[TESTING] 4K HDR playback with banding & flickering fixes


Uhm for amp settings nothing really, using the media player hdmi port. All hdmi setup stuff is off. Tv is just ultra deep color thing on, using hdmi3

Edit: checking the hdmi signal thing on amp shows 4k:24hz bt2020 10bit, so all seems well.


With the April update, banding is still present. I have a LG B6 OLED. Enabled autoswitch HDR option.
Testing with Dunkirk.

When he gets to the beach at around 3m30sec. the sky clearly still has banding, though the photo doesn’t show it very well.


Do you have 10-bit output enabled via CLI?
You’ll need that to avoid banding



Did not. Thought that was fixed by using the new HDR autoswitch option?


As per the release notes this is still experimental for now. It will replace the need to set anything via the command line in the near future


I have a LG OLED65C7V with banding issues with the vero 4k osmc, including the April release. I’m using blade runner 4k movie and watching the gray clouds in the first few minutes. I have tried the previous “444,10bit”, “round0”, “round1”, “dither1” workarounds to no effect. In the March release the “dither1” workaround was the only thing that removed my banding. Probably going to downgrade from April to March release.

BR anden4711


Hi @sam_nazarko,

Another Denon user here (X2300W) experiencing dots/sparkles.

I’m using High Speed AmazonBasics HDMI cables - a 3ft one from the Vero 4K to the AVR (into the Media Player HDMI port), then a 10ft one which is buried in the wall from the AVR to the wall-mounted TV (65" Sony XD9305).

I have had echo "444,10bit" > /sys/class/amhdmitx/amhdmitx0/attr in my /etc/rc.local for a while now to ensure 10bit content is displayed as such.

I also see these white sparkles occasionally with 4K/HDR content - it only occurs on some content some of the time in dark areas of the picture - but for me never all over like in the image above. If I pause the content, the sparkles remain and even show up in the Kodi UI overlay elements if they are also of a dark colour.

I’ve replaced the 3ft cable with a brand new one and the issue remains.

My Samsung K8500 UHD player is connected via the AVR with the exact same brand of cable (connected to the BluRay HDMI socket, so even further away) and has zero problems with sparkles with 4K/HDR discs so I don’t think the cables are the issue…

I can try to get some clips of the affected content it it will help or please let me know if there’s anything else you need to know or would like me to try…


You don’t need to set any of these values anymore.

Just enable the 10-bit video output



I noticed this behaviour with a cable recently but not with another device. The other device wasn’t outputting 444,10 which will expose the problem more clearly.

If you are confident it’s not a cable issue then some logs may help.


If I can reproduce it again I’ll certainly try to get some logs at the time. It doesn’t always happen unfortunately.

I did just check and when playing a 4K UHD/HDR disc on the Samsung UHD player, my AVR shows the exact same HDMI signal (4K/24Hz, BT.2020 YCbCr, 10bits) as when playing 4K/HDR remuxes on the Vero 4K with the 444,10bit attribute setting so that pretty much rules out the cables.

Additionally, the new HDR autoswitching feature in the System, Display menu causes issues for me. If I enable it, when playing suitable content it certainly seems to toggle the 444,10bit attribute (whilst checking on an SSH console) but I only get a few seconds of playback before all picture and sound disappears and my TV switches to a “no signal” screen. The content is clearly playing still though, since pressing Stop returns me to the Kodi menu where the picture then returns (and the attribute appears to have changed to “reset”).

I’ll be retaining the rc.local setting for now and disabling the HDR autoswitching.


Hi I have a b7 lg oled, just applied the April update and had a look at first few mins on blade runner 2049 and didn’t notice any banding. Not using any of the ssh stuff we did before just enabling hdr autoswitching in settings.


Same hdmi problem on my side too. Just tried the hdr autoswitch (BUT without enabling the 10-bit video output ! ) and after 1 hour, I’ve lost the display signal on my projector for few seconds 2 times during next 10 minutes. Sound was still playing on my NAD amp… As it is experimental, I’ve disabled it.


Onkyo TX-RZ810 and Samsung JS9000 TV. With the HDR Autoswitch enabled, my screen never shows any of the movie. It goes black for about one minute, than blue for the same time period, then black again. I hear no audio. The Amp shows it is not receiving anything it can recognize. When I press ‘Stop’, it reverts back to showing the list of movies. Have disabled it. I have just discovered that all my 10 bit 4K movies are playing back as 8 bit.


I wish to log in to the Vero 4K, to change the 8 bit to the 10 bit. There has been a few posts mentioning this but I can’t remember where I saw them. I have never ‘logged’ into the Vero, (or anything Kodi) and know very little about Kodi.

Can someone tell me the best way to ‘log in’ (do I need to download something?) and how to edit what ever is needed so as to get the Vero to display 10 bit?. I remember reading something about the folder(s) I need to edit are hidden? If so, how do I change that?

I use a Windows 10 laptop and also have a Bluetooth keyboard with a Bluetooth USB dongle.


Details regarding how to access the command line interface can be found here on our Wiki: https://osmc.tv/wiki/general/accessing-the-command-line/

For the 10 bit command search for “10 bit attr” should find something


Thanks for the information. If I am successful in changing the 8 bit to 10 bit, will I have to do it every time there is a Vero 4K update?


No it seems to stay unless you do a full re-install.


@rakesh84 ,
I downgraded to osmc March release, extreme horizontal color banding in the gray clouds like in the latest April release, it’s like there is serious issues with the color bits in the content sent to my LG C7 for that HDR bladerunner 4k movie. The only thing that makes the color banding go away is the manual “dither1” setting in the driver debug. The 10 bit setting doesn’t do anything. Maybe the dither1 setting only hides the underlying problem, and doesn’t solve it, not sure. I tried to take some Kodi screenshots, but only got black screens. Would be nice to show how bad it looks.


I log in locally and enter user and password.
Am left with osmc@osmc:~$

I read this:

which says this:
“To enable viewing of these files from within Kodi, you need to enable:
System->Settings->Appearance->File Lists->Show hidden files and directories”

Do I enter the above after the $

As you can see, this is my first time trying this.
It has been said on this OSMC forum, that a Newbie Guide would be most welcome. I second that as I do not want to waste your time answering such basic questions, I would rather read a Step by Step guide.


@sam_nazarko… does we need this entry in the rc.local also after the April update or is this a part of the new build?