I am using latest nightlies on rpi4 where as far as know for all devices the following is still a good overall reference.
Audio quickstart guide - Official Kodi Wiki
Note: Set your audio setting as per the "AVR HDMI (HD Audio)" column.
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.
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.
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.
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)
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.
