我已经使用 MPD v.0.19 和 Ubuntu 15.04 很长一段时间了，我想检查最新版本 0.20，因此下载了它并按照说明自己编译它。
不幸的是，这没有奏效，所以我想回到官方的 .deb MPD v0.19。
现在，重新安装 mpd 后，sudo apt-get purge mpd && sudo apt-get install mpd当我尝试播放歌曲时会弹出以下内容：
cat /var/log/mpd/mpd.log：
Nov 05 14:22 : client: [13] opened from local
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4260:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4260:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4260:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4739:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2267:(snd_pcm_open_noupdate) Unknown PCM default
Nov 05 14:22 : alsa_output: Failed to open "My ALSA Device" [alsa]: Failed to open ALSA device "default": No such file or directory
Nov 05 14:22 : output: Failed to open audio output
Nov 05 14:22 : client: [13] closed
mpd -v：
config_file: loading file /etc/mpd.conf
errno: Failed to open /etc/mpd.conf: Permission denied
ls -la /etc/mpd.conf：
-rw-r----- 1 mpd audio 14092 Jun 23 00:05 /etc/mpd.conf
mpd.conf：
# An example configuration file for MPD.
# Read the user manual for documentation: http://www.musicpd.org/doc/user/
# or /usr/share/doc/mpd/user-manual.html
# 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 "/var/lib/mpd/music"
#
# 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 "/var/lib/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 "/var/lib/mpd/tag_cache"
#
# These settings are the locations for the daemon log files for the daemon.
# These logs are great for troubleshooting, depending on your log_level
# settings.
#
# The special value "syslog" makes MPD use the local syslog daemon. This
# setting defaults to logging to syslog, otherwise logging is disabled.
#
log_file "/var/log/mpd/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.
#
pid_file "/run/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 "/var/lib/mpd/state"
#
# The location of the sticker database. This is a database which
# manages dynamic information attached to songs.
#
sticker_file "/var/lib/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 "mpd"
#
# 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 then the default, any.
# This setting can deny access to control of the daemon. Choose any if you want
# to have mpd listen on every address. Not effective if systemd socket
# activation is in use.
#
# For network
bind_to_address "localhost"
#
# And for Unix Socket
#bind_to_address "/run/mpd/socket"
#
# This setting is the TCP port that is desired for the daemon to get assigned
# to.
#
#port "6600"
#
# This setting controls the type of information which is logged. Available
# setting arguments are "default", "secure" or "verbose". The "verbose" setting
# argument is recommended for troubleshooting, though can quickly stretch
# available resources on limited hardware storage.
#
#log_level "default"
#
# If you have a problem with your MP3s ending abruptly it is recommended that
# you set this argument to "no" to attempt to fix the problem. If this solves
# the problem, it is highly recommended to fix the MP3 files with vbrfix
# (available as vbrfix in the debian archive), at which
# point gapless MP3 playback can be enabled.
#
#gapless_mp3_playback "yes"
#
# 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 mpd.conf man page.
#metadata_to_use "artist,album,title,track,name,genre,date,composer,performer,disc"
#
# 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.
#
#zeroconf_name "Music Player"
#
###############################################################################
# Permissions #################################################################
#
# If this setting is set, MPD will require password authorization. The password
# can 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 #######################################################################
#
#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"
# encoding "ogg" # 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)
# Please see README.Debian if you want mpd to play through the pulseaudio
# daemon started as part of your graphical desktop session!
#
#audio_output {
# type "pulse"
# name "My Pulse Output"
# server "remote_server" # optional
# sink "remote_server_sink" # 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 an openal output.
#
#audio_output {
# type "openal"
# name "My OpenAL output"
# device "Digital Audio (S/PDIF) (High Definition Audio Device)" # 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
#}
#
# If MPD has been compiled with libsamplerate support, this setting specifies
# the sample rate converter to use. Possible values can be found in the
# mpd.conf man page or the libsamplerate documentation. By default, this is
# setting is disabled.
#
#samplerate_converter "Fastest Sinc Interpolator"
#
###############################################################################
# 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 <http://www.replaygain.org> 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"
#
# This setting controls the encoding that ID3v1 tags should be converted from.
#
id3v1_encoding "UTF-8"
#
###############################################################################
# SIDPlay decoder #############################################################
#
# songlength_database:
# Location of your songlengths file, as distributed with the HVSC.
# The sidplay plugin checks this for matching MD5 fingerprints.
# See http://www.c64.org/HVSC/DOCUMENTS/Songlengths.faq
#
# default_songlength:
# This is the default playing time in seconds for songs not in the
# songlength database, or in case you're not using a database.
# A value of 0 means play indefinitely.
#
# filter:
# Turns the SID filter emulation on or off.
#
#decoder {
# plugin "sidplay"
# songlength_database "/media/C64Music/DOCUMENTS/Songlengths.txt"
# default_songlength "120"
# filter "true"
#}
#
###############################################################################
我的系统声音运行正常，只是 MPD/MPC 无法播放声音。
任何帮助都将不胜感激！
答案1
愚蠢的我sudo adduser mpd在尝试从 git 中获取自定义版本时失败了。这对实际的 MPD 来说是个问题。
解决方案：
sudo deluser mpd
如果由于 MPD 仍在运行而失败：
ps aux | grep mpd
和
sudo kill -9 id-of-running-process
享受！