[mythtv-users] Using xset to alter my TV's Black and White points?

Ben Lancaster mail at benlancaster.co.uk
Wed Dec 16 21:46:11 UTC 2009


Hi.

I've been struggling for ages with colorspace options for my TV - it's a
Sony Bravia that thinks pure black is #101010 and pure white is EBEBEB
("studio levels"?). It only does full-range RGB at its native resolution
(1368x768), but that mode won't run at anything other than 60Hz, which means
I get really bad jitter with the 25fps PAL that gets broadcast in the UK.
So, I have to stick with 720p at 50Hz and suffer black crush or white
blow-out, or shifting gamma when something "whiter than white" comes
onscreen! Unfortunately, Avenard's patches for the VDPAU colorspace stuff
seem to make little difference for me, as the real problem is when I pull
the OSD up or use the menus - sure, it adjust the video properly, but when
the OSD pops up with text at #FFFFFF, the TV shifts everything up to
compensate. Until nvidia implements a system-wide colorspace option (as they
have on Windows) I'd resigned myself to just tollerating it.

Anyway, I was just tinkering with xset to try and overcome a separate issue,
when I spotted the following in $ xset q:

Colors:
  default colormap:  0x20    BlackPixel:  0    WhitePixel:  16777215

Am I right in thinking that I could use xset's colormap stuff to compensate
for anything drawn by the windowmanager or Xorg? I'm clutching at straws
here!

Ben
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