mdp randomly unable to play music – macOS M1 ; ncmpcpp/MPDroid clients

[sylvainsab]

Bug report

Describe the bug

Everything on the client side seems smooth, until sending the command to start playing a file : nothing happens.
The bug has been happening on and off periodically, with seemingly no particular reason and software mostly up to date (both Apple store and brew updates).

I use ncmpcpp as a client on the same laptop (MacBook Air with the M1 chip) as well as on a remote client laptop.
This software would let me know something's wrong because it displays "Volume: n/a" on the top-right corner instead of the usual "Volume: 100%" or other percentage.
On the MPDroid client (Android phone client) everything seems as usual but when loading a track it won't start playing either.

It is not just a problem of muted volume because I can see that the progress bar that is usually displayed when playing a song stays absent.

Note :
· I included the config file but it's only very slightly modified.
· The error (socket already in use) is most likely because mpd is already running as a dæmon
· I also use the amphetamine software so I can keep my laptop in wakeful mode and start playing music remotely whenever.

Expected Behavior

· Open either client (ncmpcpp or MPDroid) from either place (locally on the mac, remotely on the other laptop, remotely from the phone)
· Display the library and choose some track(s) to play
· The track(s) will play, sound be heard and the usual progress bar display the advance in the current song

Actual Behavior

· Open either client (ncmpcpp or MPDroid) from either place (locally on the mac, remotely on the other laptop, remotely from the phone)
· Display the library and choose some track(s) to play
· No track will play, no sound and no progress bar – the interface stays dead although the playlist gets populated

Version

Music Player Daemon 0.23.13 (0.23.13)

Configuration

# An example configuration file for MPD.
# Read the user manual for documentation: http://www.musicpd.org/doc/user/


# Files and directories #######################################################
#
# This setting controls the top directory which MPD will search to discover the
# available audio files and add them to the daemon's online database. This
# setting defaults to the XDG directory, otherwise the music directory will be
# be disabled and audio files will only be accepted over ipc socket (using
# file:// protocol) or streaming files over an accepted protocol.
#
music_directory		"~/Music/Musithèque/"
#
# This setting sets the MPD internal playlist directory. The purpose of this
# directory is storage for playlists created by MPD. The server will use
# playlist files not created by the server but only if they are in the MPD
# format. This setting defaults to playlist saving being disabled.
#
playlist_directory		"~/.mpd/playlists"
#
# This setting sets the location of the MPD database. This file is used to
# load the database at server start up and store the database while the
# server is not up. This setting defaults to disabled which will allow
# MPD to accept files over ipc socket (using file:// protocol) or streaming
# files over an accepted protocol.
#
db_file			"~/.mpd/database"

# These settings are the locations for the daemon log files for the daemon.
#
# The special value "syslog" makes MPD use the local syslog daemon. This
# setting defaults to logging to syslog.
#
# If you use systemd, do not configure a log_file.  With systemd, MPD
# defaults to the systemd journal, which is fine.
#
#log_file			"~/.mpd/log"

# This setting sets the location of the file which stores the process ID
# for use of mpd --kill and some init scripts. This setting is disabled by
# default and the pid file will not be stored.
#
# If you use systemd, do not configure a pid_file.
#
#pid_file			"~/.mpd/pid"

# This setting sets the location of the file which contains information about
# most variables to get MPD back into the same general shape it was in before
# it was brought down. This setting is disabled by default and the server
# state will be reset on server start up.
#
#state_file			"~/.mpd/state"
#
# The location of the sticker database.  This is a database which
# manages dynamic information attached to songs.
#
#sticker_file			"~/.mpd/sticker.sql"
#
###############################################################################


# General music daemon options ################################################
#
# This setting specifies the user that MPD will run as. MPD should never run as
# root and you may use this setting to make MPD change its user ID after
# initialization. This setting is disabled by default and MPD is run as the
# current user.
#
#user				"nobody"
#
# This setting specifies the group that MPD will run as. If not specified
# primary group of user specified with "user" setting will be used (if set).
# This is useful if MPD needs to be a member of group such as "audio" to
# have permission to use sound card.
#
#group				"nogroup"
#
# This setting sets the address for the daemon to listen on. Careful attention
# should be paid if this is assigned to anything other than the default, any.
# This setting can deny access to control of the daemon. Not effective if
# systemd socket activiation is in use.
#
# For network
#bind_to_address		"any"
#
# And for Unix Socket
#bind_to_address		"~/.mpd/socket"
#
# This setting is the TCP port that is desired for the daemon to get assigned
# to.
#
#port				"6600"
#
# Suppress all messages below the given threshold.  Use "verbose" for
# troubleshooting. Available setting arguments are "notice", "info", "verbose",
# "warning" and "error".
#
#log_level			"notice"
#
# Setting "restore_paused" to "yes" puts MPD into pause mode instead
# of starting playback after startup.
#
#restore_paused "no"
#
# This setting enables MPD to create playlists in a format usable by other
# music players.
#
#save_absolute_paths_in_playlists	"no"
#
# This setting defines a list of tag types that will be extracted during the
# audio file discovery process. The complete list of possible values can be
# found in the user manual.
#metadata_to_use	"artist,album,title,track,name,genre,date,composer,performer,disc"
#
# This example just enables the "comment" tag without disabling all
# the other supported tags:
#metadata_to_use "+comment"
metadata_to_use "+albumartist"
#
# This setting enables automatic update of MPD's database when files in
# music_directory are changed.
#
#auto_update	"yes"
#
# Limit the depth of the directories being watched, 0 means only watch
# the music directory itself.  There is no limit by default.
#
#auto_update_depth "3"
#
###############################################################################


# Symbolic link behavior ######################################################
#
# If this setting is set to "yes", MPD will discover audio files by following
# symbolic links outside of the configured music_directory.
#
#follow_outside_symlinks	"yes"
#
# If this setting is set to "yes", MPD will discover audio files by following
# symbolic links inside of the configured music_directory.
#
#follow_inside_symlinks		"yes"
#
###############################################################################


# Zeroconf / Avahi Service Discovery ##########################################
#
# If this setting is set to "yes", service information will be published with
# Zeroconf / Avahi.
#
#zeroconf_enabled		"yes"
#
# The argument to this setting will be the Zeroconf / Avahi unique name for
# this MPD server on the network. %h will be replaced with the hostname.
#
#zeroconf_name			"Music Player @ %h"
#
###############################################################################


# Permissions #################################################################
#
# If this setting is set, MPD will require password authorization. The password
# setting can be specified multiple times for different password profiles.
#
#password                        "password@read,add,control,admin"
#
# This setting specifies the permissions a user has who has not yet logged in.
#
#default_permissions             "read,add,control,admin"
#
###############################################################################


# Database #######################################################################
#
# An example of a database section instead of the old 'db_file' setting.
# It enables mounting other storages into the music directory.
#
#database {
#       plugin "simple"
#       path "~/.local/share/mpd/db
#       cache_directory "~/.local/share/mpd/cache"
#}
#
# An example of database config for a sattelite setup
#
#music_directory "nfs://fileserver.local/srv/mp3"
#database {
#       plugin "proxy"
#       host "other.mpd.host"
#       port "6600"
#}

# Input #######################################################################
#
input {
        plugin "curl"
#       proxy "proxy.isp.com:8080"
#       proxy_user "user"
#       proxy_password "password"
}

#
###############################################################################

# Audio Output ################################################################
#
# MPD supports various audio output types, as well as playing through multiple
# audio outputs at the same time, through multiple audio_output settings
# blocks. Setting this block is optional, though the server will only attempt
# autodetection for one sound card.
#
# An example of an ALSA output:
#
#audio_output {
#	type		"alsa"
#	name		"My ALSA Device"
##	device		"hw:0,0"	# optional
##	mixer_type      "hardware"	# optional
##	mixer_device	"default"	# optional
##	mixer_control	"PCM"		# optional
##	mixer_index	"0"		# optional
#}
#
# An example of an OSS output:
#
#audio_output {
#	type		"oss"
#	name		"My OSS Device"
##	device		"/dev/dsp"	# optional
##	mixer_type      "hardware"	# optional
##	mixer_device	"/dev/mixer"	# optional
##	mixer_control	"PCM"		# optional
#}
#
# An example of a shout output (for streaming to Icecast):
#
#audio_output {
#	type		"shout"
#	encoder		"vorbis"		# optional
#	name		"My Shout Stream"
#	host		"localhost"
#	port		"8000"
#	mount		"/mpd.ogg"
#	password	"hackme"
#	quality		"5.0"
#	bitrate		"128"
#	format		"44100:16:1"
##	protocol	"icecast2"		# optional
##	user		"source"		# optional
##	description	"My Stream Description"	# optional
##	url		"http://example.com"	# optional
##	genre		"jazz"			# optional
##	public		"no"			# optional
##	timeout		"2"			# optional
##	mixer_type      "software"		# optional
#}
#
# An example of a recorder output:
#
#audio_output {
#	type		"recorder"
#	name		"My recorder"
#	encoder		"vorbis"		# optional, vorbis or lame
#	path		"/var/lib/mpd/recorder/mpd.ogg"
##	quality		"5.0"			# do not define if bitrate is defined
#	bitrate		"128"			# do not define if quality is defined
#	format		"44100:16:1"
#}
#
# An example of a httpd output (built-in HTTP streaming server):
#
#audio_output {
#	type		"httpd"
#	name		"My HTTP Stream"
#	encoder		"vorbis"		# optional, vorbis or lame
#	port		"8000"
#	bind_to_address	"0.0.0.0"		# optional, IPv4 or IPv6
##	quality		"5.0"			# do not define if bitrate is defined
#	bitrate		"128"			# do not define if quality is defined
#	format		"44100:16:1"
#	max_clients	"0"			# optional 0=no limit
#}
#
# An example of a pulseaudio output (streaming to a remote pulseaudio server)
#
#audio_output {
#	type		"pulse"
#	name		"My Pulse Output"
##	server		"remote_server"		# optional
##	sink		"remote_server_sink"	# optional
##	media_role	"media_role"		#optional
#}
#
# An example of a winmm output (Windows multimedia API).
#
#audio_output {
#	type		"winmm"
#	name		"My WinMM output"
##	device		"Digital Audio (S/PDIF) (High Definition Audio Device)" # optional
#		or
##	device		"0"		# optional
##	mixer_type	"hardware"	# optional
#}
#
# An example of a wasapi output (Windows multimedia API).
#
#audio_output {
#	type		"wasapi"
#	name		"My WASAPI output"
##	device		"Digital Audio (S/PDIF) (High Definition Audio Device)" # optional
#		or
##	device		"0"		# optional
## Exclusive mode blocks all other audio source, and get best audio quality without resampling.
##	exclusive	"no"		# optional
## Enumerate all devices in log.
##	enumerate	"no"		# optional
#}
#
# An example of an openal output.
#
#audio_output {
#	type		"openal"
#	name		"My OpenAL output"
##	device		"Digital Audio (S/PDIF) (High Definition Audio Device)" # optional
#}
#
# An example of an sndio output.
#
#audio_output {
#	type		"sndio"
#	name		"sndio output"
#	mixer_type	"hardware"
#}
#
# An example of an OS X output:
#
#audio_output {
#	type		"osx"
#	name		"My OS X Device"
##	device		"Built-in Output"	# optional
##	channel_map      "-1,-1,0,1"	# optional
#}
#
## Example "pipe" output:
#
#audio_output {
#	type		"pipe"
#	name		"my pipe"
#	command		"aplay -f cd 2>/dev/null"
## Or if you're want to use AudioCompress
#	command		"AudioCompress -m | aplay -f cd 2>/dev/null"
## Or to send raw PCM stream through PCM:
#	command		"nc example.org 8765"
#	format		"44100:16:2"
#}
#
## An example of a null output (for no audio output):
#
#audio_output {
#	type		"null"
#	name		"My Null Output"
#	mixer_type      "none"			# optional
#}
#
###############################################################################


# Normalization automatic volume adjustments ##################################
#
# This setting specifies the type of ReplayGain to use. This setting can have
# the argument "off", "album", "track" or "auto". "auto" is a special mode that
# chooses between "track" and "album" depending on the current state of
# random playback. If random playback is enabled then "track" mode is used.
# See <https://wiki.hydrogenaud.io/index.php?title=Replaygain> for
# more details about ReplayGain.
# This setting is off by default.
#
#replaygain			"album"
#
# This setting sets the pre-amp used for files that have ReplayGain tags. By
# default this setting is disabled.
#
#replaygain_preamp		"0"
#
# This setting sets the pre-amp used for files that do NOT have ReplayGain tags.
# By default this setting is disabled.
#
#replaygain_missing_preamp	"0"
#
# This setting enables or disables ReplayGain limiting.
# MPD calculates actual amplification based on the ReplayGain tags
# and replaygain_preamp / replaygain_missing_preamp setting.
# If replaygain_limit is enabled MPD will never amplify audio signal
# above its original level. If replaygain_limit is disabled such amplification
# might occur. By default this setting is enabled.
#
#replaygain_limit		"yes"
#
# This setting enables on-the-fly normalization volume adjustment. This will
# result in the volume of all playing audio to be adjusted so the output has
# equal "loudness". This setting is disabled by default.
#
#volume_normalization		"no"
#
###############################################################################

# Character Encoding ##########################################################
#
# If file or directory names do not display correctly for your locale then you
# may need to modify this setting.
#
#filesystem_charset		"UTF-8"
#
###############################################################################

Log

sylvain@sylvainmac ~ % mpd --stderr -v --no-daemon
config_file: loading file /Users/sylvain/.mpd/mpd.conf
exception: Failed to bind to '[::]:6600'; Failed to bind socket: Address already in use

[MaxKellermann]

Your log shows that you failed to start MPD, and thus MPD isn't running.

[sylvainsab]

seems I needed to autorun mpd at boot using :

% brew services stop mpd
% brew services start mpd