i also have to set virtual desktop video player settings to use direct3d 11 acceleration too.
"If you are on the latest Windows 10 Fall Creators Update, make sure to download the HEVC Video Extension to get the best hardware decoding performance. It used to be part of Windows but is now a separate download, from the microsoft store."
i installed the klite codec pack and set h.265 decoder to lav in "preferred decoders" tab using the tweak tool in the klite software.
i just set everything to use lav in the "preferred decoders" tab though."