sudo apt install vainfo libva2 i965-va-driver-shaders intel-media-va-driver-non-free -y

If your Linux Mint system lacks the correct decoding software, you will experience: Audio playing with a completely black screen. Media players throwing an "Unsupported Codec" error.

Reset VLC preferences:

Mastering High-Efficiency Playback: How to Install HEVC Codecs for MKV Videos on Linux Mint

Open a terminal window (press Ctrl + Alt + T ).

Add these lines to enable HEVC hardware decoding via VA-API:

Many Linux Mint media applications, including the default video player, are built on the GStreamer multimedia framework. Installing the GStreamer plugin for libde265 will enable HEVC playback across all these applications.

If you are still having issues with hardware acceleration or specific 4K HEVC files, you might need a more up-to-date version of the multimedia libraries than what is in the default repository.