When you're at the forums main page, use the search function (magnifier icon), and you'll find:
The download is a bit hidden under the dirt, because it's chewitt 's unofficial work.
RC sends IR codes when you press a button - that's it. Same thing like on any other OS. 
What's the format of ps3remote.evmap? <key_LIRC> = <key_Kodi>?
I am using a generic breakout board for the PCM5122
If you use a HiFiBerry clone, then it doesn't work for obvious reasons.
Thanks. Do you use HiFiBerry DAC+ in standard edition (RCA version), or something else?
PS: Try dtoverlay=hifiberry-dac (without the "plus", reboot necessary).
Please check the available audio output devices. Maybe you just have to select the device again.
Could be a USB controller issue, where LE probably uses other drivers than Ubuntu.
There is no motivation among LE dev's to fix this, because your motherboard is outdated.
Olivastro Translate please, and you'll help others.
You can do that without a keymap editor by creating keyboard.xml at /storage/.kodi/userdata/keymaps.
Then you can re-map action ID's to other functions, like red remote button to mute audio volume:
<keymap>
<global>
<keyboard>
<red>mute</red>
</keyboard>
</global>
</keymap>I connect directly to the TV and create an edid file via "getedid create"
Do you get two identical HDMI modes with or without a custom EDID? That's one approach of the above thread.
This thread has some ideas how to change brightness on RPi 4: Click!
Does overclocking Pi4 affect the smoothness , responsiveness and overall performance of LibreELEC?
Yes.
I've never seen a DSI driver developer on this forum. So I think you're searching at the wrong place.
Usually it goes like this: Find an open source driver, and adapt it for your needs.
I found this thread on the RPi forums, which is a good starting point: Click!
I downloaded the file but could not find the .upgrade folder, or figure out how to create one.
It's a hidden folder, use cd /storage/.update.
You can also use wget https://test.libreelec.tv/LibreELEC-Generic.x86_64-11.0-nightly-20220123-baa84f0.img.gz to download the file when you're in that folder.
Yes, switching among LE 9 and 10+ will break things, but any switch among LE 10+ versions should work fine.
Niceguy We want happy users, so I've set you to un-moderated. 
Also, try disabling HW decoding of video codec (don't know which it is, for me it was VAAPI), I had simmilar issues in the past, but I have old Celeron class CPU with bugged GPU. Couldn't even watch SD resolution x264 without desync. x265 worked, but only because it has no HW acceleration and it decodes by software.
You've been posted a tweak for another Intel user with nearly the same issue:
RE: Librelec Matrix 10.0.1 freezes randomly when playing video
So maybe this is also helpful for grandnagas . Try it!
Then I also suggest the latest nightly LE. Copy the .img.gz file into the .update folder, and reboot. You can downgrade back to LE 10.0.1 the same way.
The out-of-sync issue is visible at the log:
2022-01-14 21:47:58.606 T:1011 DEBUG <general>: CVideoPlayerVideo - CDVDMsg::GENERAL_SYNCHRONIZE
2022-01-14 21:47:58.607 T:1008 DEBUG <general>: CheckPlayerInit - dropping packet type:2 dts:2034824000.000000 to get to start point at 2035783000.000000
2022-01-14 21:47:58.607 T:1008 DEBUG <general>: CheckPlayerInit - dropping packet type:1 dts:2034827000.000000 to get to start point at 2035783000.000000
2022-01-14 21:47:58.607 T:1011 DEBUG <general>: CVideoPlayerVideo - Stillframe left, switching to normal playback