[FFmpeg-devel] dealing with tables in DV codec
Sat Sep 13 19:13:01 CEST 2008
On Fri, Sep 12, 2008 at 07:49:23PM -0700, Roman V. Shaposhnik wrote:
> On Thu, 2008-09-11 at 12:35 +0200, Michael Niedermayer wrote:
> > > Seems like you've confused the threads, then. I fail to see the
> > > relevance of this war story to the issue at hand -- should the
> > > change that is a toss up on x86 and ~3% performance degradation
> > > on SPARC be included or not.
> > It should not be included as such, 3% speed loss is significant.
> Well, I guess we have to do something else, then. I can offer one
> solution: resurrect the DV_CODEC_TINY_TARGET, get rid of static
> tables, allocate them dynamically and not allocate them at all
> for DV_CODEC_TINY_TARGET.
Iam not sure about this, but i guess its better than what we have now, so ok.
But it should be CONFIG_SMALL not DV_CODEC_TINY_TARGET
> > > > Divx4-bugs/Lorenna_McKennit-Mummers_Dance-Mononoke_Hime-gabucino.avi
> > > > on samples.mplayerhq.hu is a good one to test idcts.
> > >
> > > Do you mean just comparing PSNRs or a more involved test?
> > i meant ffplay -idct 6 file.avi
> > and looking at it
> > for comarission you can look at
> > -idct 2 (no artifacts)
> > -idct 1 (minor atifacts)
> > -idct 4 (major artifacts)
> Are you saying I am supposed to just look at it and the problems
> will be visible?
> I'm not against it at all, but I'd rather have
> a more objective measure if I have to defend mlib ;-)
dct-test is objective, but someone alraedy posted some numbers for that
(and these number where really scary, being far outside the ranges mandates
by the specs)
> > > > Though honestly my gut feeling is that anyone knowing VIS and sparc asm
> > >
> > > Do you have anyone like that on the horizon?
> > Do you know sparc & vis asm ? :)
> I do (although my experience comes from looking at it, not
> writing it)
> -- but I'm not a maintainer of libavcodec/sparc/* ;-)
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
When you are offended at any man's fault, turn to yourself and study your
own failings. Then you will forget your anger. -- Epictetus
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