Part of macOS

`VTDecoderXPCService`Video decoding

○ Leave it

Decodes video for apps that play it.

What it is

Uses the Mac’s video hardware to play video for apps.

Why it might be busy

While video plays. Usually while it plays.

If you stop it

macOS starts it again straight away. Leave it.

○ Leave it. Part of macOS, or something that starts again by itself. You never need to close these.

From Procession’s guide, in the words the app shows.