[XviD-devel] More MMX improvements

[carlo.bramix]

Hello,
thanks a lot for your replies.
Unfortunately, I thought those routines were speed critical for the fact they were rewritten in ASM.
I will try to do improvements on other parts of the codec.

Sincerely,

Carlo Bramini

---------- Initial Header -----------

>From      : xvid-devel-bounces at xvid.org
To          : xvid-devel at xvid.org
Cc          : 
Date      : Fri, 29 Jul 2005 00:18:03 +0200
Subject : Re: [XviD-devel] More MMX improvements







> Hi all,
> 
> Quoting Pascal Massimino <skal at planet-d.net>:
> 
> > 
> > 	Howdy everybody,
> > 
> > On Thu, 2005-07-28 at 22:38, Guillaume POIRIER wrote:
> > > Hi,
> > > 
> > > On 7/17/05, carlo.bramix <carlo.bramix at libero.it> wrote:
> > > > Hello,
> > > > I did more improvements to:
> > > > 
> > > > \xvid_20050712\xvidcore\src\bitstream\x86_asm\cbp_mmx.c
> > > > 
> > > > This new version is 6.2% to 7.4% faster if compared to the same source
> > into the CVS.
> > > > I attached this new patch here.
> > > 
> > > Your optimization do work for me, but I can't measure any speed-up.
> > > You must be optimizing a part of XviD that doesn't account for a large
> > > part of the encoding process.
> > > 
> > > Now, I don't know what the maintainers are gonna do about it, but I'm
> > > quite worried about the fact that no one has commented on that patch.
> > > :-(
> > 
> > 	It's on my to-commit list ... when holidays are over :)
> > 	Anyway, it's normal and expected you don't see any
> > 	speed-up. Cbp calculation is called once per MB. Would
> > 	it not be in MMX/SSE, but simply plain C, you wouldn't
> > 	notice the difference either. 
> > 	*But*, i personally find it very pleasant lot of people
> > 	try to optimize this particular function. 
> 
> Yes, the reason why not many commented on this optimization (besides the
> fact that it's holiday season) is probably that no noticable overall speed-
> up can be expected from this patch. As Skal pointed out, the cbp calculation 
> code is actually not really speed critical, which however didn't prevent
> people from writing many optimizations for it - but that's perfectly fine
> and just demonstrates the huge motivation of people to participate in
> development...
> 
> Michael
> 
> _______________________________________________
> XviD-devel mailing list
> XviD-devel at xvid.org
> http://list.xvid.org/mailman/listinfo/xvid-devel
> 



____________________________________________________________
6X velocizzare la tua navigazione a 56k? 6X Web Accelerator di Libero!
Scaricalo su INTERNET GRATIS 6X http://www.libero.it