[geeks] Wooh - Mac OS X.2

Joshua D Boyd jdboyd at cs.millersville.edu
Fri Jul 19 00:54:43 CDT 2002


On Fri, Jul 19, 2002 at 12:36:21AM -0500, Jonathan C. Patschke wrote:
> > I'm the guy who would really be pushing the video and disk systems of
> > any machine I purchase.  I stream video through GL textures.
> 
> This has been a "neat hack" under IRIX since the Indy days.  It's doable
> on any machine that supports video I/O and hardware texture-mapping.

Yes, but it still stresses things if you are processing the video in
the GL system (say via OpenGL Imaging), and also doing dual streams.
But, if you do it write, you get dual stream realtime video editing
with out fancy add on cards.  And if you disks subsystem is up to
snuff, then on irix it pretty much just works.  Other platforms
(windows, linux, and reportedly mac) require much more effort to pull
it off.
 
> > Turn pictures to colored vertexs,
> 
> That seems more CPU-bound than gfx-bound, if I'm understanding that
> correctly.

Mainly CPU, probably.  But, it also creates a fair number of
vertices.  I don't do it often.  I'd been fiddling with a video
playback system that would be hardware accelerated on systems that
didn't support hardware texturing.  GL zoom is still accelerated
usually though, so it's not like it was really a needed system.
 
> > load 30 megs models and want to work on the interactively.  I apply
> > linear algebra in strange ways to colors, and want all of it in
> > realtime.
> 
> Realtime is what you make of it.  I have no idea how well Aqua (or
> whatever it is on OSX that actually drives the UI and event system) holds
> up to moving that much data around.
> 
> That said, if you just need an assload of gfx memory to hold your
> geometry, a GeForce 4MX is cheaper than a IR2 gfx cardset.

The best system I worked with for doing that was a RE2 graphics
setup.  Almost as good was a wildcat 4000.  MaxImpact was seriously
slow, but not anywhere near as bad as TNT2s were.  But, Geforce4s
weren't out at the time.  Things always change.  SGI video hardware is
better well rounded, but Macs have huge amounts of 3d power cheap.  
 
> > I want my own inferno[1] on a budget.  I want to quickly prototype
> > ideas, then combine them together into larger usefull programs.
> 
> You're probably going to want good OOP support.  IRIX has this in C++.
> OSX has this in Objective C.  I don't particularly like either of them,
> but Java3D has been way too slow for me in the past.

Java is right out in my book.  Under Irix, things depend a lot on the
toolkit.  After much usage, I'm not as thrilled as I once was with
GTK.  Doing things from scratch is possible (and time honored).  From
what a friend has shown me, Carbon looks like a dream for bringing
together complex systems.  But, I don't actually know Objective C.
 
> > Well for starters, good video apis.  dmedia seems OK, but from I've
> > seen quicktime and the carbon classes are far nicer.
> 
> Have you looked at that class-library that abstracts over dmedia (can't
> think of its name right now)?

Are you thinking of OpenML?  If so, I haven't seen what's really up
with it.
 
> > All the pieces are available for free.  But the idea is to save time
> > so I can focus on the cool stuff, not on adding one more picture or
> > video codec to my program.
> 
> Certainly.  If you want lots and lots of video with a transparent codec
> interface, you probably want Quicktime, or Video for Windows, but I'm
> guessing that you're Not Going There.

Quicktime would be acceptable if I ended up with a Mac.  Windows
wouldn't be.  I'm not totally against writing my own codec.  I want to
load more images that just tiffs and targas.  I'll probably limit
video to only one format long time.  At the moment (most work being on
a linux machien), I'm leaning towards quicktime.  
 
> > I could use a second processor for processing the next frame of video
> > while the first one finishs up the current frame.
> 
> I know this is probably what you mean, but try to think of this in terms
> of threads, as opposed to in terms of CPUs (that is, let the OS handle CPU
> affinity).  There's a possibility that Apple might go beyond 2 CPUs
> sometime this century.

True.  I was trying to be dramatic.  It's too late at night for me to
be attempting anything fancy though.
 
> > But increasingly I want an Octane, and the cost of video IO on it is
> > just so so high.
> 
> s/video/any auxilliary/
> 
> SGI make great hardware, but this would be the pain of vendor-specific
> buses.

In the end, what I get will probably be what I feel like when I get
the money.  As you say any auxillary will be expensive.  But, if I
really want the Octane, I can just drop a linux box next to it for
capture and playback.  Or, maybe someone will eventually support one
of the affordable PCI cards in an Octane.  I've heard rumors that one
of the vendors of MacOS SDI cards was thinking of adding Irix and
Solaris support.  I wish I could remeber which one.

-- 
Joshua D. Boyd



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