[Phr0z]

Hi,

I hope someone can shed some light into this as it's driving me mad.

Software:
XBMC 13 Alpha7 on my Ubuntu 13.04 64-bit with kernel 3.10.7-031007-generic.

Hardware:
Intel NUC i3. Intel HD4000.
Panasonic VT60

Im trying to set my black level correctly using AVS HD 709. But using standard driver settings doesn't allow me to see bars 17-18, so I have to adjust the gamma to 1.25 with xrandr and then Im able to.

xrandr command running from script at startup.
xrandr --output HDMI1 --set "Broadcast RGB" "Limited 16:235" -r 60 --gamma 1.25:1.25:1.25 --brightness 1

/etc/X11/xorg.conf.d/20-intel.conf
Section "Device"
Identifier "Card0"
Driver "Intel"
Option "AccelMethod" "sna"
EndSection

However this only works with Adjust refresh rate to match video disabled, it seems to reset back to default settings whenever I activate it?
Is there any way to get around this?


Note1: It doesn't matter how much I increase brightness or gamma on my TV, it won't show bars 17-18.
Note2: Using same settings on my TV Im able to see bars 17-18 using my PS3 or built-in mediaplayer so Im convinced it's an driver/xbmc issue.

Thank you.

[wsnipex]

did you check if the limited range setting gets reverted when changing refresh rate?

xrandr -q --verbose will tell you.

I use practically the same command(minus the gamma) to set limited mode and it sticks during refresh rate changes.

[Phr0z]

Hi,

No, It does not change the RGB to any other mode, Limited stays when changing the refresh rate of the TV.

I did an experiment to verify it further.

xrandr -r 24

Ran the Black Levels video and let it switch to true/proper 24hz, then I changed XBMC to windowed mode and ran xgamma 1.25 and switched back to full screen.
It kept the gamma setting as long as I didn't switch to any other content than 24hz. As soon as i switched to a 60hz source movie it reverted back to 1. (for all sources 24, 50, 60)

[Phr0z]

I think my GPU registers off isnt it?

Code:

root@HTPC-Vardagsrum:/home/htpc# intel_reg_read 0x70008
0x70008 : 0xC0002000
root@HTPC-Vardagsrum:/home/htpc# intel_reg_read 0x70180
0x70180 : 0xD8004400

Limited:
intel_reg_write 0x70008 0xC0000000
intel_reg_write 0x70180 0xD8004400

Full:
intel_reg_write 0x70008 0xC4002000
intel_reg_write 0x70180 0xDA004400


Now for the interesting part:
I can't set the value intel_reg_write 0x70180 0xDA004400

Code:

root@HTPC-Vardagsrum:/home/htpc# intel_reg_write 0x70180 0xDA004400
Value before: 0xD8004400
Value after: 0xD8004400
root@HTPC-Vardagsrum:/home/htpc#

And if i set intel_reg_write 0x70008 0xC0000000 it seems to revert back to 0xC0002000 after a reboot. ?

[Phr0z]

I switched to OpenELEC

It's working fine there, so probably something related to Ubuntu 13.04 and Desktop Enviroment.

[Crssi]

Does someone know registry address for contrast?

[Phr0z]

And today I discovered if I use Full instead of Limited 16:235 I'll get my blacklevels correct using a gamma of 1 and my image won't suffer from posterization and washed out colors.

So, problem is solved, though Im not really sure what the root cause is. If it's my TV (most unlikely) or if it's actually the Intel drivers (more likely) that's outputting RGB Limited 16:235 faulty.

Anyways...

Im glad now