[gst-devel] Configuration (fwd)

Erik Walthinsen omega at cse.ogi.edu
Tue Feb 1 08:50:49 CET 2000

Um, I'm going change the list setup so the list doesn't automatically get
stripped from the to: line on replies.  Everyone here is grown up enough
to clean up headers before they send, I hope ;-)

---------- Forwarded message ----------
Date: Mon, 31 Jan 2000 23:48:06 -0800 (PST)
From: Erik Walthinsen <omega at cse.ogi.edu>
To: Wim Taymans <wim.taymans at tvd.be>
Subject: Re: [gst-devel] Configuration

On Tue, 1 Feb 2000, Wim Taymans wrote:

> We need to clean this up. I would prefer one binary with MMX support
> activated when the processor is capable. This is always good from the
> distributers perspective. 
Agreed.  Check the design of getbits.c.

> I checked in a mmx.h, removing the dependency for libmmx. I think we
> should rename HAVE_LIBMMX to something like USE_MMX or so.
With mmx.h in include/, yes, we should remove that.  Not sure if USE_MMX
makes sense, if we're going to build a binary with it anyway.  I also
can't see anyone trying to build this on an x86 machine with a compiler
that didn't understand MMX (besides, I think mmx.h uses opcodes instead
of inline-asm).

> Maybe we should set a global flag (or have a method) to query the
> MMX capabilities of the CPU. All codecs could then set the pointers
> to their different functions as needed.
Yup.  Wonder how that could be done generically, maybe part of gstutil.c
with a global _gst_processor_caps struct and query functions?

> init() {
>   if (get_cpu_capabilities() & CPU_MMX)
>      somefunction = somefunction_MMX;
>   else
>      somefunction = somefunction_C;
> }
Precisely what I do in getbits.c ;-)

         Erik Walthinsen <omega at cse.ogi.edu> - Staff Programmer @ OGI
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