HDR Auto Mode causing HDMI Re-sync / black screen before playback

I’ve got a Z9X and a LG C1 and the HDR setting is set to Auto mode which switches to either SDR, HDR or DoVi depending on the content being played back.

Issue I’ve got is when I play HDR or DoVi BDMV content, playback begins and on the OSD I can see it’s played 4-5 seconds of the file and my C1 says no signal and displays the frame screensaver until the 5 second mark at which point the content is visible again.

If I change the HDR mode to Mapping HDR10, I don’t have this issue, if I change it to any of the VS10 modes I also don’t have issues. But I don’t want to select HDR10 all the time or DoVi all the time since I watch a fair amount of SDR content too.

I bought an Apple TV 4K to see how infuse stacks up and I honestly like it, it has a nice HDR setting that allows the UI output to be 4K DoVi and then a match format setting for dynamic range which switches between SDR, HDR and DoVi seamlessly! Doesn’t loose signal at all, buttery smooth!

Is there a setting / set of settings I need to configure to make it work seamlessly or is this just an issue that hasn’t been addressed yet?

 

HDMI will resync on a change of resolution and/or frame rate and/or HDR mode.

It depends on the display as to how this is handled - some handle it well, some not so well.

My Samsung for instance takes maybe 4-5s, my Sony a second or two, but my JVC projector can take a whole 15s!!

 

I figured it was something like this, I’ve had this for ages but what made me post it is when I got my Apple TV 4K and saw that it was so quick and snappy, and no resync, why can’t the Zidoo do that too

 

Apple TV and NVidia Shield are the only two devices I know of that that don't resync HDMI on an HDR mode change (they do on resolution and framerate) but it's not ideal because it can cause some displays to miss the change and not switch mode.

The HDMI sync is defined by the Realtek SDK which is not open source, so can't be changed.

 

I tested it quite a few times and every time it was the right colour space on my C1, maybe other displays do have that issue.

Guess if it’s baked in we can’t change it, oh well, thanks anyway