[mythtv-users] Really washed out picture since upgrade to 0.24.0

Andre mythtv-list at dinkum.org.uk
Sun Nov 21 15:55:28 UTC 2010


On 21 Nov 2010, at 05:35, Kevin Johnson wrote:

> I have had some issues with this also.  Since the new nvidia drivers, I noticed some things work opposite of what I think they should.
> My panny plasma will not do full range.  So with .23 I used the vdpaustudio with good results.
> Now with .24 I have tried several different options to try and get the blacks correct.
> I tried removing the vdpaustudio option in mythtv and using rgb limited in nvidia-settings.  This resulted in the blacks still being slightly crushed.
> Then I tried setting the nvidia driver to full range and using vdpau studio in mythtv.  That made everything look grey.
> Ultimately, I get the correct blacks by setting nvidia to rgb limited, and using vdpaustudio in myth.
> Nothing seems to work exactly like you would think it would.

This is what I found on my display (Optoma HD80 1080p DLP projector) which only works correctly with studio (restricted) levels. I checked this using a recording of the BBC HD testcard.

The Nvidia-setting YUV, RGB, RGB restricted has no effect on the levels as seen in a VDPAU rendered mythtv recording playback. Default is full range PC levels which crushes blacks and whites on my display.

When the vdpaustudio setting is applied to mythtv "correct" studio or restricted levels are seen. Full range blacks and whites, anti crushing spots are visible in the black and the white boxes of the test card.

Nvidia-settings when set to YUV or RGB restricted gives a better looking theme, I use Arclight and it looks very very black with full range RGB. With restricted RGB or YUV the subtle graduations in the theme are apparent, text antialiasing looks much smoother, overall much better looking.

With my display I see better detail and less (no) colouration in shadows when running nvidia-settings in YUV.  I can only attribute this to my display handling YUV better than RGB or to VDAPU (or Myth) goes through less (or no) conversions when the frame buffer is running in YUV mode.

Best settings for me are therefore YUV in nvidia-settings and vdpaustudio in myth TV playback settings.

Andre


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