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:[email protected] 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:



    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?

  • 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.

  • 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:


    Code
    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:[email protected]
    (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.

    Edited 2 times, last by Euphonique ().

  • Connect the RPi4 directly to the TV (no AVR) and check the EDID data is readable. If it is, capture the EDID from the TV to file so it can be forced to workaround the issue the AVR is introducing. If it is not (and do this anyway..) try different HDMI cables.

  • 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.