[net.micro.amiga] IFF Dpaint format

McFarland.henr@Xerox.COM (03/12/86)

From: McFarland.henr@Xerox.COM




I'm working on a project that requires some pretty pictures, so we've
decided to use DPaint as a graphics tool. So far, I've spent the last
couple of evenings investigating the structure of DPaint IFF files,
locating the CMAP, GRAB, CRNG etc. structures, as well as what I suspect
is the designator for graphics files called ILBMBMHD, and the bitmap
data in the BODY subrecord.

In the ILBMBMHD subrecord, in addition to the bitmap width and height,
and what appears to be fixed data, I've noticed a compression flag and a
few other bytes of formatting information. Further investigation shows
that scan line planes are run length encoded, and proceed until a run
length of zero is reached. At this point, the compression algorithm
seems to change, and I've not been able to decode it yet. 

Does anyone know what the compression flags are, and what the algorithm
is ?

	Thanks in advance

		Doug McFarland

     

McFarland.henr@Xerox.COM (03/12/86)

From: McFarland.henr@Xerox.COM



I'm working on a project that requires some pretty pictures, so we've
decided to use DPaint as a graphics tool. So far, I've spent the last
couple of evenings investigating the structure of DPaint IFF files,
locating the CMAP, GRAB, CRNG etc. structures, as well as what I suspect
is the designator for graphics files called ILBMBMHD, and the bitmap
data in the BODY subrecord.

In the ILBMBMHD subrecord, in addition to the bitmap width and height,
and what appears to be fixed data, I've noticed a compression flag and a
few other bytes of formatting information. Further investigation shows
that scan line planes are run length encoded, and proceed until a run
length of zero is reached. At this point, the compression algorithm
seems to change, and I've not been able to decode it yet. 

Does anyone know what the compression flags are, and what the algorithm
is ?

	Thanks in advance

		Doug McFarland

     

page@ulowell.UUCP (Bob Page) (03/18/86)

In article <1520@caip.RUTGERS.EDU> McFarland.henr@Xerox.COM writes:
>I'm working on a project that requires some pretty pictures, so we've
>decided to use DPaint as a graphics tool.

Why not use Aegis Images?  It won't trash your disk.  I have used
Graphicraft, DPaint, Images and all the PD draw programs, plus MacWrite
and anything else I could paint with, on just about any micro.  Images
takes the cake.  Except for two things.  One is that you can't bend
brushes like DPaint can.  The other is that it is compiled under
Aztec C, so the executable is just three hunks ... text, data and bss.
If you have severe memory fragmentation, Images may not load.  Once
you have it up, though, it has so many good things it can do that
DPaint can't.  Check out Animator to make those pretty pictures move.

>                                            So far, I've spent the last
>couple of evenings investigating the structure of DPaint IFF files,
>locating the CMAP, GRAB, CRNG etc. structures, as well as what I suspect
>is the designator for graphics files called ILBMBMHD, and the bitmap
>data in the BODY subrecord.

Make sure you are looking at the current rev of the IFF spec, which have
been published *since* the V1.1 RKM was printed.  They include:
	FTXT: Nov 15 (Formatted TeXT) (Draft 2.6)
	ILBM: Jan 17 (InterLeaved BitMap)
	8SVX: Feb  7 (8-bit Sampled Voice)
	SMUS: Feb  5 (Simple MUsical Score)
Note that 8SVX and SMUS are new IFF items not included in the RKM.

Because I now expect a flood of requests for the new IFF documents,
I will post them.  DON'T ASK ME ABOUT IFF because I have not read
the specs yet ... I just have them, since I hope to use them once
ZLI is done (another saga).

>Does anyone know what the compression flags are, and what the algorithm
>is ?

Not my ball game.  Aren't the sources in the PD too?  I'll hunt around...

>	Thanks in advance -

Anything to help the cause!

..Bob

PS I don't work for anybody mentioned above, except the Organization: line.



-- 
UUCP: wanginst!ulowell!page	Bob Page
ARPA: page@ulowell.CSNET 	U of Lowell CS Dept
VOX:  +1 617 452 5000 x2233	Lowell MA 01854 USA

ridder%warlok.DEC@decwrl.DEC.COM (04/02/86)

From: ridder%warlok.DEC@decwrl.DEC.COM  (Hans)


Date: 24 Mar 1986 1137-MST
From: Hans <RIDDER at WARLOK>
To: "info-amiga@red.rutgers.edu" at DECWRL
Subject: RE: IFF Dpaint format
Message-ID: <"MS10(2137)+GLXLIB5(0)" 12193307290.28.143.183689 at WARLOK.TCP>
Regarding: Message from Bob Page <"ulowell!page@caip.rutgers.edu" at DECWRL>
              of 23-Mar-86 2356-MST
 
Thanks to Bob for answering the IFF questions.  Is there a place where
I can get a machine readable copy of the complete specification?  (on
the ARPA side of the gateway).  An address to get a hardcopy would do
too. (and the price!)
 
I gather that some version of IFF is documented in the RKM, but I'm
one of those lucky souls who got the BIG card instead of a manual
with my manual set!  (I wish the folks at C-A would forward some
of our complaints to the "manual department"....  It's been over two
months!)
 
-hans
   --------