You only need a single 12-24V power supply to power the Raspberry Pi and the Amp4. With 4 Ohm speakers, we recommend 12-20V. Higher operating voltages are only recommended with 8 Ohm speakers.
What's the power supply of your RPi / HiFiBerry system? Maybe you don't get enough wattage for A/V.
Hmm, then other users should answer. 
Ask your Windows support team.
Better use EXT4 as your file system.
The WiFi data rate seems to be the problem (A/V goes out-of-sync):
2024-10-29 20:48:30.709 T:1060 debug <general>: ActiveAE::SyncStream - average error of 29.588072, start adjusting
2024-10-29 20:48:30.709 T:1060 debug <general>: ActiveAE::SyncStream - average error 0.588072 below threshold of 30.000000
2024-10-29 20:48:31.815 T:1060 debug <general>: ActiveAE::SyncStream - average error -220.747135 above threshold of 100.000000
2024-10-29 20:48:32.303 T:1060 debug <general>: ActiveAE::SyncStream - average error -20.747135 below threshold of 30.000000
2024-10-29 20:48:33.063 T:1060 warning <general>: ActiveAE - large audio sync error: -1485.769446
2024-10-29 20:48:33.065 T:1060 warning <general>: ActiveAE - large audio sync error: -1485.769279
2024-10-29 20:48:33.356 T:1060 warning <general>: ActiveAE - large audio sync error: -1685.723723
2024-10-29 20:48:33.356 T:1060 debug <general>: ActiveAE::SyncStream - average error -963.297485 above threshold of 100.000000
2024-10-29 20:48:33.398 T:1394 info <general>: CVideoPlayerAudio::Process - stream stalledI agree with VLouis . The RPi WiFi is known to be weak. You could buy a USB-to-WiFi, or Ethernet-to-WiFi adapter.
Before buying anything, I would try an Ethernet connection to the Odroid server. Maybe the WiFi is fine, but Odroid can't deliver higher data rates.
This has nothing to do wtih what i asked. I asked though LE, not using extra hardware.
I know, that's why I said "BTW". Extra hardware is the most reliable way to make it work.
Is it possible to change "<power>shutdown</power>" --> "<power>reboot</power>" without quotes instead?
Yes.
It mirrors the whole display, so it's not related to Kodi, and no Kodi support is needed.
You need a Miracast receiver device, like a Miracast TV or an HDMI adapter. Also make sure to have the right Android version.
What exactly you mean? Can i just use Miracast somehow? I dont understand
It's AirPlay for Android. It's a screen mirroring service, directly provided by Android OS. Google it, that's not our turf.
BTW: The Android implementation is called Miracast. Together with the Kodi app it might work for you.
...format the external USB HDD to one of linux partition formats (which one?)...
Yes, "Linux" partition type, and an "EXT4" file system on top of it.
...keep an extra laptop with a Linux distro, in case RPi fails, so I can plug the HDD to that laptop and copy necessary files, I may need, so I can use them under windows.
That's not necessary. A USB stick with a Linux "Live" distro can boot on a Windows PC. I guess there are also Windows programs for EXT4 access.
Not possible.
Very unlikely. Try to build your own driver.
How can I check if it's smb share or something else?
Your file content is missing a slash. It has to look like this:
<advancedsettings version="1.0">
<video>
<maxtempo>1.5</maxtempo>
</video>
</advancedsettings>Because the value range starts at 1.5, it probably doesn't work with lower values, and doesn't solve the problem.
Of course you can try other options, like playing with frame rates. Personally I would try the <fpsdetect> options next. Kodi is no professional video production software, so we don't have measurement for perfect playback speed. You have to experiment.
The A/V are in sync but sped up.
I see, in-sync has a different meaning in my world. Reduce the <maxtempo> value then.
dipswitch Of course it goes into the next stable release. Use nightly builds meanwhile. No ETA, as always.
Sorry for any problem that I've cause, but it is not legal to ask for help to just install the transmission service con my LibreElec?
It's legal, but due to the amount of illegal misuse we don't support it.
