Mpv – A free, open source, and cross-platform media player
If you use jellyfin jellyfin-mpv-shim lets you play streams in mpv without worrying about transcoding.https://github.com/jellyfin/jellyfin-mpv-shimOther fun tricksIf you use jaro instead of xdg-open you can make video links automatically open in mpv while regular web links open in your browser of choice.https://github.com/isamert/jaroIf you use elfeed its nice to watch video entries in mpv without a side trip to  the browser. Stolen from Prot somewhere or other.  (defun prot/elfeed-mpv-dwim ()
  "Play entry link with external `mpv' program.
  When there is an audio enclosure (podcast), play just the audio.
  Else spawn a video player at a resolution that accounts for the
  current monitor's width."
  (interactive)
  (let\* ((entry (if (eq major-mode 'elfeed-show-mode)
   elfeed-show-entry
   (elfeed-search-selected :ignore-region)))
  (link (elfeed-entry-link entry))
  (enclosure (elt (car (elfeed-entry-enclosures entry)) 0)) ; fragile?
  (audio "")
  ;; Here the display width checks if I am on the laptop
  (height (if (<= (display-pixel-width ) 1366) 720 1080))
  (video (format "--ytdl-format=bestvideo[height<=?%s]+bestaudio/best" height))
  ;; (buf (pop-to-buffer "*elfeed-mpv-output*"))
  )
  (run-hooks 'prot/elfeed-mpv-hook)
  (if enclosure              ; make this its own parametrised function
  (progn
   (start-process "f fuckoff audio-mpv" nil "mpv"  enclosure)
   (message (concat "Launching MPV for " (propertize enclosure 'face 'success))))
  (start-process "f fuckoff video-mpv" nil "mpv" video link)
  (message (concat "Launching MPV for " (propertize link 'face 'success))))))

At one point I wrote script to prompt for a name if passed more than one argument and create a playlist and remember the last n playlists and regular files opened so you could in turn pull up this list and narrow with rofi but as of late I'm just adding videos to jellyfin.Umpv is a script that emulates single instance mode whereby arguments are simply pushed to the existing players playlist instead of opening a new player.https://github.com/mpv-player/mpv/blob/master/TOOLS/umpv