[mythtv-users] mythtv darkens dark scenes on video playback and on desktop

[Dave Richardson]

I swear this to be true (!)...

The Mythbuntu desktop and all video playback seems to darken on video
playback that involves darker scenes.  It then brightens to what I regard
as normal brightness when the scene has more color or brightness.

For instance on the plain mythbuntu desktop (Gnome?) I use a dark theme. 
If there's nothing else being displayed, the screen is darkened by, say,
40%.  If I right click to open the mouse menu, or open a menu navigation,
the whole screen brightens up again.

It's kind of like that feature (that I hate) on car stereos that raises
and lowers the audio level based upon the speed of the car.

I've disabled all power saving options on my LCD HD TV.  Is there any
chance there's a setting somewhere in mythbuntu, myth, or the nvidia
driver that I don't know about that is causing this behavior?

kit: mythbuntu 9.04, myth 0.21, ionitx a-u w/geforce 9400, nvidia driver
180 series (from their website a week ago), HDMI output.

(Cable tv playback directly into the TV does not have this "feature".

Thanks in advance!