r200 xvideo gamma curve

[Rene Rebe]

On Sunday 15 October 2006 01:31, Edgar Toernig wrote:
> Alex Deucher wrote:
> > On 10/14/06, Edgar Toernig <froese at gmx.de> wrote:
> > > Hi,
> > >
> > > I wasn't satisfied with the quality of the xvideo overlay.
> > > Dark areas had a very low color resolution giving large
> > > patches of the same color without any details.  At 6.9
> > > release time a looked at radeon_video and noticed that
> > > the gamma curve seems to be non-linear at gamma 1.0.  I
> > > changed it[1] and IMO the picture is much better now - dark
> > > areas have much more details.
> > >
> > > Is the gamma curve supposed to be non-linear or is it just
> > > some kind of "make dark areas black" hack?
> >
> > The values for the various gamma setting were given to me by ati.  As
> > you can see the entire curve can be adjusted, I just picked the preset
> > values ati offers in their windows driver.  If your changes make a
> > good improvement, I'm happy to apply the patch.
>
> I changed the values when I noticed, that mplayer output looked
> much better when using -vo x11 instead of -vo xv.  With the
> patched gamma settings, I can no longer see a difference between
> the two.
>
> > If you have ideas any further enhancements let me know and we
> > can discsuss the hardware capabilities in detail.
>
> Well, somehow the other gamma settings look kind of broken - they
> produce major color artifacts.  Is it possible that there are
> some arithmetic overflows during the conversion?
>
> Ciao, ET.
>
> PS: As I've found no tool to set Xvideo attributes, I've written a
> small cmd-line tool to query and change the settings.  If someone's
> interested ...

http://www.t2-project.org/packages/xvattr.html

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  René Rebe - ExactCODE - Berlin (Europe / Germany)
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