No HDR10 playback on UHD Projector if AVR and Projector are turned on in wrong order. LE11 nightly Rpi4

lobbie1978 · January 19, 2023 at 5:35 PM

Hi guys,

An issue popped up yesterday and I wonder if it can be solved.

I'm running the latest Nightly build of LE11 on my Rpi4.

My Rpi4 with LE11 nightly is connected to my Sony AVR which has two HDMI outputs; one is connected to my Sony (non-HDR) UHD TV, the other is connected to my Optoma UHD HDR10 projector.

When I turn on my Projector AFTER turning on my AVR, sometimes the projector is not receiving HDR for some reason played by LE. HDR is greyed-out. If I turn the devices on the other way around, it works normally.

I wonder if this has something to do with EDID?

Any idea's?

Cheers!

Rob

**Da Flex** · January 19, 2023 at 9:06 PM

I would guess your AVR is the culprit here. It probably doesn't update the projectors HDMI capabilities correctly.

If you want to be sure, create a log when HDR10 is missing. If HDR10 isn't in the log, my theory is verified.

Please provide a full debug log.

How to post a log (wiki)

1. Enable debugging in Settings>System Settings>Logging
2. Restart Kodi
3. Replicate the problem
4. Generate a log URL (do not post/upload logs to the forum)

use "Settings > LibreELEC > System > Paste system logs" or run "pastekodi" over SSH, then post the URL link

**chewitt** · January 20, 2023 at 8:12 AM

The behaviour is all about EDID data and the properties exposed to Kodi. Kodi only reads this data once at startup, so if the projector is not on when Kodi starts, the AVR does not show this to Kodi and thus HDR10 is not availble. The normal way of dealing with that is to hardcode the EDID data with "getedid create" so the Pi board always believes the AVR/TV to be connected. The spanner in that plan is you have two HDMI outputs and they aren't equal. Perhaps hardcode the Projector EDID and avoid playing HDR media on the TV (which you probably don't do).

lobbie1978 · January 25, 2023 at 6:08 PM

Quote from chewitt

The behaviour is all about EDID data and the properties exposed to Kodi. Kodi only reads this data once at startup, so if the projector is not on when Kodi starts, the AVR does not show this to Kodi and thus HDR10 is not availble. The normal way of dealing with that is to hardcode the EDID data with "getedid create" so the Pi board always believes the AVR/TV to be connected. The spanner in that plan is you have two HDMI outputs and they aren't equal. Perhaps hardcode the Projector EDID and avoid playing HDR media on the TV (which you probably don't do).

Thanks chewitt! What would happen if I play HDR media on the TV? Wouldn't the TV just ignore the HDR signal and just play the content in UHD without HDR?

**Da Flex** · January 26, 2023 at 6:04 AM

Quote from lobbie1978

Thanks chewitt! What would happen if I play HDR media on the TV? Wouldn't the TV just ignore the HDR signal and just play the content in UHD without HDR?

If you don't hardcode anything, HDMI will do the usual negotiation, which means SDR delivery to your TV.

lobbie1978 · January 26, 2023 at 10:40 AM

So yesterday I hardcoded EDID by SSH'ing into the Pi while a HDR movie was playing on my projector (TV was off) and programming EDID with getedid create

It did not work

When I restarted the projector, the AVR and LE, the HDR availability was gone again. I am so confused now.

Interestingly enough, this issue never came up with LE10. I had to update to LE11 nightly, because KODI on my PC automatically updated to the latest version, which altered my database which is running on my NAS.

Any ideas?

**Da Flex** · January 27, 2023 at 6:01 AM

Use the kernel parameter method: Click!

lobbie1978 · January 27, 2023 at 7:54 PM

Oof, that looks like some advanced stuff. Don't know if I can manage that. I do read all about resolutions, but the issue is not resolution, that's all fine. It's HDR that doesn't work.

**Da Flex** · January 27, 2023 at 9:15 PM

HDMI video mode is more than just resolution, it also includes color space.

**chewitt** · January 28, 2023 at 5:17 AM

Quote from lobbie1978

What would happen if I play HDR media on the TV? Wouldn't the TV just ignore the HDR signal and play content in UHD without HDR?

The RPi4 thinks an HDR compatible panel is connected so will output with HDR. If the TV has HDR > SDR auto-conversion then it would be able to handle the HDR signal and display in SDR, but generally the only TVs that have conversion capabilities are the ones that support HDR. So I think it is rather unlikely that it will be handled and I would expect green/purple tinged and washed colours due to the wrong colourspace.

**chewitt** · January 28, 2023 at 5:23 AM

Quote from lobbie1978

So yesterday I hardcoded EDID by SSH'ing into the Pi while a HDR movie was playing on my projector (TV was off) and programming EDID with getedid create. When I restarted the projector, the AVR and LE, the HDR availability was gone again.

I would keep things simple and capture the EDID direct from the projector without the AVR inline. Check it works over reboots before you add the AVR back into the mix.

lobbie1978 · March 6, 2023 at 7:07 PM

So you are suggesting to connect the Pi directly to the Projector, then play HDR content and capture the EDID?

I did a clean install of LE11 this afternoon hoping that it would solve things, but it didn't. I did find that pulling the powercord from the AVR when the projector and LE were running and then reconnecting the AVR again made HDR playback work again.

So somehow it seems to me that the AVR is the culprit here. Very strange, because it fully supports HDR 10 passthrough and it has worked flawlessly in the past... It even supports 4k/60p which I'm not using.

**chewitt** · March 7, 2023 at 9:24 AM

No need to play HDR content as the EDID data is static (doesn't change during playback), but connect direct to the TV/Projector to capture the correct EDID data with "getedid create" and then reconnect with the AVR in the chain.

lobbie1978 · March 20, 2023 at 3:01 PM

Little update on this issue:"

Next to the HDR playback issue, I also experienced dropping signal to the projector. I didn't linked those two together, but I managed to identify the cause of the dropping signal (something to do with the HDMI A/B output) and when that was fixed, I have no issues anymore with HDR. It works now.

In detail:

During playback on my projector, the signal dropped many times. Sometimes >10 times during a movie.

I found out that when I set my receiver to output to the projector only (HDMI Out B instead of both A/B) that issue is solved (don't know why, I never had any issues with this, but whatever).

Since I started to set the HDMI output to the projector only, the HDR playback works as expected. No more issues there. Weird.

Now I need to find out why the HDMI Out A/B causes this. I never had this issue before, but I think it has something to do with the Sony TV that is connected to HDMI A. Maybe a setting is causing this, not sure. Any suggestions are very much appreciated.

So anyway, the HDR issue seemed to be caused by the receiver/tv and not by the Rpi/LE.