OK, so after some testing I have found an incompatibility with Kodi / LE 9.80 nightly and ESP32CAM. On LE 9.2.6 it partially worked but unreliably.
I have tested the same with another camera based on mjpg_streamer and it works fine.
Also I have discovered that UVC drivers are working fine so it's possible to stream or make a pictures from an UVC compatible USB webcam connected locally.
I am sorry but it's another story - maybe we should not mix more different questions to the same thread.
I don't know (yet) the kodi2mqtt add-on (and it looks it's not an official add-on in LE?) but make sure you have installed / configured all (possible) necessary prerequisites, maybe you should look into kodi2mqtt documentation or visit some related forum thread.
In this case you don't have (at least) the path to the paho.mqtt.client (which is IMHO the important prerequisite) module specified so that's why you can't run the test script.
Yes I have also reported that issue ( RPi 4B - rpi-eeprom-update does not work on latest LibreELEC 9.80 nightly ) but it was on Nightly 9.80 builds, I think that official LE builds are OK.
USB booting on the RPi4 may require a firmware update first...
Yes you are right but the firmware is a part of OS (lies on partition on SD card / USB flash), bootloader is inside of RPI's eeprom. If you replace the SD card, you also replace the firmware. That's why I mentioned the bootloader needs to be upgraded to latest version first (and perhaps configured properly but a default should be OK), this is an essential task (ther're also some updates related to SD cards compatibility so it's good to upgrade anyway). As soon as this is done, he can boot directly from USB mass storage device with LE 9.2.6 image which already contains the proper firmware.
The 'simplest' option for me was to install Raspberry Pi OS (formerly Raspbian) onto an SDcard, and update both kernel & USB firmware to enable USB booting.
Yes that's true, the Bootloader EEPROM and VIA USB3 Firmware (which by the way shoud be also at latest version 00138a1) can be updated from running LE but in this specific case when LE can't boot I would also go through Raspberry Pi OS placed on the same SD card using the official Raspberry Pi Imager to check if the SD card is working ever with his RPi 4B.
I would also try to use some USB mass storage instead of SD card - I have experienced some SD cards (despite NOT cheap) were not fully compatible with RPi 4B.
When booting from USB, it's just necessary to put dtparam=sd_poll_once=on to /flash/config.txt (otherwise there're SD card related errors filling log).
Also make sure you have the latest (at least stable) bootloader version installed ( rpi-eeprom/release-notes.md at master · raspberrypi/rpi-eeprom · GitHub ).
For that purpose (to run a script by IR remote control button) I am using irexec as described here:
RE: execute shell scripts with LIRC using custom key names
It works great and it's easy to configure.
Use irw command (and press IR remote control buttons) to see the key names currently mapped.
No problem. I'm glad I could help.
Please click EDIT THREAD button and select option Mark as Resolved.
Well, forget the libraries and double check your configuration again instead.
Why don't you try the same (earlier working on RPi OS) display settings in LCDd.conf?
I see you changed the Speed parameter from 19200 Bd to 115200. Some displays have the DIP switch to select the preferred speed so if you did not set that properly, the garbage on your display is the logical result.
OK, I understand. So please don't mix too many things together and focus on LE.
I think LCDproc works on LE as same as on Rpi OS if properly configured, just the config file location / driver folder location is different. I can recommend to do / check these steps in LE:
1) Put the appropriate necessary options to /flash/config.txt and check if the display is properly attached, check if there's no HW / SW conflict on UART
2) Install the LCDproc add-on and configure it in GUI to select the correct driver. Then reboot LE and check if the LCDd is running with proper parameters using ps | grep LCD
3) Edit the appropriate LCDd.conf config file located in accordance with ps | grep LCD output to put necessary preferrences to correct display section
4) Reboot LE again and then install and configure the XBMC LCDproc add-on properly.
I don't have any experience with Cfontz display as I am using hd44780 connected through i2c but I believe it should work fine as well.
You can also run the LCDd in foreground to test quickly with any preferred config file but make sure you don't run more instances at the same time.
Yes as you can see in your PS output there's the -d hd44780 parameter which forces this driver to be used (see the comments at beginning of LCDd.conf file regarding to -d parameter).
Change that in LCDproc add-on Configuration settings first to use another (CFontz or whatever you like) instead of default hd44780 driver.
Hopefully it's not a feature of Kodi 19.0-BETA1 as the screenshot filename's structure has been changed a bit but I couldn't find more info / fresh documentation related.
Action taken while TV playing:
kodi-send --action="Screenshot"
or
kodi-send --action="TakeScreenshot"
or invoked by keyboard (CTRL+S or PrtScr)
The screenshots are made in /storage/screenshots/ folder but...
Currently the Screenshot / TakeScreenshot action does not put the active video frame snapshot to .png file, just the Kodi's active GUI menu or a just black page if no menu is active.
Screenshot names are now starting from:
screenshot00000.png
Everything worked as expected (and documented) in LE 9.2.6 official with Kodi 18.9.0 - if the Screenshot was taken, there's a picture frame (combined with active Kodi GUI menu ) saved to .png file.
Screenshot names were starting from:
screenshot000.png
So you need to edit the [hd44780] section in /storage/.kodi/userdata/addon_data/http://service.lcdd/LCDd.conf to match your specific UART display's HW.
You may also find some info here:
Run this command to see what's the path to current LCDd.conf:
ps | grep LCD
You should see there something like:
LCDd -f -c /storage/.kodi/userdata/addon_data/http://service.lcdd/LCDd.conf -d hd44780
I have found some How To's and tried to create .pls and .strm files to be opened from Videos menu. Unfortunately so far I couldn't finish that simple task succesfully. 
The stream (MJPG 640x480, Planar 4:2:2 YUV full scale) is produced by ESP32CAM module using this source code: esp32-cam-mjpeg-multiclient/esp32_camera_mjpeg_multiclient.ino at master · arkhipenko/esp32-cam-mjpeg-multiclient · GitHub
It works fine with Firefox, Chrome, Edge and VLC but no way from Kodi.
Files tested:
cam1.pls
[playlist]
NumberOfEntries=1
File1=http://192.168.35.201/mjpeg/1
Title1=IP Camera
cam1.strm
Debug log when tried to open first the cam1.pls and then cam1.strm file:
Am I doing something wrong or there's a bug?
Thanks for the reply. Yeah but even the display clone I can't achieve on LE 9.80 - the display content is cloned when LE starts (the LibreELEC logo displayed on both ) until Kodi is initialitzed - then the secondary display is blanked out (regardless the Blank other displays settings) until Kodi is stopped - then the LE logo is again visible on both displays.
FYI this is info from Raspberry OS on the same HW:
export DISPLAY=:0.0
xrandr
xrandr
Screen 0: minimum 320 x 200, current 3840 x 1080, maximum 7680 x 7680
HDMI-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 160mm x 90mm
1920x1080 60.00*+ 50.00 59.94 30.00 25.00 24.00 29.97 23.98
1920x1080i 60.00 50.00 59.94
1600x1200 60.00
1680x1050 59.88
1280x1024 75.02 60.02
1440x900 74.98 59.90
1280x960 60.00
1280x800 59.91
1152x864 75.00
1280x720 60.00 50.00 59.94
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
720x576 50.00
720x480 60.00 59.94
640x480 75.00 72.81 66.67 60.00 59.94
720x400 70.08
HDMI-2 connected 1920x1080+1920+0 (normal left inverted right x axis y axis) 1150mm x 650mm
1920x1080 60.00*+ 50.00 59.94 30.00 25.00 24.00 29.97 23.98
1920x1080i 60.00 50.00 59.94
1280x1024 60.02
1360x768 60.02
1280x720 60.96 60.00 50.00 59.94
1024x768 60.00
800x600 60.32
720x576 50.00
720x576i 50.00
720x480 60.00 59.94
640x480 60.00 59.94
720x400 70.08
I know this question repeats now and then and looks even Kodi 19 BETA1 still does not support more than 1 display on this platform.
But I wonder if any developer could share some information what's the current status regarding this matter please? What is possible and what is not possible and why? Whay does and what does not make sense to try?
The goal for me in future is to use HDMI0 for LE / Kodi and HDMI1 to display IP camera(s) stream(s). Currently I am trying to get Kodi working on preferred HDMI port when there are 2 displays connected.
I have discovered that Kodi in LE 9.80 succesfully switch to HDMI port where the display is connected at boot if there's just 1 display connected. So HDMI1 can be used this way. But if both HDMI ports are occupied, always HDMI0 is used.
Is there any other way to force Kodi to use HDMI1 port instead default HDMI0 without cable detaching? The Monitor option is missing on Kodi Settings / System / Display page, playing with guisettings.xml did not help so far to overcome the default output to HDMI0.
On LE 9.2.6 using tvservice app (not useable anymore on LE 9.80) I was somehow able to get video displayed on HDMI1 even after boot when HDMI0 was active but there's no way to do the same on LE 9.80.
Struggling with config.txt in accordance with post Rpi4 - switching between different resolution HDMI outputs with one click also did not help.
xrandr does not work on LE 9.80 (yet?).
Could somebody informed give a comment please?
If you connect a display only to HDMI 1 port and upgrade to LE 9.80 nightly, Kodi will work - both audio and video goes to HDMI 1 automatically. When 2 monitors are connected, on both HDMI 0 and HDMI 1, Kodi works on HDMI 0 only.
So it should be yet possible to switch between HDMI 0 and HDMI 1 but I don't know what to configure. In Kodi / Settings / System / Display the option Monitor is missing even though I tried to play with the ~/.kodi/userdata/guisettings.xml modification, so far I failed to get the Kodi working with preferred HDMI port when both HDMI ports are occupied.
Also tried to modify the /flash/config.txt in accordance with this post Rpi4 - switching between different resolution HDMI outputs with one click but so far not succesfully.
Audio output on RPi 4B's HDMI1 works yet on LE 9.80 nightly.
