Help with 4K 60Hz on RPi4B 8GB, LibreElec 10.0.1, also have issue with washed out colors on startup sometimes

  • I'm having 2 issues with my Pi and hoping someone can help.

    RPi4B 8GB

    LibreElec 10.0.1

    8K hdmi cable plugged into HDMI 1 the furthest from the power connector (not HDMI 0, I can't get any output from that port)

    1st issue:

    I can't get it to output 4K 60Hz. I can only get 4K 30Hz. (AVR and TV are both minimum 4K/60hz).


    2nd issue:

    Sometimes when I boot the Pi the colors are all washed out and I need to either turn the Pi on and off or power cycle my AVR and then the rich dark colors come back.


    I'm guessing it's probably how I have my Config file setup.

    I don't SSH into it, I use NotePad ++ to edit it.


    Here's everything I have set in it:

    hdmi_force_hotplug=1

    sdtv_mode=0

    sdtv_aspect=3

    hdmi_force_edid_audio=1

    hdmi_ignore_cec=1

    hdmi_drive=2

    hdmi_group=1

    hdmi_mode=97

    hdmi_pixel_encoding=2

    hdmi_ignore_edid=0xa5000080

    hdmi_enable_4kp60=1

    hdmi_ignore_cec_init=1

    I read something about having to do "Video=" in LibreElec 10 but I couldn't figure out what to do it on and where to put it.

    Hopefully someone can see where I've gone wrong with my config file.


    Thanks

  • Most hdmi_ settings in config.txt will be ignored after LE9.2 as we use the kernel DRM framework, e.g. "video=HDMI-A-1:1920x1080M@60" can be added to boot params in cmdline.txt (not config.txt) to force 1080p output for GUI. You should also be using the HDMI-0 port (nearest the power connector) not the HDMI-1 port. I'll also comment there is very little real-world need for 4K60 since practically all 4K content is 4K24 or 4K23.976 format, and you do not want to run the GUI at 4K unless you want a slow GUI - use 1080p and whitelist/adjust-refresh to switch to 4K modes when needed.

    I'd suggest starting over with a clean SD card with no extra config applied and the latest LE11 nightly.

  • Thanks so much for the reply!

    Okay, I won't bother with 4K60 then.

    My 4K GUI isn't really slow, not lighting fast but definitely not slow, I don't have a ton of stuff on Kodi though.

    It's on an 83" TV so 1080p looks terrible at that size. I don't mind sacrificing a bit of speed and snappyness for sharp menus.

    3 questions is you don't mind.

    1. I couldn't get a video output on HDMI-0, is there a setting I'm missing for that or could I just have a bad HDMI port?


    2. Is there somewhere I can go online to figure out what exactly I can add to the cmdline.txt file (probably using NotePad++ since I don't SSH into my Pi or have a command line)?

    I was able to find lists of what can be added to the config file, is there a similar list for the cmdline file for video stuff?

    I'd like to be able to force hdmi outputs if no display is detected (TV isn't turned on first) and stuff like I could with the config file.


    3.Any idea how to fix washed out colors when booting the Pi sometimes and then I need to reboot the Pi and it fixes it?

    Maybe forcing things like limited or full RGB in the cmdline can fix that?


    Thanks again for your reply. Really appreciate it!

  • 1. No idea, it should just work. Latest LE11 nightlies have fixes for some situations where blank screens might be seen. Again, I suggest you try the latest nightly on a clean SD card with no attempts to pre-fix problems.

    2. RPi websites should have authoritative documentation. The main point of the switch to the Linux kernel DRM framework is that most of the old config.txt hacks available in the older downstream vendor kernel should not be needed now. Users assume reduced documentation on config.txt means something is missing, but that's not correct. You can capture the EDID data from HDMI and force detection of the TV; run 'getedid create' with a working HDMI connection.

    3. Nope. Never seen it reported (never seen it myself). You can force output modes (as previously hinted) but you cannot force colourspace.

    Current Kodi skins are 1080p resolution so either Kodi or the TV has to do upscaling to 4K and generally keeping Kodi on 1080p and allowing the TV to do the upscale results in lower load on the RPi (so faster RPi) and equivalent or better results on-screen as the TV has dedicating scaling hardware. So far that that guidance seem to be true for the majority but I guess the results are ultimately subjective.

  • 1. No idea, it should just work. Latest LE11 nightlies have fixes for some situations where blank screens might be seen. Again, I suggest you try the latest nightly on a clean SD card with no attempts to pre-fix problems.

    2. RPi websites should have authoritative documentation. The main point of the switch to the Linux kernel DRM framework is that most of the old config.txt hacks available in the older downstream vendor kernel should not be needed now. Users assume reduced documentation on config.txt means something is missing, but that's not correct. You can capture the EDID data from HDMI and force detection of the TV; run 'getedid create' with a working HDMI connection.

    3. Nope. Never seen it reported (never seen it myself). You can force output modes (as previously hinted) but you cannot force colourspace.

    Current Kodi skins are 1080p resolution so either Kodi or the TV has to do upscaling to 4K and generally keeping Kodi on 1080p and allowing the TV to do the upscale results in lower load on the RPi (so faster RPi) and equivalent or better results on-screen as the TV has dedicating scaling hardware. So far that that guidance seem to be true for the majority but I guess the results are ultimately subjective.

    Thanks again for the reply! I just ordered a new SD card to do a fresh install (keeping the original as a working backup).

    I just did a bit of quick google searching and looks like to do 'getedid create' I have to ssh into my pi which I've never done. Sorry not an advanced Pi user :) So I'll have to figure that out.

    I previously tried the 1080p just from the Kodi Menu and it looks terrible on the TV. The TV wasn't upscaling to 4K. I'll maybe play around with it a bit more in the cmdline but for now 4K30Hz is working good for me. Not AS snappy as 1080p but pretty good.

    Just until I figure out the 'getedid create' would I just add 'video=HDMI-A-1:3840x2160M@30' to the cmdline file?

    From the looks of it that will set HDMI 0 to 4K30hz.

    Does it also do similar to what the old "hdmi_force_hotplug=1" used to do (force output when no display or TV not on) or is there another line I can put in the cmdline file for that?

    This is just a temporary fix until I have time to figure out 'getedid create' and ssh into my Pi.

    Thanks again!


    The cmdline.txt settings for video are just standard linux, not pi specific. See here:

    https://www.kernel.org/doc/html/v5.10/fb/modedb.html

    or

    https://wiki.archlinux.org/title/Kernel_mode_setting

    Thanks!

    Unfortunately I'm not well versed in Linux, looks like I have some reading and learning to do :)

    Edited once, last by Lain: Merged a post created by Lain into this post. (January 19, 2023 at 2:45 PM).