Pretty sure Emby is open source since Jellyfin is a fork of it, but that also means you might run into the same issues if you try switching over.

I’d check if you have hardware transcoding turned on. If you have an intel cpu it should be enough to get things to work.

Left to right, top to bottom: Mastodon, PeerTube, Pixelfed, Nextcloud, Lemmy And they all correspond to the apps in the same spots on the bottom.