01-20-2020 03:22 AM
Hi, i'm trying to enable graphics for a Zynq MPsoc.
I have live video in YcbCr and live output in YCbCr. Graphics will be RGB. I enabled the converter inside DP.
In linux my application run Xorg, it modifies the output bringing back RGB output. I can't see any graphics.
I read in the driver page
that 12 bit YUV formats are not supported.
What doues this mean? that i cannot use output as YCbCr from DP when using linux?
That would make sense considering that i don' see the graphics.
Since i need an SDI video chain, i should then configure the DP to work in RGB and do the 444:422 RGB YCbCr outside right?
01-20-2020 05:40 AM
The page only mentions that 12-bits YUV is not supported. But this still means that 6/8/and 10-bits YCbCr are supported.
Do you get any output with RGB?
Once again, you are in an unsupported usecase (using the live output without the PHY) so I am not sure what will be the behaviour of the driver
01-24-2020 04:54 AM
Hi @florentw ,
i make the graphics work with RGB, the problem was the xorg.conf config because the timing it uses must be the same of SDI (in my case for 1280x720@50Hz), not the timing for display port (DMT timing if i'm not wrong).
Anyway displayport live output is always 12 bits per component RGB or YCbCr(from the manual), if i configure everything rgb i have no problem (so live input, graphics and live output).
If i set llive video to YCbCr, when linux starts it reconfigures the output and i see wrong colors. So i would like to know if this is expected and if there is a gentle way to tell linux (or Xorg) that i use YCbCr. As an alternative, i'm thinking about configure the DP output after linux load overwriting the linux behaviour
02-11-2020 03:34 AM
Sorry about the delay on this. Were you able to make any progress and find how to set the color space in linux?
02-11-2020 11:47 PM
i haven't tried yet, i was looking at thr device driver bindings, the old specifies the color space, maybe i can specify it also with the new.
02-12-2020 01:18 AM
You will be able to change what clolor space you say you support, so setting YUV422 only might be a solution.
But I guess there should be another solution from linux side to set the default. But I do not have enough knowledge on linux for that...
Would you know how to set the default color space used by xorg for the displayport controller?