No 4K resolution on RPI4

erik070 · December 3, 2020 at 8:35 PM

I seen several posts on how to enable 4K on RPI4 with Libreelec but I can't get it to work.

On the RPI4 with Libreelec in a Argon One case i have the High Speed HDMI cable connected to HDMI port 0. It's connected to my TV's HDMI port 1. TV is a Philips 50PUS8804.

The problem: in LIbreelec/Kodi I can only choose 1920x1080 @ 60hz and lower resolutions. Whitelist shows the same, only lower than 1920x1080.

My TV should be perfectly capable of showing a 4K image.

Could my case be a problem? I use a Argon One case which has a HDMI extension, maybe this is causing problems? (will try without case later, wife watching the TV now)

So I'm left with a lot of options, but cant figure out any working solution(except case maybe). Anyone have experience with 4K on Libreelec RPI4 and care to share their config.txt?

Anyone have experience with the Argon One case with 4K output?

Here my config.txt , maybe I've done it wrong?

gpu_mem=320

force_turbo=0
# hdmi_force_hotplug=1

hdmi_ignore_cec_init=1

hdmi_drive=0

hdmi_ignore_edid=0xa5000080

#hdmi_mode=102

hdmi_group=1

#hdmi_enable_4k=1

hdmi_enable_4kp60=1

[all]

include distroconfig.txt

dtparam=i2c=on

enable_uart=1

I commented out hdmi_mode as forcing 4K seems to result in a blank screen.

Do I need to enable both "hdmi_enable_4k=1" and "hdmi_enable_4kp60=1"?

**HiassofT** · December 3, 2020 at 11:22 PM

hdmi_enable_4kp60=1 is the correct setting. Also remove all other hdmi options you added and make sure you've enabled "Ultra HD deep colour" in your TV's settings (usually that setting is separate for each HDMI port, and it might be called slightly differently on your TV).

so long,

Hias

erik070 · December 4, 2020 at 10:14 PM

Removing those other HDMI settings form the config.txt did the trick. Awesome and thanks!

And you are also correct on the HDMI setting on the tv. But that was already set correct in my case. For anyone searching for setting on a Philips Android tv:

All settings > general > HDMI ultra HD

Set this to Optimal

atarixle · May 7, 2021 at 7:30 PM

Sorry to dig out this slightly older thread, but:

on my Samsung TV, neither the trick in the config.txt works, nor 4K at all.

When my RPi boots up, the bootscreen is shown in 4K - including the LibreELEC logo.

But the whole kodi GUI is 1080 only. In the kodi-settings, 3840x2160 is set up, but the whole GUI is in HD only.

Photos, Menus, ... is HD only, even 4K is correctly set.

And, while I setup everything for 4k 60fps, it offers me only 30fps (beside the fact that is HD only).

Any suggestions?

**HiassofT** · May 7, 2021 at 8:05 PM

Which LibreELEC version are you using?

On LE10beta 4kp60 output isn't implemented yet (it's currently being worked on).

LE 9.2.6 supports 4kp60 if you add hdmi_enable_4kp60=1 to config.txt and enable "ultra hdmi deep colour" (or some similarly named option) for the HDMI port in you TV's settings.

The GPU in RPi4 is a bit underpowered for 4k rendering therefore GUI resolution is limited to HD. You can disable the limit in settings->system->display (you need to switch level to expert to see it) but then GUI navigation will be quite slow - I wouldn't recommend doing that.

Actually it's best to change the display resolution to HD (in general your TV will do better HD->4k upscaling than kodi/rpi) and enable 4k modes for video playback in the whitelist.

so long,

Hias

noggin · May 7, 2021 at 11:37 PM

Quote from HiassofT

Which LibreELEC version are you using?
On LE10beta 4kp60 output isn't implemented yet (it's currently being worked on).
LE 9.2.6 supports 4kp60 if you add hdmi_enable_4kp60=1 to config.txt and enable "ultra hdmi deep colour" (or some similarly named option) for the HDMI port in you TV's settings.
The GPU in RPi4 is a bit underpowered for 4k rendering therefore GUI resolution is limited to HD. You can disable the limit in settings->system->display (you need to switch level to expert to see it) but then GUI navigation will be quite slow - I wouldn't recommend doing that.
Actually it's best to change the display resolution to HD (in general your TV will do better HD->4k upscaling than kodi/rpi) and enable 4k modes for video playback in the whitelist.
so long,
Hias

Display More

The Pi 4B doesn't support 4K60 HDMI output with 4:2:0 subsampling - which is the only format some UHD TVs support at 4K60. If your TV is one of them - you're unfortunately out of luck.

If your TV supports RGB (and I think YCbCr 4:4:4:) 8-bit at 4K60 then it should work OK. Similarly 4K30 and below at RGB 8-bit.

Also - some TVs support different levels of 4K on different HDMI ports. My Sony supports more on HDMI 2 and 3 than it does on HDMI 1 and 4. (Though this is usually related to 4K60 4:2:2 12-bit support - which is higher bandwidth. The Pi 4B doesn't currently support 4K60 4:2:2 output - but there is hope it will.)

atarixle · May 9, 2021 at 11:37 AM

I didn't realize that this all will be a bit of a hazzle. Since the whole Samsung / Tyzon rendering is in HD only (including Samsung Internet and Photos, all apps, ...), I was hoping to be able to watch Photos on the Pi at least at 4k.

Thank you for your hints. I'll give them all a try and reply once more if I succeed.

Btw. it's 9.2.6 ... the current stable one.

Btw(2):

ok, I guess I'll stick with 1080p60.

I kinda succeeded having a 4K output. But the still 1080p UI was stuffed into the upper left quarter of the screen.

**HiassofT** · May 9, 2021 at 2:43 PM

Quote from atarixle

I kinda succeeded having a 4K output. But the still 1080p UI was stuffed into the upper left quarter of the screen.

You need to restart kodi / reboot LibreELEC then it should work (it's also mentioned in the info line of the GUI size limit option).

so long,

Hias

atarixle · May 9, 2021 at 5:52 PM

I did. The squeezed UI came after the reboot.

No 4K resolution on RPI4

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