r200 xvideo gamma curve

[Rene Rebe]

On Saturday 14 October 2006 19:54, 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.  If you have ideas any
> further enhancements let me know and we can discsuss the hardware
> capabilities in detail.

Disclaimer: I have no SPEC as well.

Maybe the effect occurs when someone has xgamma of e.g. 1.8 and the xvideo 
gamma is always fixed to 1.0 (that is the xvideo overlay gamma is independant 
of the non-overlay gamma LUT)? Maybe both LUT should be kept in sync in that 
case?

Yours,

-- 
  René Rebe - ExactCODE - Berlin (Europe / Germany)
  http://exactcode.de | http://t2-project.org | http://rene.rebe.name
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