[comp.graphics] IFF, RIFF

jonabbey@cs.utexas.edu (Jonathan David Abbey) (03/02/91)

I understand that RIFF is based on the IFF file format.  Could anyone explain
to me how they differ?  I.E., why was RIFF not made to be compatible with
the IFF file format, even if not compatible with IFF-ILBM?

I understand that either MacroMind or Microsoft is using a multimedia file
format based on IFF.  Is this RIFF?  If not, how compatible is it with the
IFF file format?

Finally, I know that Autodesk Animator was written by the author of Aegis
Animator on the Amiga and Atari ST, who was one of the original developers
involved in the IFF-ANIM standard.  Are GL files based on IFF file structure?

Information on any other IFF derivatives are welcome.


-- 
-------------------------------------------------------------------------------
Jonathan David Abbey              \"I am stronger than the passing time" -Frost 
the university of texas at austin  \  jonabbey@cs.utexas.edu  "Does any of this
computer science/math?/psychology?  \ (512) 472-2052           make sense?" -Me 

kdarling@hobbes.ncsu.edu (Kevin Darling) (03/02/91)

jonabbey@cs.utexas.edu (Jonathan David Abbey) writes:
>I understand that RIFF is based on the IFF file format.  Could anyone explain
>to me how they differ?  I.E., why was RIFF not made to be compatible with
>the IFF file format, even if not compatible with IFF-ILBM?

This is from a quick look, and may not be wholly correct...

Basically, they're very similar, except:  they start with "RIFF" instead of
"FORM", uppercase chunk names are globally defined and must be registered,
lowercase chunk names are meaningful only locally within a chunk (nice!),
and of course, Intel byte ordering is used throughout (which is just
plain dumb for an interchange format, to me).

And of course, all the chunk names and meanings are new.

>I understand that either MacroMind or Microsoft is using a multimedia file
>format based on IFF.  Is this RIFF?

Yes, the Microsoft/IBM format is RIFF.  Not sure about MacroMind.

>Finally, I know that Autodesk Animator was written by the author of Aegis
>Animator on the Amiga and Atari ST, who was one of the original developers
>involved in the IFF-ANIM standard.  Are GL files based on IFF file structure?

You mean Jim Kent?  I've never seen a "GL" file.  The FLI Animator files
are NOT IFF-based, but similar in arrangement... and easy to decode.

>Information on any other IFF derivatives are welcome.

There are lots of actual IFF chunks out there.  We're currently using
CD-I IFF chunks on a computer we're working on, because of the chunky
pixel storage method (vs InterLeavedBitMap).
  regards - kevin <kdarling@catt.ncsu.edu>