Error:if: Symbol??s function definition is void: emms-player-mpv-ipc-fifo-p

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Hi there,I want to use emacs emms to play music file and youtube url,and I have emms configuration below,but when I execute M-x emms-play-file it can not work and show message "if: Symbol??s function definition is void: emms-player-mpv-ipc-fifo-p",I hope someone can tell me how to config emms using mpv correctly,thanks

```

use-package emms
  :ensure t
  :config
  (add-to-list 'exec-path "~/.emacs.d/download-package/")
  (require 'emms)
  (require 'emms-setup)
  (require 'emms-player-mpv)
  (emms-all)
  (emms-default-players)
  (if(eq system-type 'windows-nt)
      (progn
    (setq emms-player-list '(emms-player-mpv)
          emms-info-functions '(emms-info-native))
    (setq emms-player-mpv-command-name "~/Nutstore Files/Program/emacs-exec-path/mpv.exe")

    ;; (add-to-list 'emms-player-list 'emms-player-vlc)
    ;; (setq emms-player-vlc-command-name "~/Nutstore Files/Program/emacs-exec-path/vlc.exe")
    )    
    (progn
      (setq emms-player-list '(emms-player-mpv)
        emms-info-functions '(emms-info-native))
      (setq emms-player-mpv-command-name "/usr/bin/mpv")
      ;; (add-to-list 'emms-player-list 'emms-player-vlc)
      ;; (setq emms-player-mpv-command-name "/usr/bin/vlc") 
      )
    )
  )

```

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