chickadee » mpd-client

mpd-client

Interface to the Music Player Daemon.

Documentation

This extension allows convenient access to the tcp interface of MPD.

Connecting to MPD and obtaining connection/server information

(connect [HOST] [PORT] [PASSWORD])procedure

Connects to the MPD instance running on HOST (defaults to localhost) at PORT (defaults to 6600). Optionally authenticates using PASSWORD. Returns an MPD connection object.

disconnect CONNprocedure

Closes the connection to MPD. CONN should not be used anymore after calling this function.

mpd-connection? CONNprocedure

Returns #t if CONN is an MPD connection object, #f otherwise.

mpd-host CONNprocedure

Returns the hostname field of the MPD connection object CONN.

mpd-port CONNprocedure

Returns the port field of the MPD connection object CONN.

mpd-password CONNprocedure

Returns the password field of the MPD connection object CONN. This is either a string containing the plain text password or #f if no authentication should be done.

mpd-version CONNprocedure

Returns the version field of the MPD connection object CONN which contains the version number received by the MPD server.

ping CONNprocedure

Sends a ping command to the MPD server, reconnecting if necessary.

clear-error! CONNprocedure

Clears the current error message (which is returned by (get-status)). This is also done by any command that starts playback.

get-stats CONNprocedure

Returns an alist containing various stats:

#;6> (pp (get-stats m))
((artists . 183)
 (albums . 429)
 (songs . 6200)
 (uptime . 130260)
 (playtime . 49958)
 (db_playtime . 1773229)
 (db_update . 1152376960.0))
#;7>
get-status CONNprocedure

Return an alist describing the current status of MPD:

#;9> (pp (get-status m))
((volume . 78)
 (repeat . #f)
 (random . #f)
 (playlist . 78)
 (playlistlength . 77)
 (xfade . 0)
 (state . play)
 (song . 12)
 (songid . 12)
 (time 31 623)
 (bitrate . 128)
 (audio 44100 16 2))
#;10>
shutdown-server! CONNprocedure

Kill MPD.

get-commands CONNprocedure

Returns a list of commands the current user has access to.

Controlling playback

play-song! CONN #!optional SONG TIMEprocedure

Start playing at song SONG (or the first in playlist) at TIME (in seconds).

next-song! CONNprocedure

Play the next song in the playlist.

previous-song! CONNprocedure

Play the previous song in the playlist.

stop! CONNprocedure

Stop playback.

pause! CONN PAUSE?procedure

Pause if PAUSE? is true, resume playing otherwise.

set-options! CONN #!rest OPTSprocedure

Set playback options. Options are: #:crossfade, #:random, #:repeat and #:volume and they can be mapped to arguments.

Managing output devices

get-output-devices CONNprocedure

Returns a list of alists describing the available output devices.

enable-output-device! CONN IDprocedure

Enables the output device with id ID.

disable-output-device! CONN IDprocedure

Disables the output device with id ID.

Querying and modifying the current playlist

get-playlist CONN #!optional IDprocedure

Return a list of alists describing the songs in the current playlist. (Optionally only the song with id ID):

#;10>  (pp (get-playlist m 12))
(((Id . 12)
  (Pos . 12)
  (Time . 623)
  (Title . "the leper affinity")
  (Track . 1)
  (Album . "blackwater park")
  (Artist . "opeth")
  (file . "metal/opeth/blackwater park/01 the leper affinity.mp3")))
#;11>
get-current-song CONNprocedure

Returns an alist with information about the current song (the same information that (get-playlist) returns).

get-playlist-changes CONN VERSIONprocedure

Return a list of alists describing new songs since playlist version VERSION. Note: to detect songs that were deleted at the end of the playlist, use the playlistlength returned by (get-status).

add-song CONN PATHprocedure

Adds PATH (a string naming a file or directory) to the end of the current playlist. Directories are added recursively. Increments playlist version by 1 for each added song.

move-song! CONN FROM TOprocedure

Move song at position FROM to TO. The playlist version is incremented by 1.

swap-songs! CONN SONG1 SONG2procedure

Swap position of the two songs.

remove-song! CONN SONGprocedure

Remove the song SONG (position or ID) from playlist. The playlist version is incremented by 1.

shuffle-playlist! CONNprocedure

Shuffles the current playlist and increments the playlist version by 1.

clear-playlist! CONNprocedure

Clears the current playlist, incrementing playlist version by 1.

Managing stored playlist

load-playlist! CONN PLAYLISTprocedure

Loads the playlist named "PLAYLIST.m3u" from the playlist directory. The playlist version is incremented by the number of songs added.

remove-playlist! CONN PLAYLISTprocedure

Removes the playlist named "PLAYLIST.m3u" from the playlist directory.

save-playlist! CONN PLAYLISTprocedure

Saves the current playlist to "PLAYLIST.m3u" in the playlist directory.

Querying/Updating song database

find-songs CONN TYPE STRINGprocedure

Searches for songs and returns a list of alists. TYPE is e.g. 'title, 'album or 'artist. STRING is the search string (which must match exactly).

search-songs CONN TYPE SEARCHSTRINGprocedure

Returns a list of alists describing the matching songs. TYPE is e.g. 'title, 'album or 'artist. SEARCHSTRING is the string which is searched for (not case sensitive, doesn't need to be an exact match).

(list-metadata CONN TYPE [LIMIT STRING])procedure

Return a list of values of metadata TYPE (e.g. 'title, 'album or 'artist), optionally limited by LIMIT and STRING. E.g. (list-metadata m 'album 'artist "nevermore") to get a list of all albums by Nevermore.

(list-directory/r CONN [PATH] [FULL #t])procedure

Returns a list of all songs (below PATH, if given). If FULL is #t (default), list all metadata. If FULL is #f, return only filename metadata.

list-directory CONN #!optional PATHprocedure

Like (list-directory/r), with FULL as #t. The data is returned as a list of alists.

update-song-database! CONN #!optional PATHprocedure

Updates MPD's database, removing old songs and adding new songs. Optionally, the update process can be limited to PATH (a string naming a file or directory).

Examples

#!/usr/local/bin/csi -script

(require-extension mpd-client srfi-18 utils)

(define mpd (connect))

(define (get-mpd-status)
  (let ((status (get-status mpd)))
    (list (alist-ref 'songid status)
          (alist-ref 'state status))))

(define (get-songname id)
  (let ((info (car (get-playlist mpd id))))
    (or (alist-ref 'Title info)
        (pathname-strip-directory
         (alist-ref 'file info)))))

(let loop ((status (get-mpd-status)) (old-status #f))
  (unless (equal? status old-status)
    (let ((song (car status))
          (state (cadr status)))
      (cond
       ((eq? state 'play)
        (printf "Now playing: ~a\n"
                (if song
                    (get-songname song)
                    "(unknown song)")))

       ((eq? state 'stop)
        (printf "STOP\n")))))
  (thread-sleep! 1)
  (loop (get-mpd-status) status))

About this egg

Author

Hans Bulfone

Version history

1.12
Added regex as a dependency; converted eggdoc documentation to wiki format [Ivan Raikov]
1.1
Added new commands supported by recent versions of MPD
1.02
Fixed a bug that caused playlists to be returned incorrectly by mpd:ls/info et al.
1.01
Fixed typo in documentation
1.0
Initial release

License

Copyright (c) 2006-2007, Hans Bulfone
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of the author nor the names of his contributors may
      be used to endorse or promote products derived from this software
      without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Contents »