Send url from firefox tab to mpv ipc
1. Download
2. Open in firefox about:debugging
3. Click on "Load Temporary Add-on..."
4. Find manifest.json
5. In terminal ./start.mpv.ipc.server.sh
Context menu on video url: Url2Mpv->loadfile or Url2Mpv->append-play.
Open youtube video and press Ctrl+Shift+Space or Alt+Shift+Space for append/start mpv playlist.
Click button in ff bar.