You need to update to ‘staging’. To test this update:
- Login via the command line
- Edit the file
- Add the following line:
deb http://apt.osmc.tv stretch-devel main
- Run the following commands to update:
sudo apt-get update && sudo apt-get dist-upgrade && reboot
- Your system should have have received the update.
Login again and type
echo 1 | sudo tee /sys/class/amhdmitx/amhdmitx0/force_hdr
Play some HDR material and see if your TV reports that it’s receiving HDR (it should say HDR or PQ).
I also recommend you edit
/etc/apt/sources.list again and remove the line that you added after updating. This will return you to the normal update channel.