "compress." can be "none" or "byterun1" that will mean, that
the file is uncompressed or the byterun1 algorithm is used. After the
sourcefile is loaded and byterun1 is decrunched (if needed) the file will
be compressed in two passes. If the compression was succesful the lenght of
the new file will be displayed in bytes and in percent and the new file
will be saved.
If you want to decrunch a file you have to do the same. The file that
should be decrunched must be specified as sourcefile. The actual
compression is ILBMP. Decrunching starts with Pass 2 (last in first out).
If the byterun1 algorithm was used in the original file the decrunched file
will be bigger than the original, because the files are not recrunched with
byterun1 by the packer. To bring the file to its original size, you have to
load and save it whith a graphic-tool that supports byterun1 (D-Paint for
example).
Sourcefile and targetfile can be the same. In this case the sourcefile is
overwritten with the packed one. This can be dangerous, because errors while
owerwriting the file can destroy both (source and targetfile). So make a
copy of the sourcefile before overwriting it.
How to use the ILBM-Packer in script-files
------------------------------------------
This tool hasn't got an internal script-function, but it can be used in
script-files without problems. At this point i've got a special hint for
you: If you have, for example, a dir named "dh0:pics" with 20 ILBM-files
in it, and you want them to be crunched and saved with a ".cbm" extension
in "dh0:archive", you have to type the following into your CLI-window:
'list dh0:pics lformat="ilbmp %s%s dh0:archive/%s.cbm" to ram:script'
This command will create a fit script-file, which can be executed by
typing: 'execute ram:script'.
Possible problems and solutions
-------------------------------
bad arguments (return code 10):
Bad command line. Sourefile and targetfile were not specified properly.
not an ILBM-file (return code 10):
The sourcefile has not been recognized as an ILBM-file. Check the filename!
file not found (return code 10):
ILBM-Packer couldn't open your sourcefile. Check path and currend dir!
out of memory (return code 20):
Not enough or fragmented memory. Reboot your machine (to avoid
fragmentation), remove disk buffers, clear RAM: and RAD:, close all other
tasks and try again.
file has not been compressed (return code 5):
I hope you'll not see this very often. This can happen if your file is very
chaotic or has less than 3 bitplanes (less than 8 colours). The algorithm
does not work very good on files with 1 or 2 bitplanes.
disk error while writing targetfile (return code 20):
This could be "read write error" or "disk is full" or any other reason, why
the targetfile has not been written properly if you had a "disk is full"
requester you must delete the targetfile, because it's truncated.
software error guru meditation... (return code ?)
There are many reasons for that. One of them could be a truncated
sourcefile. Be sure, that your sourcefiles are okay.
Compatibility
-------------
ILBM-Packer has been tested on the following hardware: A2000 rev4; rev6;
kick 1.3 and 2.0 (both on roms); RLL and SCSI harddisks; 68030 turboboard
Incompatibility
---------------
ILBMP does not work correctly with the stencil function of DPaint. There
may be problems with other "special functions" like that.
ILBM-Packer and the new graphicmodes
------------------------------------
I don't know if ILBMP is compatible to the new A1200 A4000 graphicmodes,
because I didn't have the chance to test it on such a machine
My adress
---------
Please send money, comments, bug reports ... to:
Alexander Wegner
Mackensenstraße 5
42329 Wuppertal
Germany
************************************************
* // *
* \\ // greetings to all users in the world *
* \X/ *
************************************************