[Ffmpeg-devel] really slow decoding of huffyuv-encoded video

Thoralf Schulze thoralf_schulze
Mon Jan 22 17:25:43 CET 2007


hi there,

cpu usage is going through the roof when ffmpeg
decodes huffyuv-encoded video. 
just did a quick test with ffplay: decoding a
huffyuv-video consumes about 18% cpu time, whereas the
very same video encoded with mpeg4 (xvid) only takes
4%. 320x240 in both cases, p4/2.53ghz. this strikes me
as being odd, since xvid is usually far more demanding
than huffyuv in terms of computing power.

the ffmpeg version i used is the current gentoo-ebuild
(dated 2006-10-16).
During the configure run, an "optimize  no"-message
flashes by, which I'm a bit unsure about: does it say
that ffmpeg gets no optimisations at all or does it
refer to ffmpeg not being optimised for size?
Additionally, gcc throws a lot of warning about not
being able to inline code during the make run. See
http://forums.gentoo.org/viewtopic-t-533766.html for
details.

It would be really cool if someone could shed some
light on this issue ... is the slow decoding of
huffyuvs due to the missing optimisations, or is there
another reason?

thank you very much,
thoralf.


	
	
		
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