HDR Colors

Single Board Computers KVIM3/3L
1

Hello,

I got a VIM3L HTPC kit, now on 9.2.4.2 after initial update. I have it hooked up to a Samsung UN55NU8000 TV. When I play 4K HDR movies, the colors are somewhat washed out. It looks like the colors of the video player OSD are similarly washed out. I’ve been trying various combinations of settings on the TV (HDMI UHD Color is on) and the box, but can’t seem to find the combination.

I made this log file from a couple movies in hopes someone who can read it better than I can might see what I’m missing.
http://paste.kodi.tv/gikosuviha

Thank you

2

Have you changed any Kodi settings from the default? If you have changed anything, start with basic default settings and see if the picture quality increases. Everything should work out of the box without changing anything. Can you confirm that your TV trigger HDR? Furthermore, take a look at the settings experts recommend as a baseline for your TV and change the values to what you find to be best: https://www.rtings.com/tv/reviews/samsung/nu8000/settings

3

I started from default, and have tried so many combinations of settings on the box and TV, I was hoping maybe something would be shown in the log that would show “X” is supposed to happen at some point when the movie starts playing but doesn’t. I see “HDR” come up on the TV info but the colors don’t seem to reflect that.

4

Well, there are some errors in your log such as:

2020-10-05 13:02:49.131 T:4066140176   ERROR: GetString: error reading /storage/.kodi/userdata/disp_cap
2020-10-05 13:02:49.132 T:4066140176   ERROR: GetString: error reading /sys/class/amhdmitx/amhdmitx0/custom_mode
2020-10-05 13:02:49.132 T:4066140176   ERROR: GetString: error reading /storage/.kodi/userdata/disp_add
2020-10-05 13:02:49.132 T:4066140176   ERROR: GetString: error reading /run/disp_add

Could you please completely re-install CoreELEC? Then before changing any settings, try some HDR samples. Including .mkv/.mp4 samples. There are multiple demo samples over at https://4kmedia.org/.

5

These errors are not significant in any way. They are mostly just showing that the various options for overriding the detected display settings are not being used.

6

Check player info during playback and make sure it is outputting BT2020. If instead it is in Rec 709 then you have to emable HDR in your TV HDMI. On Samsung I thing it is called “enanched input”

7

HDMI UHD Color is on and the TV shows “HDR” while playing.

On the 4K, it shows:
Display mode: 3840x2160p24Hz
Pixel format: 10-bit, YUV444
EOTF & Gamut: HDR10 BT.2020nc

and for 1080p blu-rays:
Display mode: 3840x2160p24Hz
Pixel format: 10-bit, YUV444
EOTF & Gamut: SDR BT.709

When I bring up Player process info to see this, the red box and red text seem full brightness on the regular blu-ray and a bit paler on the 4K. The interface while I’m browsing for a movie seems to be the full brightness as well.

8

CoreELEC is ok. I would check the picture setting in the TV (saturation, etc…)

9

If you leave the GUI at 1080p, do you see any differences in quality? It seems that the issue is the picture quality of your TV, so you have to change the settings to increase the quality. Remember that the picture settings are different for SDR and HDR, so you might have to change the picture settings while your TV is in HDR mode. Simply play the first 4K HDR file, pause the video and start changing the settings using the experts recommended settings as a baseline: https://www.rtings.com/tv/reviews/samsung/nu8000/settings

10

The Rtings settings went way dark for me. At this point, I think I’ll have to wait til I get another HDR TV to see if this one is good or not.

11

Perhaps I should have pointed it out better, but you should not use the same settings as they don’t necessarily apply to your specific TV. Start with the same settings as a baseline and then adjust settings which you find to increase the picture quality :+1: Hopefully that will be enough, and if not, I guess your best bet is to swap to a new TV.

12

Yeah, I’d already been through every menu on the TV and Coreelec ten times which is why I was hoping for something in the log that would point to something.

13

I had a Samsung NU7100 TV. It was a pain to calibrate it for HDR input signal.
The colors did indeed look dull and washed out. The settings that helped to fix this are Contrast Enhancer - it should be enabled (try Low or High) and Gamma ST.2084 (try 1,2 or 3).
My other settings as far as I remember were:
Picture Mode: Movie
Brightness: 5 (at max)
Contrast: 45
Colour: 25

14

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