4K TV, screen white, cannot display content 3840x2160

[frwxworx]

Overview of the Issue

4K TV (3840x2160 @ 30.00Hz, progressive) - white screen, .jpg .png content displayed for miracle of few ms and abrupted into white, blank screen.
Even default assets (Weather, Clock widget etc.) flashes quickly and goes full-white screen again.

What I tried so far without positive results, the screen still goes white:

• Added variable RESIN_HOST_CONFIG_hdmi_enable_4kp60 = 1;
• In the docker compose file docker-compose.yml added a link under the viewer service shm_size: '1gb' to enlarge "viewer" container size:
  srly-ose-viewer:
  shm_size: '1gb'

Should I mess with hdmi_group=2 (DMT) and adding custom hdmi_mode and hdmi_cvt= resolution or other?

Utterly annoying, we have 4K TVs all around the building. P.S. Legacy Screenly-OSE solution without balena-cloud dashboard support actually works with 4K TV and can display content absolutely fine.

The 4K content playback issue has been mentioned several times before:
https://forums.screenly.io/t/anthias-white-screen-on-certain-kinds-of-websites-screenly-ose-still-working/1096/11
#1498 (comment)

Reproduction Steps

Steps to reproduce this issue, eg:

• Press Add Asset
• Enter the Asset URL ...
• Press "On"
• Wait for the asset to show up on the screen

Environment

• Raspberry Pi Hardware Version: Pi 4 Model B Rev 1.2
• Raspberry Pi Network Setup: Ethernet
• Anthias Version: v0.18.6

[dr-waterstorm]

I can confirm this issue with a new Raspberry Pi 4 Rev 1.5, powered using a PoE-Hat and the latest Anthias.

[traeu]

I came acress the same problem when I tried to use 4K resolution with Raspi 3 and latest anthias version.
The page gets displayed for a fraction of a second and after that, the screen turns white.
I never managed to find a solution or workaround, so currently I am using Full-HD resolution.
I would really love to see a solution for this.

[vpetersson]

@traeu The Pi 3 doesn't properly support 4k in the first place. There are some hacks to make it work at very low frame rate, but it's not natively supported.

[traeu]

Yes, I am aware of that.
But it still works, with low framerate, even if it is not officially supported.
Because I get the same result (blank screen) as Raspi 4, which supports 4K nativly, I hope that if you fix this for Raspi 4, it will also work on older Raspis.
Right now, I don't think that the blank screen problem is a result of "hacking" Raspi 3 into displaying 4K resolution, because the same problem exists on raspi 4.

If at some point it works on raspi 4 but still does not on older raspis, I won't complain for sure!

[vpetersson]

Not suggesting the root cause is the Pi 3. Just that the Pi 3 is severely under resourced for any kind of 4ik content.

[traeu]

I guess it really depends on the content you are displaying. I use anthias to show a schedule. It's a very small web-page containing only text and some lines. No images or video content. For me, even 1 Hz framerate would be enough. But there is a visible difference between using 4K and Full HD, the TV screens are big enough that with 4K, fonts and lines look a lot sharper and reading small texts is easier.
So if I need to decide between FPS and resolution, I would choose resolution. No one would notice if that schedule gets refreshed only 1 time per second...

[nicomiguelino]

@vpetersson, could the root cause be in the Qt/C++ code?

[vpetersson]

Yes entirely possible. Would be a good test to see if this affects all asset types. If it only affects images and web pages, it's likely related to the Qt side of things.

[traeu]

@vpetersson I had some time to do this test. Its done on Raspi 3b (as you know, no official 4K support).
On Full HD: Webpages load normally, video (h264, 1080p) plays normally.
On 4K: Webpages are only shown for a fraction of a second, then only white screen. video (h264, 1080p) plays normally.

[sschroedel]

I can confirm as well.
Set resolution to FHD: Default Assets are displayed correctly
Set resolution to 4K: Picture is shown flickering some milliseconds then white only

[palmarcell]

I can sadly still confirm the issue.
I wanted to simply open up a Google Slides document with like 5 slides in it, but since the TV is 4k I can only see a blank white screen.

[ckmiecik]

I am having the same issue. I am working on a Mac building images in powerpoint and then exporting them. When I save slides from power point as images I have an option to set the resolution in pixels. I have spent hours trying out different resolutions and found that anything over 3603x2027 makes the screen go fully white. Anything I export that is 3603x2027 and lower works but does not fill my screen (since it is a 4k screen). I have also tried exporting images from Adobe indesign but I still get the same white screen. I am using a Raspberry pi4 with a 4K monitor (also same thing on a 4K Visio TV). All I need is to have images displayed and fill the whole screen (on a 4K screen). Does anybody have a fix for this?

[sschroedel]

Set the shm_size to 1gb in the docker-compose.yml this will fix it.

[ckmiecik]

When looking at my docker-compose.yml file I see no shm_size. Is this a line I need to add somewhere?

[erobinson1979]

I've added it under every container in the file, it's still not working for me.

[sschroedel]

shm_size should be present (at least it was for me). Also setting it to 1gb solved the issue. I found the reference here: #1554

[erobinson1979]

shm_size should be present (at least it was for me). Also setting it to 1gb solved the issue. I found the reference here: #1554

Thanks for the reply and the source info. I was able to edit my file to match that post and remove the extra shm_size entries, but I'm still experiencing the same symptoms as #1554

My next step is probably going to be finding a Pi 3b and using the older version that works.

[ckmiecik]

Thanks for the update. I also tried editing the file but still the same result. If I am understanding this correctly it seems like this should be fixed when #1887 is resolved. The only thing I am worried about, is that it sounds like this is going to fix web pages but I'm hoping it also fixes my issue where I'm trying to just display .jpgs

[nicomiguelino]

It might take a while for the Docker images to be built. You can update your Anthias instances once the following CI run is finished: https://github.com/Screenly/Anthias/actions/runs/9101858709.

However, do take note that it still takes a while for assets to be fully rendered, like web assets and images with at least 3840x2160 of resolution. (That's for another issue.)

[traeu]

I can confirm that this fix also works for Raspberry Pi 3B that has no official 4K support.
After updating anthias, I was able to get working 4K output!
Thanks for fixing this.