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Is there a way I can adjust contrast/brightness of the card (VGA) output when using the open source xorg radeon driver? I have a monitor that has poor image quality when its tweaked using it's knobs, and the only way I can get good image is to tweak it from the graphic card. I was using the proprietary fglrx until now, but i want to switch to radeon.

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up vote 2 down vote accepted

Using xcalib:

$ xcalib --contrast [percentage] -- alter
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If xcalib/xgamma do not apply settings to all or a specific monitor in a multiple monitor setup configured dynamically via xrandr, then brightness and gamma per-output can be controlled via xrandr:

xrandr --output DVI-0 --brightness 0.8 --gamma 1:1:1
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⁺¹ for it is also default software that is generally shipped with X. – Hi-Angel Oct 15 '14 at 5:15
$ xcalib -d :0 -s 0 -brightness 10 -contrast 100 -alter

$ xcalib -d :0 -s 0 clear

That's what I need to do to watch hulu with the radeon driver. Previously with amdcccle I had to up the top slider to 1.45 instead of 1.0 for roughly the same brightness so the shows are not so dark. An HD4550 in my case. And recently switched given that the latest (6 months old) ati legacy driver works on 3.4 or older kernels, and debian sid runs a 3.9 version at the moment.

Surprisingly 3D support on this legacy model seems on par with the proprietary driver with the radeon driver. Although re-installing the non-proprietary parts was a bit of a pain to undo the proprietary changes. Pros and cons as I wont have to re-install the proprietary driver every time there's a new kernel or mesa3d (libGL) update from this point forward.

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