Vero4K+ Kodi 19.3 Cannot Adjust White Clipping

Whites are clipping badly on my Vero4K+ with Kodi 19.3. , but my Vero4K with Kodi 19.3 is OK. Adjusting contrast has absolutely no effect on the standard White clipping test pattern. No flashing bars will ever appear.

I am a moonlighting ISF calibrator and have been trying to solve this issue with Whites clipping on my Vero4K+ with Kodi 19.3
The issue is not present with Kodi 19.3 on a Firestick, or Windows 10, or on my Vero4K with Kodi 19.3.

I have tried 3 displays…an Epson 5050UB 4K projector, a Panasonic ZT60 Reference plasma, and a Sony X950H 4K display. I have tried every combination of Video Range settings (0-255, 16-235) on the Vero 4K+ and the displays. Whites are washed out in every case.

As I mentioned it is only the Vero4K+ with this issue.

And in the process of swapping out Vero’s to test/confirm the problem, the SPDIF port flap broke and now the SPDIF connector will not seat properly…so I have lost audio. (My AVR will not pass 4K, so direct connection to display and a TOSLINK cable was my only option) .

That’s strange. AFAIK the video and hdmi parts of Vero4k and Vero4k+ are identical. And the contrast control should do exactly what you would expect - at least for SDR (we’ve modified it for HDR so that clipping is avoided on a properly calibrated screen).

All I can suggest is to reinstall OSMC from the latest image.

If that doesn’t fix it, is your ‘standard’ White clipping test pattern in the public domain so I can check here?

Calibration test patterns are readily available on the internet
The MP4 version of the AVSHD709 is the most convenient.
…or you can grab a copy of the SDR White Clipping test pattern from here

The White clipping test pattern in the basic settings folder is the most common.
You should be able to adjust your contrast control to make the bars flash between 230-235.

Can the SPDIF port flap be repaired/reinstalled? The darn thing is so small I cannot tell if it broke or just popped out. It is used to retain the TOSLINK cable, without it the cable will not sit in the port.

I have the AVSHD709 stuff and haven’t noticed any problems with clipping once my screens are adjusted with that.

Someone reported this on this forum a couple of years ago. There’s a little spring but I think there have been different components used over time. Is this the 4k or the 4k +? I can’t recall if there was a better fix than gaffer tape.

I have just about every pattern disk available, Get Grey, Ted’s, Mascior’s Pattern Disc, Spears etc.
The Black clipping is OK, it is just the White Clipping. I can set it using an Accupel pattern generator, Calman and a spectrophotometer, but I like to fine tune using patterns sourced from the player.

The “spring” is still inside.
This is the 4K+.

I am kinda up the creek without it. Since my AVR is not, 4K the Vero is directly connected to the 4K projector, and the SPDIF feeds the AVR. I have tried a few HDMI splitters, and audio extractor devices, but so far I have not found one that will pass HDR and and low loss audio simultaneously. Many make that claim, but do not actually do it.

Eureka !! I managed to get the flap re-installed.
It took several attempts…as it is difficult to get the spring to engage the small slot on the bottom of the flap as you are twisting it in to set it…but it can be done.

Now on to the backup and re-image process.

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Did the Backup, Re-Image, Restore Backup process, but same white clipping issue.

Every White clipping test pattern I tried on the Vero4K+ had the same issue.
All my other sources were fine, including the Vero4K. But no matter how low I adjusted the contrast, no flashing bars would appear. Whites are being clipped below 230.

I can assure you my displays are extremely accurate, I have 30 years experience in the video distribution and movie theater industry. It is only my Vero4K+ source that is showing this problem.

I’m not questioning your methods, just trying to reproduce what you see here (and failing). I just ran the MP4-2c White Clipping test and I get all bars flashing at 45% contrast, no bars flashing at 55%.

Can you upload some debug logs, please? Maybe we can spot something in those.

Sure I can do that.
I’ll enable debug, and then run the video for several seconds.

Here are the logs -

Here is a video of the white clipping test pattern running as I minimize/maximize the contrast with the Vero4K+ as the source.
I can make another video using the Vero4K , if you like.

Oh, so you are adjusting contrast on your TV, not with the context menu of the video? Or is that a skin I don’t recognise?

What is the contrast setting in Kodi for that clip? A long shot since you are using a mysql library so it should be the same for all devices.

No need for a vid from Vero 4k. My Vero4k+ is doing exactly what’s expected as I reported above - using Kodi’s contrast, not that on my TV.

Is the 4k feeding through the same Denon AVR. Any chance that (AVR) is affecting the video signal?

That is the Estuary skin.

But you found the solution !!! :+1:

I never adjust the Contrast in the video context menu, as it its not persistent. Completely forgot it was even there. I would have to adjust it with every video, which is not desirable. I remember someone saying those controls were disabled for HDR videos, so it never occurred to me to adjust them.

It defaults to 57 for some reason on the Vero4K+ and 50 on the Vero4k.
That explains the difference!
It is possible I changed the default contrast setting for the previous projector a long time ago and just forgot. When I restored the backup today, it probably went back to 57.

At 50 on the Vero4K+ I am now clipping at 235 (reference white), or higher if I go lower.

I only switched to using MYSQL about a month ago. For some reason the contrast setting is not the same for each device. But you would not want it to be consistent across multiple devices, since each display’s calibration is unique.

I changed the default contrast setting in the guisettings.xml file on the Vero4K+ from 57 to 50 , and I am golden now. :smiley:

The Denon was not the issue. I only put it back in the loop because I did not want to risk that SPDIF port flap coming off again as I swap devices while troubleshooting. The Vero4K+ is now back on a direct HDMI connection to the projector and the SPDIF provides lossy audio to the AVR…it is the only way to get 4K HDR10 until I replace the AVR or find an audio extractor that works correctly. I am still amazed that my 30ft. Monoprice HDMI cables from 2008 are passing 4K HDR10.

Thanks for all your help.

Glad to hear it! TBH I didn’t know there’s an adjustable default contrast setting.