RK3229 box - can not select SPDIF as passthrough device.

  • Hello,

    I am trying to set up a MXR 4K box with a RK3229 chip,

    I am running community build LE9.20 (Kodi 18.5)

    I have a Logitech Z-5450 Speaker/amp set with Dolby Digital (AC3) and DTS support with SPDIF optical and Coax input

    I also have a Samsung LCD (2011)


    The problem is getting passthrough to work with my SPDIF (COAX) out.

    In the audio devices I can select SPDIF and by doing so I can get stereo to work (because the Kodi transcode's the audio to PCM and with SPDIF coax that means I only get two channels (stereo)

    The problem is that , at the passthrough options I can NOT select another device (greyed out) also , changing the Audio device itself does NOT change anything at passthrough.

    When I enable passthrough now and use my Samsung LCD also to passthrough I can get Dolby Digital to work (goes from Kodi HDMI to my Samsung and than passthrough to the optical SPDIF from my logitech (say's Dolby Digital than)

    I can sadly not use that methode for DTS because my samsung (like most TV's) wont passthrough DTS)

    What could be the reason I can not select my SPDIF as an output device for passthrough ?

    what would cause this to be greyed out ?

    I dont think there is anything wrong with the libreelec install since my SPDIF works as normal output device, and passthrough is also working for HDMI, I just cant select any other output for passthrough :(


    I am probably doing something stupid , so have fun pointing that out to me and help me out :) :) :)


    thank you,

    Hans

    Some screenshots ;

  • LibreELEC doesn't support passthrough for Rockchip devices.

    Ok, that explains alot :)

    Would be nice if the "passthrough" option would be greyed out than :(

    I am guesing it is do to missing rockchip drivers (from rockchip themselves) and wont be fixed until rockchip brings out drivers ??


    thank you for your answer.

  • LibreELEC doesn't support passthrough for Rockchip devices.

    But what does it mean for future ?
    1. no patch for LE is possible
    2. it is a matter of patching "rk3399-rock-pi-4.dtb"
    3. it is not hardware possible

    Please comment - this functionality is really awaited for as it changes sound experience vastly nowadays.

  • But what does it mean for future ?
    1. no patch for LE is possible
    2. it is a matter of patching "rk3399-rock-pi-4.dtb"
    3. it is not hardware possible

    Please comment - this functionality is really awaited for as it changes sound experience vastly nowadays.

    It is hardware possible.

    A LibreELEC developer just has to add a working patch for Rockchip devices, test it and build a new image.

    Eg. for Allwinner devices these patches add audio passthrough - Allwinner: WIP audio passthrough · jernejsk/LibreELEC.tv@87cbddb · GitHub

    So something similar with a few changes could work on Rockchip devices too.

    But they first want to improve video playback I heard so audio passthough will likely take the back seat for another couple of months unless independent developers can do tests and create a patch.

  • It is hardware possible.

    A LibreELEC developer just has to add a working patch for Rockchip devices, test it and build a new image.

    Eg. for Allwinner devices these patches add audio passthrough - Allwinner: WIP audio passthrough · jernejsk/LibreELEC.tv@87cbddb · GitHub

    So something similar with a few changes could work on Rockchip devices too.

    But they first want to improve video playback I heard so audio passthough will likely take the back seat for another couple of months unless independent developers can do tests and create a patch.

    Thanks for clarifying.

    I see it was commited in July.. So nobody willing took care of it yet for Rockchip?
    Not sure how the development goes - where can we put request in this case ?