OpenWrt 21.02.3中MPD无法加载FFmpeg解码器的问题求助

问题概述 #

在OpenWrt 21.02.3系统中部署MPD，已编译安装mpd-full、libffmpeg-full及ffmpeg-full包，但MPD无法加载FFmpeg解码器。手动在/etc/mpd.conf中添加解码器配置后仍无效。

当前配置与环境信息 #

mpd.conf配置

log_file "syslog"

bind_to_address "127.0.0.1"
bind_to_address "192.168.1.16"

input {
    plugin          "curl"
}

audio_output {
    type            "alsa"
    name            "sun4icodec"
    device          "plug:dmix"
    mixer_control   "Power Amplifier"
}

decoder {
     plugin  "ffmpeg"
     enabled  "yes"
}

mpd --version输出

Music Player Daemon 0.21.26 (v21.02.3)
Copyright 2003-2007 Warren Dukes <warren.dukes@gmail.com>
Copyright 2008-2018 Max Kellermann <max.kellermann@gmail.com>
This is free software; see the source for copying conditions.  There is NO
warranty; not even MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Database plugins:
 simple proxy upnp

Storage plugins:
 local curl


Decoders plugins:
 [mad] mp3 mp2
 [vorbis] ogg oga
 [oggflac] ogg oga
 [flac] flac
 [opus] opus ogg oga
 [faad] aac
 [pcm]

Filters:


Tag plugins:
 id3tag

Output plugins:
 shout null fifo pipe alsa pulse httpd recorder

Encoder plugins:
 null opus wave flac

Input plugins:
 file alsa curl mms

Playlist plugins:
 extm3u m3u pls xspf asx rss soundcloud flac cue embcue

Protocols:
 file:// alsa:// http:// https:// mms:// mmsh:// mmst:// mmsu://

Other features:
 epoll iconv inotify ipv6 tcp un

理想解码器列表（预期）

Decoders plugins:
 [dsdiff] dff
 [dsf] dsf
 [ffmpeg] 16sv 3g2 3gp 4xm 8svx aa3 aac ac3 adx afc aif aifc aiff al alaw amr anim apc ape asf atrac au aud avi avm2 avs bap bfi c93 cak cin cmv cpk daud dct divx dts dv dvd dxa eac3 film flac flc fli fll flx flv g726 gsm gxf iss m1v m2v m2t m2ts m4a m4b m4v mad mj2 mjpeg mjpg mka mkv mlp mm mmf mov mp+ mp1 mp2 mp3 mp4 mpc mpeg mpg mpga mpp mpu mve mvi mxf nc nsv nut nuv oga ogm ogv ogx oma ogg omg opus psp pva qcp qt r3d ra ram rl2 rm rmvb roq rpl rvc shn smk snd sol son spx str swf tak tgi tgq tgv thp ts tsp tta xa xvid uv uv2 vb vid vob voc vp6 vmd wav webm wma wmv wsaud wsvga wv wve
 [pcm]

Filters:

系统日志与FFmpeg信息

MPD守护进程日志：

Mon Jul 25 09:40:30 2022 daemon.err mpd[1969]: exception: Error in /etc/mpd.conf line 17; Unknown tokens after '{'
Mon Jul 25 09:44:23 2022 daemon.debug mpd: vorbis: Xiph.Org libVorbis 1.3.7
Mon Jul 25 09:44:23 2022 daemon.debug mpd: opus: libopus 1.3.1-fixed
Mon Jul 25 09:44:23 2022 daemon.debug mpd: curl: version 7.82.0
Mon Jul 25 09:44:23 2022 daemon.debug mpd: curl: with mbedTLS/2.16.12

FFmpeg版本输出：

ffmpeg version 4.3.3 Copyright (c) 2000-2021 the FFmpeg developers
  built with gcc 8.4.0 (OpenWrt GCC 8.4.0 r16554-1d4dea6d4f)
  configuration: --enable-cross-compile --cross-prefix=arm-openwrt-linux-muslgnueabi- --arch=arm --cpu=cortex-a7 --target-os=linux --prefix=/usr --pkg-config=pkg-config --enable-shared --enable-static --enable-pthreads --enable-zlib --disable-doc --disable-debug --disable-lzma --disable-vaapi --disable-vdpau --disable-outdevs --disable-runtime-cpudetect --enable-lto --enable-vfp --enable-neon --enable-vfp --disable-x86asm --enable-hardcoded-tables --enable-gpl --enable-version3 --enable-nonfree --disable-swscale --disable-everything --enable-encoder=ac3 --enable-encoder=jpegls --enable-encoder=mpeg1video --enable-encoder=mpeg2video --enable-encoder=pcm_s16be --enable-encoder=pcm_s16le --enable-encoder=png --enable-encoder=vorbis --enable-encoder=zlib --enable-decoder=aac --enable-decoder=ac3 --enable-decoder=alac --enable-decoder=amrnb --enable-decoder=amrwb --enable-decoder=ape --enable-decoder=flac --enable-decoder=jpegls --enable-decoder=mp2 --enable-decoder=mp3 --enable-decoder=mpeg1video --enable-decoder=mpeg2video --enable-decoder=mpeg4 --enable-decoder=mpegvideo --enable-decoder=mpc7 --enable-decoder=mpc8 --enable-decoder=pcm_s16be --enable-decoder=pcm_s16le --enable-decoder=png --enable-decoder=vorbis --enable-decoder=wavpack --enable-decoder=wmav1 --enable-decoder=wmav2 --enable-decoder=zlib --enable-muxer=ac3 --enable-muxer=mp3 --enable-muxer=mp4 --enable-muxer=mpeg1video --enable-muxer=mpeg2video --enable-muxer=mpegts --enable-muxer=ogg --enable-muxer=rtp --enable-demuxer=aac --enable-demuxer=ac3 --enable-demuxer=amr --enable-demuxer=ape --enable-demuxer=avi --enable-demuxer=flac --enable-demuxer=matroska --enable-demuxer=mov --enable-demuxer=mp3 --enable-demuxer=mpegps --enable-demuxer=mpegts --enable-demuxer=mpegvideo --enable-demuxer=mpc --enable-demuxer=mpc8 --enable-demuxer=ogg --enable-demuxer=rm --enable-demuxer=rtsp --enable-demuxer=rtp --enable-demuxer=sdp --enable-demuxer=wav --enable-demuxer=wv --enable-parser=aac --enable-parser=flac --enable-parser=ac3 --enable-parser=mpegaudio --enable-parser=mpeg4video --enable-parser=mpegvideo --enable-protocol=file --enable-protocol=http --enable-protocol=icecast --enable-protocol=pipe --enable-protocol=rtp --enable-protocol=tcp --enable-protocol=udp --enable-decoder=adpcm_ima_wav --enable-decoder=adpcm_ima_qt --enable-decoder=adpcm_ms --enable-libfdk-aac --enable-encoder=libfdk_aac --enable-libmp3lame --enable-encoder=libmp3lame --enable-libopus --enable-decoder=libopus --enable-encoder=libopus --enable-libshine --enable-encoder=libshine --disable-postproc
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libswresample   3.  7.100 /  3.  7.100
Hyper fast Audio and Video encoder
usage: ffmpeg [options] [[infile options] -i infile]... {[outfile options] outfile}...

排查与解决步骤 #

1. 修复mpd.conf语法错误 #

日志明确提示配置文件第17行存在语法问题，需做以下修正：

• 确保所有引号为英文双引号，避免使用中文引号“”
• 规范decoder块的缩进与格式，修改为：

decoder {
    plugin "ffmpeg"
    enabled "yes"
}

修改后重启MPD服务：

/etc/init.d/mpd restart

再次查看系统日志，确认配置错误已消除。

2. 验证MPD与FFmpeg库的链接 #

使用ldd命令检查MPD是否已关联FFmpeg库：

ldd /usr/bin/mpd | grep ffmpeg

若无输出，说明当前mpd-full包编译时未启用FFmpeg支持，需重新编译：

• 进入OpenWrt编译环境，执行make menuconfig
• 导航到Multimedia > Sound > mpd，勾选ffmpeg解码器选项
• 确认依赖的libffmpeg-full已选中
• 重新编译mpd-full包，完成后刷入固件或直接安装编译好的ipk文件

3. 确认FFmpeg库完整性 #

检查libffmpeg-full包是否完整：

opkg verify libffmpeg-full

若包存在损坏或缺失，重新安装：

opkg remove libffmpeg-full && opkg install libffmpeg-full

4. 验证修复效果 #

重启MPD后，执行以下命令检查解码器列表：

mpd --version

若输出的解码器列表中出现[ffmpeg]及对应格式，说明问题已解决。

内容的提问来源于stack exchange，提问作者dmSherazi