ATI oss color space compressed in the dark shades of gray

Sebastian Schultz sebastian2.schultz at st.ovgu.de
Sun Mar 16 15:02:52 PDT 2014


Thanks for the replies, Alex.

I really appreciate all the good hints, but I'm to afraid of messing things up 
because I do not really get what's done in those few lines of code.

I'm just curious after looking into the code: is everyone using a these 
drivers and having some display connected to his/her hdmi port affected? And 
would therefore every ati user possibly benefit from this feature? Or is my 
case just a corner case of hardware not following specs (or somehitng like 
that)?

I hope someone will find some time to get to this new feature soon. Thanks for 
all the good work you guys are doing, I'm really impressed with what has 
changed since I last tried the free drivers!

Sebastian


Am Freitag, 14. März 2014, 15:42:56 schrieb Alex Deucher:
> On Fri, Mar 14, 2014 at 9:26 AM, Alex Deucher <alexdeucher at gmail.com> wrote:
> > On Thu, Mar 13, 2014 at 6:34 AM, Sebastian Schultz
> > 
> > <sebastian2.schultz at st.ovgu.de> wrote:
> >> Is there anything I can do to about it? Or is this an upcoming feature?
> >> Or is it a bug and I should submit a report?
> > 
> > It would be a new feature.  It's not a high priority at the moment, so
> > I'm not sure how quickly we would get to it.
> 
> If you are inclined to play with this yourself, try adjusting the
> registers in dce5_crtc_load_lut(), in particular
> NI_OUTPUT_CSC_CONTROL.NI_OUTPUT_CSC_GRPH_MODE.  Try setting it to
> NI_OUTPUT_CSC_TV_RGB or NI_OUTPUT_CSC_YCBCR_601 or
> NI_OUTPUT_CSC_YCBCR_709.
> 
> Alex
> 
> > Alex
> > 
> >> Sebastian
> >> 
> >> Am Mittwoch, 12. März 2014, 12:18:37 schrieb Alex Deucher:
> >>> On Wed, Mar 12, 2014 at 10:31 AM, Sebastian Schultz
> >>> 
> >>> <sebastian2.schultz at st.ovgu.de> wrote:
> >>> > Hello,
> >>> > 
> >>> > first of all: I'm using a Radeon 7750 in combination with a monitor
> >>> > via
> >>> > display port and a tv via the HDMI port. Most of the time I do not
> >>> > want a
> >>> > picture on the tv, only when wathcing videos, so I use xrandr scripts
> >>> > to
> >>> > switch that display on and off. And here comes my problem:
> >>> > 
> >>> > With the arrival of linux 3.13 to the [core]-repo of arch linux I
> >>> > switched
> >>> > from catalyst to the open source drivers, as they finally provide a
> >>> > sufficient performance. My only problem now is that the colorspace is
> >>> > compressed for gray values below 16 (that means every shade of gray
> >>> > having values of 0 to 16 look just black). That's only the case for my
> >>> > HDMI-output connected to my TV, which worked without problems with the
> >>> > catalyst drivers. Also, only the dark grays are compressed, the
> >>> > near-white grays show up correct.  My Xorg.0.log shows that the TV on
> >>> > HDMI-0 supports the RGB 4:4:4 encoding (just like the monitor does):
> >>> > http://pastebin.com/PF6sjzu1
> >>> > 
> >>> > I found a xrandr-command "--set "Broadcast RGB" "Full"", which can be
> >>> > used
> >>> > with chips from Intel. Is there something similar for the open source
> >>> > ati
> >>> > drivers?
> >>> 
> >>> Not at the moment.
> >>> 
> >>> Alex
> >> 
> >> _______________________________________________
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