Best audio passthrough setting for Rockchip 3328

1st Official Post

    Hi

    I need some help

    What is the best audio passthrough setting for Rockchip 3328 (Popcorn Hour Transformer) connected to Denon AVR-X2700H via HDMI Cable (2.1). supporting Sound formats Dolby Atmos, Atmos Height Virtualization, DTS:X, DTS Virtual:X . connected to my LG OLED 65-G7 TV

    I am using latest LibreELEC (Matrix) 10.0 BETA2

    regards

    Thanks, MikeKL,

    I did exactly as the Official guide says, but the TrueHD and DTS-HD are not working at all.

    Dolby Digital works fine also with Atmos😊 the DTS works sometimes but When I activate TrueHD and DTS-HD I get just noises.

    I know my box can handle alle this format, because when I use Kodi with Android the sound is fine (but the HDR is not working☹)

    I guess I must wait for the LibreELEC team to fix this some time I the future

    • Official Post
    Quote from HansRJ

    I did exactly as the Official guide says, but the TrueHD and DTS-HD are not working at all.

    High bandwith PT won't work - at least two drivers need to be extended and ALSA config must be changed accordingly. I created hackish experimental implementation for Allwinner, but I don't have knowledge about Rockchip internals to do the same for RK.

    Quote from HansRJ

    Dolby Digital works fine also with Atmos😊 the DTS works sometimes but When I activate TrueHD and DTS-HD I get just noises.

    as jernej mentioned there is no support for HBR audio in the upstream HDMI driver (yet) and I'm slidly suprised that it works on android, since vendor kernel doesn't seem to have that implemented as well.

    If your AVR support HBR audio via SPDIF, its worth a try to check if this works. (Note: Bitstream parsing is currently partly broken / unmaintainted on kodi side, which is propably the cause why DTS works only sometimes). There is also an part-fix for compressed audio pt which didn't make it into beta2 release - its available in current nightlies.

    I am using the Android TV 7.1 Community Build Image [eMMC] by ayufan image (android-7.1-rock-64-rock64_atv-v0.3.13-r115-raw.img.gz) and Kodi 19 from Google Play Store and all sound that I tried works perfect, but for some reason the HDR is not working.

    My box (Rockchip 3328 - Popcorn Hour Transformer) connected to my Denon AVR-X2700H via HDMI Cable (2.1), I will try to get an SPDIF cable and test how its work with latest LibreELEC .

    HansRJ

    You need Android 9/10 for working HDR playback and auto frame-rate support(which only a few RK3328 devices support)

    Here is the vendor kernel HDMI Bitstream passthrough commit

    drm: bridge/dw-hdmi: add support for hdmi bitstream audio · rockchip-linux/kernel@924f480 · GitHub

    Android 7(3.10 kernel), Android 9(4.4 kernel) & Android 10(4.19) kernel has fully working HBR Passthrough in Android Kodi 19.

    But it would probably not help for mainline kernel.

    jernej

    Is there any documentation or kernel sources that would be useful to you to understand how Rockchip devices work?

    There are some open-source devices like Rock64 & ROC-RK3328-PC with documentation and source-code available.

    Maybe hh @ rock-chips.com can help?(RK audio engineer, not sure if he still works there)

    • Official Post

    mo123 I know there is enough documentation and source code to implement this, but I would need to study how it works. It may or may not be easy to implement, but my focus are Allwinner SoCs, which I know well and although they work pretty well by now, there is still much to improve.