HDR Slight flickering (Workaround available)

Just tried latest nightly build of Leia for Vero 4K and, in my untrained eyes, looks like flickering and banding are a lot less noticeable.

Last one I tried was 181, I’ll try 182 tonight if I get a chance :slight_smile:

I’ve addressed your concerns on the other thread you posted. I’ll follow up there with some on-going work as well, as this is a duplicated thread.

I just started to realise that too, I just discovered the other one :slight_smile:

Before I head over there, just wanted to update on my testing last night. Thanks to @Martorias I found the Denon’s signal info page so was able to figure out a little more what was going on.

The UBD-K8500 outputs 12-bit 4:4:4 at 24hz and is my benchmark. It might not be an Oppo but it’s the best I’ve got :slight_smile:

I realise now that in the original testing I detailed yesterday I wasn’t forcing the Vero 4k to output at 10bit , so it was defaulting to 8bit. So, 8-bit, 4:4:4 at 60hz is in spec and hence worked, albeit at 60Hz.

Trying 12bit, 4:4:4 at 24hz (recreating the same signal format that the K8500 is outputting according to the Denon) gets me back to the flicking / pulsing bright areas - same for 10bit. 10/12bit 4:4:4 at 60hz gets me nothing, which makes sense as it out of spec.

So I think I’ve gone as far as I can with this and it’s over to Sam and co to work on… and judging by the other thread there is hopefully some progress on the way :slight_smile:

If you havent tried it, echo 2160p60hz420 should work fine for 10bit hdr stuff (with 444,10bit or 12bit in the attr)

Can you please point me at the Denon’s signal info page. I have an X3300W and thought I’d checked everywhere and couldn’t find it



@mlavende Setup, general information, video information, hdmi signal

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Thanks - I’ve been wondering how I know I’ve added the 444 fix properly :slight_smile:


Thanks - will try that tonight. I had previously tried it unsuccessfully (no hdmi output) but that was before realising I needed to set attr manually :slight_smile:

Just wanted to chime in here with info. There’s a test build thst seems to fix the flickering at low refresh rates but instead has some banding issues. Sam is working on it, looks really promising!

Is there any way for others to test those new test builds?

To test this update:

  1. Login via the command line
  2. Edit the file /etc/apt/sources.list
  3. Add the following line: deb http://apt.osmc.tv stretch-devel main
  4. Run the following commands to update: sudo apt-get update && sudo apt-get dist-upgrade && reboot
  5. Your system should have have received the update.

Please see if the issue is resolved.

I also recommend you edit /etc/apt/sources.list again and remove the line that you added after updating. This will return you to the normal update channel.

Just tested now with Thor: Ragnarok and its awesome, flickering has just dissapeared @ 24Hz and my untrained eyes can’t notice any kind of banding.

How did you edit the file? I get a permission denied with Putty and WinSCP.

sudo nano /etc/apt/sources.list

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Just tried the test build. Flickering is gone, but I definitely see the banding issues, got a nice blue sky in Kingsmen 2 for testing it. Receiver reports 2160p/24 with BT.2020 and 8bits.

Enable 10-bit output

Getting 10bit now with the good ol’

cat /sys/class/amhdmitx/amhdmitx0/attr

However, the banding persists. Although it’s a remux I can’t rule out it’s the video itself so I wanted to compare this to before with the workaround which switched to 2160p60. But neither the Kodi Callback solution nor syncing video to refresh rate seems to work as my AVR keeps on reporting 24 Hz while Kodi is set to 60Hz. Do I have to revert to stable branch again?

Same results as for me. If I switch mode manually to 2160p60hz420 then i get 10bit 60hz 2160p reported by my amp, but still banding.

Likewise for me, flickering gone, banding still present. I’ve just sent logs and a test clip to Sam, I’m sure he’ll be on the case.

Getting rid of the flickering is a good start, one thing at a time and all that :slight_smile: