[Ffmpeg-devel] [REQUEST] MMX/MMX2 and SSE optimizations for H.264 decoding

Martin Boehme boehme
Thu Sep 15 14:06:49 CEST 2005

Reimar D?ffinger wrote:
> On Thu, Sep 15, 2005 at 01:02:22PM +0200, Martin Boehme wrote:
>>information (believe me, the guys who would be candidates for this 
>>_know_ where to get the Intel Reference Manual...).
> I guess that rules me out, I only got the AMD manuals :-P

I assume you'd know where to get the Intel manual if you needed it, 
though... ;-)

>>at libavcodec/i386/h264dsp_mmx.c). Now, I don't know if that covers all 
>>of the areas that could benefit from MMX (Michael?), but the point is: 
>>H.264 _is_ a performance-hungry codec, even for decoding, and it may 
>>just be too much for an Xbox...
> I know you can't trust it too much, but last time I checked oprofile
> indicated a lot of time is spent in some more general "parsing" and
> comparisons that can't be easily converted to e.g. MMX...
> So yes, if somebody knows a code part that could still really benefit from
> e.g. MMX please say so, because I didn't see any.

And if FFmpeg is faster than Nero, that would also seem to indicate that 
there probably isn't too much "low-hanging fruit"...


Martin B?hme
Inst. f. Neuro- and Bioinformatics
Ratzeburger Allee 160, D-23538 Luebeck
Phone: +49 451 500 5514
Fax:   +49 451 500 5502
boehme at inb.uni-luebeck.de

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