[KoStein]

To my knowledge in the Raspberry Pi version of Kodi Leia 18.3 (installed on top of LibreELEC Leia 9.2 ALPHA1) the Pi's (RPi 4) hardware h265-video-decoder is utilized.
I would also like to use the Pi's hardware h265-video-decoder for my own C++ project. Since at this point there is no official information/documentation available on how to access this decoder, I try to find out how it's done in Kodi.

Unfortunately I was unable to locate code responsible for accessing the mentioned decoder by studying "https://github.com/xbmc/xbmc".
May someone please guide me to the right place to take a closer look on how the hardware h265-decoder of the Raspberry Pi 4 has been accessed.

Hope it's not too much to ask for?!
Thanks!

[Milhouse]

I try to find out how it's done in Kodi.

LibreELEC 9.2 for RPi uses a RPi vendor version of Kodi:
https://github.com/popcornmix/xbmc/tree/..._18.3-Leia

This vendor version of Kodi adds a number of RPi specific ffmpeg patches:
https://github.com/popcornmix/xbmc/tree/...get/ffmpeg

The pfcd_hevc_optimisations patch implements the RPi2/3 HEVC support.

For RPi4 HEVC hardware support you want the pfcd_hevc_optimisations patch from this RPi4 branch:
https://github.com/popcornmix/xbmc/tree/...get/ffmpeg

You can also look at the LibreELEC repository to see the changes that were necessary to support Kodi 18.3 on RPi4.

Bear in mind that as your own C++ project is not likely to be Kodi related if you need more technical help you might be better off opening an "RPi4 HEVC hardware decode" thread on the Raspberry Pi forum (assuming there isn't one already).