[Theora-dev] Directshow filters 0.64.7878

illiminable ogg at illiminable.com
Tue Oct 5 05:26:36 PDT 2004

----- Original Message ----- 
From: "Alen Ladavac" <alenl-ml at croteam.com>
To: "illiminable" <ogg at illiminable.com>
Cc: <theora-dev at xiph.org>
Sent: Tuesday, October 05, 2004 10:05 PM
Subject: Re: [Theora-dev] Directshow filters 0.64.7878

> Hi Zen,
> Great work there! The filters are getting more stable and more functional 
> in
> each revision.

Thanks... the 0.64 release is pretty good now for most people.

> Is there any chance you could also compile an version where theora 
> encoding
> is optimized in MMX, in the similar way that you did with SSE versions?

I only did the SSE/2 versions because my compiler is magic and can target 
them without the need for special instructions or intrinsics (no doubt hand 
done optimisations would get a much better speed up) :) I don't have that 
kind of spare time on my hands to optimise 100 kLOC by hand :)

There is no compiler switch to auto-generate MMX "Classic" :)

> Pretty please with sugar on top? :) Without MMX, video decoding is very
> slow. 640x480 video with sound takes about 50% CPU time of a 1.7GHz Athlon
> XP.

Doesn't that processor support SSE1 ? I thought all the athlon XP's did ?

I think there is some hand-done MMX optimisations someone did a patch for 
theora a while back... but i'm not sure how stable/correct they are or if 
they will build in VC or not.



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