HDMI Passthrough - actual AVAILABILITY / DTS-HD Legacy break ???

tuhajbej6 · November 17, 2020 at 3:34 PM

For many different set top boxes: This particular setting that annoys numerous of LE users IS AVAILABLE but NOT IMPLEMENTED.

Why is this setting Available in so many LE machines when actually it is not working - what is more inconvenient - when this setting is NOT TESTED - then the noise may destroy home cinema speakers or at least shock the user.

Suggesting posting HDMI Passthrough reports in this Thread for developers and testers' convenience. How about gathering the devices and chipset down here and show if it's reasonable to disable the HDMI passthrough option in a release when it is not working ot not fully tested.

Why it is not being tested ??

In many boxes - especially this setting - is just abandoned for "students".....Why is that ??

As an example - my RK3399 RockPi4 box HDMI Passthrough is totally left aside while there where AndroidTV implementations already successfull. How can I find dev group for I could ask for HDMI Passthrough implementation in LibreElec ?? Please advice.

cheers,
Asia

hervald · November 17, 2020 at 8:36 PM

Hi,

I've just spent days to find a solution to the passthrough problem for my nanopi m4. And I finally found a fork of libreelec taht works just fine :

Release 9.2.2-rk3399 update · Joern-P/LibreELEC.tv · GitHub

I tested the .img on an sdcard and emmc and all is ok. In order to boot correctly for the nanopi m4, I jsut changed the .dtb. For that :

- download rk3399-nanopi4-rev01.dtb

- plug in the sd card

- wait for it to mount, udner linux you obtain to mount point : /media/mylogin/LIBREELEC and /media/mylogin/STORAGE

- copy rk3399-nanopi4-rev01.dtb in /media/mylogin/LIBREELEC

- go to /media/mylogin/LIBREELEC/extconf and modify the file here to change the name of the dtb file.

With that, I succeed in getting HDMI passthrough in kodi. For that, i set kodi with :

- in audio settings :

- enable passthrough + aC3 passthrough + dts passthrough (my AVR seems to be unable to manage EAC3)

- change the number of channels to 5.1

- when playing a video with 5.1 AC3/DTS : press enter then go to the parameter icons and in the audio parameters, choose enable passthrough. Then my AVR recevies effectively the AC3/DTS signal directly and decodes it.

- when playing a video with EAC3 : press enter then go to the parameter icons and in the audio parameters, choose disable passthrough. Then my AVR receives PCM 5.1 because I set kodi to sends audio in 5.1.

So, everythings fine for the nanopi m4.

Now for rockpi4, it is possible that you can use the same image but using the dtb for the rockpi4, doing the same mods I did. It might work because the kernel settings are normally the same (as far as I understand correctly the building process of libreelec) but the dtb changes.

So, let's try