HDMI: Image on TV too dark

[Frederik Vogelsang]

2011/10/13 Alex Deucher <alexdeucher at gmail.com>:
> The brightness is set on the TV itself.  The only thing the driver can
> really adjust is the gamma correction which is exposed via xrandr or
> xgamma if you want to adjust it.
I can turn up the brightness on the TV, but that only causes the TV's
backlight to increase. The actual dark areas stay pretty much black. I
did also already mess with xgamma but this does not improve the
situation either.

>  You might try connecting directly to
> the TV as Andy suggested, or try booting with radeon.audio=0 depending
> on how old your kernel is.
I've tried both. Neither a direct TV HDMI connection (without the AV
receiver) nor radeon.audio=0 fixed the issue.

Another strange thing: the picture quality (also with dark areas) on
Windows with the AMD Catalyst driver is also fine. I did not have to
make any brightness changes for that system, it worked out of the box
without any settings. So it has to be specific to the Linux side.

Any more ideas? Can anyone tell how the default brightness level is
set for digital outputs? Is it calculated or hard coded? What about an
xorg.conf setting?


Regards,
Frederik