Hi,
up until now I had my RP4 with LibreELEC 12.0.2/KODI 21.2.0 connected via HDMI0 to my AVR and everything was working fine (everything being MKVs from my DVDs and Blu-rays; mpeg-2, vc-1 and h264).
A few days ago I added my first video files with HDR (MKVs from my UHDs; h265) and noticed that my AVR (Onkyo TX-SR444) was not able to passthrough HDR material to my TV. I tried connecting my RP4 directly to the TV which gave me HDR but the ARC from the TV to the AVR wasn't able to passthrough Dolby-HD/Dolby Atmos etc. That's when I decided to buy another HDMI cable (cheaper than buying a new AVR) and connect my RP4 to my TV on HDMI0 and to my AVR on HDMI1.
I changed the settings to output decoded audio to the TV (mainly KODI's menu sounds) and passthrough PCM to the AVR.
When I watch "non-HDR/not UHD-based/mpeg-2, vc-1 and h264 movies" I have no problems. (I had some problems with a Blu-ray-based movie with Atmos sound but that went away after some restarts...)
When I start playing a HDR/UHD-based/h265 movie the sound will start playing back via the AVR (Atmos indicator lighting up correctly) until a change to the picture happens (e.g. I use the remote to open a menu or the first subtitle gets displayed). That's when the audio stops and won't come back (for any movie) until I restart the RP4.
Has anyone encountered similar problems?