Kodi Community Forum

Hi guys!

I had to downgrade my AMD Windows graphics drivers to a previous version, and forgot to note what settings I had, and therefore I'm back in trying all combinations of full/limited/rgb/ycbcr to get the right brightness and black levels.

Unfortunately so many forum threads here are filled with people who are convinced they have the one and only correct answer, but are often just contradicting each other.

I used the wiki (http://kodi.wiki/view/Video_levels_and_color_space) to get to a setting of:
- Kodi limited 16-235
- AMD driver full RGB 0-255
- TV limited in default setting

Unfortunately I don't know what my TV's input is (a Panasonic P42G20E plasma from 2010); on the Internet I read both that it supports full color space, and also that it only might support limited color space. Since I can't find any relevant settings in the TV menus, I'll guess it's limited only.

I find it difficult to see the best combination. In some videos I think it's too dark, but in others it seems to be better. And then there's also the desktop to think of.

Another little problem is that in both Kodi and just Windows, some of my photos (jpeg) show up with a purple 'blinking' in bright blue areas. This happens in all settings EXCEPT RGB full. So I just use RGB full. However, when I set Kodi to limited 16-235, those pictures are still purple-like where they should be blue. If I set the color in Kodi to full, I think the videos aren't right.

So, I'm full of confusion. Therefore I want to try more rational, objective measures. I know of calibrating video disks, but I saw that Kodi has its own test patterns.


But, what am I supposed to see in the test pattern?
Unfortunately there's no info in the wiki.

In particular, I guess this screen helps determining the right black and white levels:


But what should I see in the black and white squares?

In some settings, I see alternating circles in grey and darker grey.
In other settings, I see blinking circles, that disappear (i.e. take the same black/white levels as the square around it).

I _guess_ they should disappear and not get just greyer. But is this true?

Who can confirm? Thanks!

+10 karma points for whoever finally explains this...

:-)

Haha yeah. But apparently it's more difficult than I'd imagined.

Yeah. Apparently, these test patterns were handed down from the Great Old Ones or the Outer Gods, perhaps from Cthulhu himself, and their true meaning has been lost in the deeps of time and space...

Hi,

This is a variation of a pluge pattern, with both white and black. It is only accurate if you have "Use limited color range (16-235)" active.

Top left and bottom right quadrants: This is used to set the brightest part of the video. It consists of a black (0,0,0 - see note below) area with a white (235,235,235) block in the center and a blinking circle in the very center. The circle blinks alternately between 255,255,255 and 222,222,222. On a properly calibrated display you should be able to see the 222,222,222 circle as dimmer than the surrounding rectangle. But the 255,255,255 circle should look the same as the 235,235,235 surround. Some say that having a bit of headroom isn't a bad thing so seeing 255,255,255 as slightly brighter than the surrounding rectangle is okay. It's your call.

NOTE: This is incorrect! It should be (16,16,16)! No broadcast video signal should ever go below that! (0,0,0) black is illegal for broadcast video! ONLY VALUES 16-235 ARE LEGAL!!!

Top right and bottom left quadrants: This is used to set the darkest part of the video. It consists of a white (235,235,235) area with a black (16,16,16) block in the center and a blinking circle in the very center. The circle blinks alternately between 0,0,0 and 28,28,28. On a properly calibrated display you should be able to see the 28,28,28 circle as brighter than the surrounding rectangle. But the 0,0,0 circle should look the same as the 16,16,16 surround.

The thin frame line denotes a 10% overscan area.

HTH

Thank you, pixel8tor! Your explanation of the test pattern makes sense, and as it is the only explanation I've ever seen (and I've looked!), it is also the best explanation!

great, thanx!

added your info to the wiki:
http://kodi.wiki/view/Settings/System_v16#Test_patterns...

Ahh this helps! Thanks guys, especially pixel8tor!
Also a smart move to add this to the wiki!

Where can we find the test pattern in Estuary?

settings > system settings > display > test patterns...

you need to set the settingslevel to expert for the option to become available.

thanks Ronie, I didn't have the settings level set to expert when i was looking for it.

(2016-10-04, 20:50)pixel8tor Wrote: [ -> ]NOTE: This is incorrect! It should be (16,16,16)! No broadcast video signal should ever go below that! (0,0,0) black is illegal for broadcast video! ONLY VALUES 16-235 ARE LEGAL!!!

No, it's complicated and I don't pretend to know everything, but I've got BBC digital testcards which have < 16 deliberately.

I guess the "strictness" of 0 being illegal was more from analogue times. If you look at digital broadcasts there is plenty of out of range including 0 and 255.

If you compress something that is perfect 16 - 235 input the compression spreads it out, the lower the bitrate the worse it gets.