No audio on HDMI from new Pi4b..... a common prob. it seems.

    Hello ladies and gentlemen. Thanks for the opportunity to post. Please bear with me as I paste my post to the Kodi forum. I see there was once a response here to this problem but I would be really grateful for the latest news on this topic and any new ideas on a fix or workaround.

    The new Pi4 does not play audio (as did the Pi3) through the No. 1 micro HDMI to the home theatre receiver... only video. I see online this is also a problem for people plugging straight into various tvs. And the No.2 port plays neither video or audio.


    Someone in a Librelec forum posted this fix, but I haven't tried it. I will paste it below. But I would really like to hear from any forum members who have solved this in some way. And if no one has, well, just don't waste your money on the buggy Pi4 I guess.


    Thanks. I have a feeling I will reinstate my Pi3


    (and for the fix below, what is going on with the drive 2 setting? What drive?)


    Sep 8th 2019


    #4


    I solved it with hdmi_drive=2


    For anyone else who comes across this issue here's how to make the setting change. You need to have ssh enabled, then from another computer ssh to the libreelec box (replace ”libreelec” with the name of your box):


    ssh root@libreelec



    Then:


    mount -o remount,rw /flash


    nano /flash/config.txt



    And add the line:


    hdmi_drive=2



    Ctrl+o to save and Ctrl+x to exit nano. Reboot and it should all work. You should also consider adding the line:


    hdmi_force_hotplug=1



    Which will ensure HDMI is used even if unplugged or the TV is off when the libreelec box is turned on.

    RPi4b 4GB + LibreELEC-RPi4.arm-9.1.501.img.gz

    I added the two lines described above to setup.txt, which did solve the "no audio"-problem I experienced.

    I was getting sound some of the time. I rebooted with a number of different options (no hdmi connected initially, connected all the time). Sometimes it would still work after a reboot.

    I have a Panasonic ST60 TV and was using 1024x768 resolution since 1920 wasnt working.

    Code
    hdmi_group=2
hdmi_mode=16

    When I added the line below sound was working as expected:

    Code
    hdmi_drive=2

    This is actually the correct functionality. There are two video outputs, and two audio outputs. The normal behaviour is for the audio to be sent to the first output, on HDMI0. You wouldn't ordinarily send the same output to two different output channels, so HDMI1 is unused. I think there might be an option you can add to cmdline.txt to treat them as a single output.