树莓派上Speaker-test可用但Snapclient无法使用Alsaeq的问题

环境信息 #

• 设备：树莓派4 B+
• 系统：Raspian，内核版本 Linux snapclient 6.1.21-v8+ #1642 SMP PREEMPT Mon Apr 3 17:24:16 BST 2023 aarch64 GNU/Linux
• 已安装组件：alsaequal、Snapclient（版本0.27.0）

正常测试情况 #

执行扬声器测试命令：

speaker-test -D equal

测试正常运行，且能通过 alsamixer -D equal 控制音频输出。

执行Snapclient设备列表命令：

snapclient -l

输出结果：

0: null
Discard all samples (playback) or generate zero samples (capture)

1: plugequal


2: equal


3: hw:CARD=sndrpihifiberry,DEV=0
snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
Direct hardware device without any conversions

4: plughw:CARD=sndrpihifiberry,DEV=0
snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
Hardware device with all software conversions

5: default:CARD=sndrpihifiberry
snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
Default Audio Device

6: sysdefault:CARD=sndrpihifiberry
snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
Default Audio Device

7: dmix:CARD=sndrpihifiberry,DEV=0
snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
Direct sample mixing device

错误情况 #

执行命令调用equal设备：

snapclient -s 2

出现错误输出：

2024-02-12 11-10-17.610 [Info] (Snapclient) Version 0.27.0, revision 54a3d862
2024-02-12 11-10-17.627 [Info] (Avahi) (Browser) NEW: service 'Snapcast' of type '_snapcast._tcp' in domain 'local'
2024-02-12 11-10-17.628 [Info] (Avahi) (Browser) CACHE_EXHAUSTED
2024-02-12 11-10-18.075 [Info] (Avahi) Service 'Snapcast' of type '_snapcast._tcp' in domain 'local':
2024-02-12 11-10-18.076 [Info] (Avahi)  snapserver.local:1704 (192.168.0.237)
2024-02-12 11-10-18.080 [Info] (Controller) Found server 192.168.0.237:1704
2024-02-12 11-10-18.080 [Info] (Connection) Resolving host IP for: 192.168.0.237
2024-02-12 11-10-18.081 [Info] (Connection) Connecting
2024-02-12 11-10-18.099 [Notice] (Connection) Connected to 192.168.0.237
2024-02-12 11-10-18.099 [Info] (Connection) My MAC: "d8:3a:dd:8e:4b:58", socket: 8
2024-02-12 11-10-18.301 [Info] (Controller) ServerSettings - buffer: 1000, latency: 0, volume: 48, muted: 0
2024-02-12 11-10-18.302 [Info] (Controller) Codec: flac, sampleformat: 44100:16:2
2024-02-12 11-10-18.302 [Info] (Player) Player name: alsa, device: equal, description: <none>, idx: 2, sharing mode: unspecified, parameters: <none>
2024-02-12 11-10-18.302 [Info] (Player) Mixer mode: software, parameters: <none>
2024-02-12 11-10-18.302 [Info] (Player) Sampleformat: 44100:16:2, stream: 44100:16:2
2024-02-12 11-10-18.302 [Info] (Alsa) Using default buffer_time: 80 ms, default fragments: 4
ALSA lib dlmisc.c:339:(snd_dlobj_cache_get0) Cannot open shared library libasound_module_pcm_equal.so (/lib/arm-linux-gnueabihf/alsa-lib/libasound_module_pcm_equal.so: cannot open shared object file: No such file or directory)
2024-02-12 11-10-18.303 [Error] (Alsa) Exception: Can't open equal, error: No such device or address, code: -6
2024-02-12 11-10-18.304 [Fatal] (Snapclient) Exception: Can't open equal, error: No such device or address
2024-02-12 11-10-18.304 [Notice] (Snapclient) Snapclient terminated.

问题分析与尝试解决 #

检查发现libasound_module_pcm_equal.so实际位于/lib/aarch64-linux-gnu/alsa-lib/，但Snapclient却试图在/lib/arm-linux-gnueabihf/alsa-lib/中查找该文件。

尝试创建软链接：

sudo ln -s /lib/aarch64-linux-gnu/alsa-lib/libasound_module_* /lib/arm-linux-gnueabihf/alsa-lib/

出现新错误：

ALSA lib dlmisc.c:339:(snd_dlobj_cache_get0) Cannot open shared library libasound_module_pcm_equal.so (/lib/arm-linux-gnueabihf/alsa-lib/libasound_module_pcm_equal.so: wrong ELF class: ELFCLASS64)

当前/etc/asound.conf配置：

ctl.equal {
    type equal;
}

pcm.plugequal {
    type equal;
    #slave.pcm "plughw:0,0";
    slave.pcm "plug:dmix"
}

pcm.equal {
    type plug;
    slave.pcm plugequal;
}

请问有什么办法可以解决这个问题？谢谢。

内容的提问来源于stack exchange，提问作者GSephElec