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

Michel Bardiaux mbardiaux
Mon Jan 22 17:37:44 CET 2007

Thoralf Schulze wrote:
> 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).

Then the problem should be reported to the gentoo package maintainer, 
not here. Only the latest svn is supported here (not here, actually, on 

> 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.

Michel Bardiaux
R&D Director
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