[((( atom )))]

Yep, absolutely no differenc when playing video. Difference clearly visible in the GUI.
Playing a ramp of black levels 2-25 I can see all of them flashing when I turn up the brightness.
Commands are:
DISPLAY=:0 xrandr --output DP1 --set "Broadcast RGB" "Limited 16:235"
DISPLAY=:0 xrandr --output DP1 --set "Broadcast RGB" "Full"
DISPLAY=:0 xrandr --output DP1 --set "Broadcast RGB" "Limited 16:235"
DISPLAY=:0 xrandr --output DP1 --set "Broadcast RGB" "Full"

Lemme get the logs...

yaourt -Ss mesa | grep installed | pastebinit
http://pastebin.com/iqppdjYz

DISPLAY=:0 vainfo | pastebinit
libva info: VA-API version 0.39.4
libva info: va_getDriverName() returns 0
libva info: Trying to open /usr/lib/dri/i965_drv_video.so
libva info: Found init function __vaDriverInit_0_39
libva info: va_openDriver() returns 0
http://pastebin.com/UzLFAvcJ

..ouch! - guess I might need that one?

cat ~/.kodi/temp/kodi.log | pastebinit
http://pastebin.com/8YHnD37M

dmesg | pastebinit
http://pastebin.com/GVAEMPhz

id | pastebinit
http://pastebin.com/354RdyWJ

and since there is no amixer:
jack_lsp -tcp | pastebinit
http://pastebin.com/X8PbF8rP

Will go and get me a bottle of wine now, I won't be long...