Music Player Daemon/ヒントとテクニック

メインの記事は Music Player Daemon。

ライブラリの管理

MPD does not manage your library. Check out beets or picard in the official repositories.

Last.fm/Libre.fm scrobbling

ノート: mpd release 0.18 removed Last.fm support. However, some clients offer scrobbling independent of mpd.

To scrobble your songs to Last.fm or Libre.fm when using MPD, there are several possibilities.

mpdas

mpdas is an AudioScrobbler client for MPD written in C++. It uses curl and libmpd. mpdas supports the latest AudioScrobbler protocol (2.0) and will also cache unscrobbled plays in ~/.mpdascache if there's no network connectivity.

mpdas^AUR is available in the AUR.

Configuration of mpdas is very simple, see the official README. A very basic example of /etc/mpdasrc is also available as /etc/mpdasrc.

Your password can also be in the form of an md5hash:

echo -n 'PASSWORD' | md5sum | cut -f 1 -d " "

To autostart mpdas along with mpd, add an entry for it into the file in which you start mpd (e.g. xinitrc):

[[ -z $(pgrep -xU $UID mpdas) ]] && mpdas &

mpdcron

mpdcron is a cron-like daemon for MPD that listens for events and executes user defined actions. It can be extended via modules to show notifications, submit songs to Last.fm or Libre.fm (scrobbling), or to collect statistics about played songs.

mpdcron-git^AUR is available in the AUR.

See the official page for information about configuration and modules.

To autostart mpdcron along with mpd, add an entry for it into the file in which you start mpd (e.g. xinitrc):

[[ -z $(pgrep -xU $UID mpdcron) ]] && mpdcron &

mpdscribble

mpdscribble^AUR is a daemon available in the AUR (if you prefer, mpdscribble-git^AUR is also available). This is arguably the best alternative, because it is the semi-official MPD scrobbler and uses the new "idle" feature in MPD for more accurate scrobbling. Also, you do not need root access to configure it, because it does not need any changes to /etc at all. Visit the official website for more information.

After you have installed mpdscribble, do the following (not as root):

$ mkdir ~/.mpdscribble

• Create the file ~/.mpdscribble/mpdscribble.conf and add the following:

~/.mpdscribble/mpdscribble.conf

[mpdscribble]
 host = your mpd host # optional, defaults to $MPD_HOST or localhost
 port = your mpd port # optional, defaults to $MPD_PORT or 6600
 log = /home/YOUR_USERNAME/.mpdscribble/mpdscribble.log
 verbose = 2
 proxy = your proxy # optional, e. g. http://your.proxy:8080, defaults to none

 [last.fm]
 # last.fm section, comment if you do not use last.fm
 url = http://post.audioscrobbler.com/
 username = your last.fm username
 password = your last.fm password
 journal = /home/YOUR_USERNAME/.mpdscribble/lastfm.journal

 [libre.fm]
 # libre.fm section, comment if you do not use libre.fm
 url = http://turtle.libre.fm/
 username = your libre.fm username
 password = your libre.fm password
 journal = /home/YOUR_USERNAME/.mpdscribble/librefm.journal

Your password can also be in the form of an md5hash:

echo -n 'PASSWORD' | md5sum | cut -f 1 -d " "

• Add mpdscribble to the file in which you start mpd as well (e.g. ~/.xinitrc):

pidof mpdscribble >& /dev/null
if [ $? -ne 0 ]; then
 mpdscribble &
fi

systemd ユーザーサービス

以下のサービスを使うことで systemd のユーザーインスタンスで mpdscribble を起動することができます。詳しくは systemd/ユーザー を見て下さい。

~/.config/systemd/user/mpdscribble.service

[Unit]
Description=MPD Scribbler
Requires=mpd.service
After=mpd.service

[Service]
ExecStart=/usr/bin/mpdscribble --no-daemon

[Install]
WantedBy=default.target

Sonata

Sonata has built-in support for scrobbling, although that requires the program to run the whole time. Additionally, Sonata does not cache the songs if they cannot be forwarded to Last.fm at the time of playing, meaning they will not be added to the statistics.

起動時のレジューム再生を無効化

This feature is present in mpd after version 0.16.2. When this feature is enabled, mpd will always start in the "paused" state, even if a song was playing when mpd was stopped. Add the line below to your mpd.conf to enable this feature.

restore_paused "yes"

サンプル設定: Output with 44.1 KHz at e. g. 16 bit depth, multiple programs at once

Why these formats? Because they are the standard format for CD audio, because ALSA on its own allows more than one program "to sound" only with dmix — which uses an inferior resampling algorithm by default — and because dmix by default resamples anything lower to 48 KHz (or whatever higher format is playing at the time). Also, some get clicking sounds if at least mpd.conf is not changed this way.

What is the downside? These settings cause everything (if necessary) to be resampled to this format, such as material from DVD or TV which usually is at 48 KHz. But there is no known way to have ALSA dynamically change the format, and particularly if you listen to far more CDs than anything else the occasional 48 → 44.1 is not too great a loss.

The following assumes that there are not already other settings which conflict resp. overwrite it. This applies especially to the current user's potential ~/.asoundrc — which MPD as its own user ignores, therefore the following should go to /etc/asound.conf:

/etc/asound.conf

defaults.pcm.dmix.rate 44100 # Force 44.1 KHz
defaults.pcm.dmix.format S16_LE # Force 16 bits

/etc/mpd.conf

audio_output {
        type                    "alsa" # Use the ALSA output plugin.
	name			"your_custom_name" # Must be present and does not have to match the actual card name , e.g. what you have in /etc/asound.conf
        options                 "dev=dmixer"
        device                  "plug:dmix" # Both lines cause MPD to output to dmix
	format	        	"44100:16:2" # the actual format
	auto_resample		"no" # This bypasses ALSA's own algorithms, which generally are inferior. See below how to choose a different one.
}

ノート: MPD gives the mp3 format a special treatment at decoding: it is always put out as 24 bit. (The conversion as forced by the format line only comes after that.)

If one wants to leave the bit depth decision to ALSA resp. MPD, comment out resp. omit the dmix.format line and change the one for mpd with format to "44100:*:2".

ノート: Crossfading between files decoded at two different bit depths (say, one mp3 and one 16 bit flac) does not work unless conversion is active.

lirc で MPD をコントロール

There are already some clients designed for communications between lircd and MPD, however, as far as the practical use, they are not very useful since their functions are limited.

It is recommended to use mpc with irexec. mpc is a command line player which only sends the command to MPD and exits immediately, which is perfect for irexec, the command runner included in lirc. What irexec does is that it runs a specified command once received a remote control button.

First of all, please setup your remotes as referred to the Lirc article.

Edit your favored lirc startup configuration file, default location is ~/.lircrc.

Fill the file with the following pattern:

begin
     prog = irexec
     button = <button_name>
     config = <command_to_run>
     repeat = <0 or 1>
end

An example:

## irexec
begin
     prog = irexec
     button = play_pause
     config = mpc toggle
     repeat = 0
end

begin
     prog = irexec
     button = stop
     config = mpc stop
     repeat = 0
end
begin
     prog = irexec
     button = previous
     config = mpc prev
     repeat = 0
end
begin
     prog = irexec
     button = next
     config = mpc next
     repeat = 0
end
begin
     prog = irexec
     button = volup
     config = mpc volume +2
     repeat = 1
end
begin
     prog = irexec
     button = voldown
     config = mpc volume -2
     repeat = 1
end
begin
     prog = irexec
     button = pbc
     config = mpc random
     repeat = 0
end
begin
     prog = irexec
     button = pdvd
     config = mpc update
     repeat = 0
end
begin
     prog = irexec
     button = right
     config = mpc seek +00:00:05
     repeat = 0
end
begin
     prog = irexec
     button = left
     config = mpc seek -00:00:05
     repeat = 0
end
begin
     prog = irexec
     button = up
     config = mpc seek +1%
     repeat = 0
end
begin
     prog = irexec
     button = down
     config = mpc seek -1%
     repeat = 0
end

There are more functions for mpc, run man mpc for more info.

PulseAudio

ローカル (通常のユーザーを使用)

No special options are required; just add a pulse output as described in the comments of mpd's config file.

ローカル (特別な mpd ユーザーを使用)

When run as its own user as per the wiki instructions, mpd will be unable to send sound to another user's pulseaudio server. Rather than setting up pulseaudio as a system-wide daemon, a practice strongly discouraged by upstream, you can instead configure mpd to use pulseaudio's tcp module to send sound to localhost:

First, uncomment the tcp module in /etc/pulse/default.pa or $XDG_CONFIG_HOME/default.pa (typically ~/.config/pulse/default.pa) and set 127.0.0.1 as an allowed IP address; the home directory takes precedence:

### Network access (may be configured with paprefs, so leave this commented
### here if you plan to use paprefs)
#load-module module-esound-protocol-tcp
load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1
#load-module module-zeroconf-publish

Additional IP ranges in cidr notation may be added using ; as the separator. Once this is complete, restart pulseaudio:

$ pulseaudio --kill
$ pulseaudio --start -or- start-pulseaudio-x11/kde

Next, edit /etc/mpd.conf and add a new pulse output pointing to 127.0.0.1 as a "remote" server:

audio_output {
       type		"pulse"
       name		"Local Music Player Daemon"
       server		"127.0.0.1"
}

Once this is added, restart mpd.

Enable the output in mpd; you should now have a working local mpd, usable by all users whose pulseaudio servers allow sound from 127.0.0.1.

リモート

As with any PulseAudio-enabled program, mpd can send sound over the network. The complete PulseAudio system is not required on the server running mpd; libpulse is the only requirement to act as a source and is already a dependency of mpd.

In order to send audio from mpd to another computer follow the directions above, editing /etc/mpd.conf on the server running mpd using the IP address of the target computer and /etc/pulse/default.pa or $XDG_CONFIG_HOME/default.pa (typically ~/.config/pulse/default.pa) on the target computer using the IP address of the server.

Once this is done, the server's mpd source should show up on the target computer while playing or paused as a normal source able to be rerouted and controlled as usual; there will be no visible source on the target while mpd is stopped.

Cue ファイル

No additional steps are needed for cue support in mpd since 0.17. MPD has its own integrated parser which works with both external and embedded cuesheets. For example, the command mpc load albumx/x.cue loads the file music_directory/albumx/x.cue as playlist; or in the case of an CUESHEET tag, mpc load albumx/x.flac.

HTTP ストリーミング

Since version 0.15 there is a built-in HTTP streaming daemon/server that comes with MPD. To activate this server simply set it as output device in mpd.conf:

audio_output {    
	type		"httpd"    
	name		"My HTTP Stream"
	encoder		"vorbis"		# optional, vorbis or lame
	port		"8000"
#	quality		"5.0"			# do not define if bitrate is defined
	bitrate		"128"			# do not define if quality is defined
	format		"44100:16:1"
}

Then to listen to this stream simply open the URL of your mpd server (along with the specified port) in your favorite music player. Note: You may have to specify the file format of the stream using an appropriate file extension in the URL. For example, using Winamp 5.5, You would use http://192.168.1.2:8000/mpd.ogg rather than http://192.168.1.2:8000/.

To use mpd to connect to the stream from another computer.

mpc add http://192.168.1.2:8000