No Audio Passthrough / HDMI Device not recognized (RPI4 LibreELEC 10.0.2)

Hello LibreELEC Community,

I need your help:

LibreELEC 10.0.2
Raspberry PI 4B

Denon AVR-X1700H DAB

Samsung TV (1080p)

I've installed LibreELEC 10.0.2 (clean install, no update) and at first I got no HDMI signal at all. (Yes, used the port next to the usb c connector)

With video=HDMI-A-1:1920x1080M@60 in the commandline I got a picture and the right resolution, but no sound. (Greyed out Audio Device Selection and only PulseAudio, Bluetooth)

Interesting: LibreELEC 9.8.2 works with no problems. Even Audio Passthrough with DTS and so on..

I tried the following in the config.txt:

hdmi_ignore_cec_init=1

hdmi_force_hotplug=1

hdmi_force_edid_audio=1

hdmi_group=1

hdmi_mode=16

hdmi_drive=2

in different combinations. No sound at all..

What works is

dtparam=audio=on

and suddenly I'm able to select the audio device ALSA bcm2835 HDMI 1..

..but no Passthrough and the sound has some "clicking" noise when I play a movie.

So I thought: Okay, I try to get it to work without these "workarounds" above.

Used the getedid command to read the edid but the file was empty.

tvservice gave me the following results:

1 attached device(s), display ID's are :
Display Number 2, type HDMI 0

Group CEA has 4 modes:
           mode 4: 1280x720 @ 60Hz 16:9, clock:74MHz progressive
  (prefer) mode 16: 1920x1080 @ 60Hz 16:9, clock:148MHz progressive
           mode 95: 3840x2160 @ 30Hz 16:9, clock:297MHz progressive
           mode 97: 3840x2160 @ 60Hz 16:9, clock:594MHz progressive

Group DMT has 1 modes:
           mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive

Audio:
     PCM supported: Max channels: 8, Max samplerate: 192kHz, Max samplesize 24 bits.
     AC3 supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
   MPEG1 supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
     MP3 supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
   MPEG2 supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
     AAC supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
     DTS supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
   ATRAC supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
     DSD supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
    EAC3 supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
  DTS_HD supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
     MLP supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
     DST supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
  WMAPRO supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.
Extended supported: Max channels: 8, Max samplerate: 192kHz, Max rate 2040 kb/s.

It seems without the config.txt "workarounds" LibreELEC doesn't find a HDMI device itself. (Yes, turned everything on before booting)

Has anyone any ideas whats wrong?

Quote from yapa69

hello

Did you try ?

rpi4 HDMI0 > TV

rpi4 HDMI1 > AVR

Hello Yapa.

You mean with two Hdmi cables?

No, but i could give it a try.

Display More

Quote from popcornmix

Forget about config.txt hdmi_* settings - they apply to the old firmware display driver that is not longer used.

Your symptoms suggest an issue with the edid.

Run:

Code

edid-decode /sys/devices/platform/gpu/drm/card0/card0-HDMI-A-1/edid

and check that produces output and contains an "Audio Data Block" section. Post output here.

Thanks for your reply. The file is empty and I get:

EDID extract of '/sys/devices/platform/gpu/drm/card0/card0-HDMI-A-1/edid' failed: unknown format.

Oh and if I remove all the "workarounds" from the config.txt and commandline the picture reverts to 640x480 and the max resolution in the settings are 1280x720, and no audio, audio device selection greyed out.

The only way to get 1080p is via commandline: video=HDMI-A-1:1920x1080M@60
(Also annoying: Powering off the AVR and on and I have to restart LibreELEC to get a picture again.)

To get audio working in config.txt: dtparam=audio=on

And then I'm able to select ALSA: bcm2835 HDMI 1 for audio, but then there's no option for AudioPassthrough and the sound has this "clicking" noise. In some movie scenes louder, in others barely noticeable, doesn't matter which content: stereo, dolby surround, dts...

My LibreElec 9 on seperate sd card works with all those options (PI: HDMI), and perfect sound. But I would like to update to LibreElec 10.

Thanks, I tried to connect it directly to the TV, tried the 2nd HDMI Port, different HDMi cables.. No luck so far.

And if it‘s a problem with the cable or the AVR, why does it work in LibreElec 9.2.8 then?

I ordered a new 8K HDMI 2.1 cable and I‘ll test it with it when it arrives. But I don‘t think it‘ll change anything.

Okay, with the new HDMI Cable everything works as it should. Interesting. Never thought it would make such a difference.

Thanks a lot for your help and suggestions!

For others with the same problem. This one works without problems:

CSL - 8k Micro HDMI auf HDMI 2.1... https://www.amazon.de/dp/B08SY86HGP?ref=ppx_pop_mob_ap_share