我尝试使用我的ladspa启用示例hpf插件~/.asoundrc，但无法启动。我如下创建了~/.asoundrc：
pcm.hpfilter {
type ladspa
slave.pcm "default"
path "/usr/lib/ladspa"
plugins [{
label hpf
input {
controls [ 250 ]
}
}]
}
并且插件在aplay -L上可见：
default
Playback/recording through the PulseAudio sound server
null
Discard all samples (playback) or generate zero samples (capture)
hpfilter
High pass filter
hdmi:CARD=HDMI,DEV=0
HDA Intel HDMI, HDMI 0
HDMI Audio Output
hdmi:CARD=HDMI,DEV=1
HDA Intel HDMI, HDMI 1
HDMI Audio Output
hdmi:CARD=HDMI,DEV=2
HDA Intel HDMI, HDMI 2
HDMI Audio Output
dmix:CARD=HDMI,DEV=3
HDA Intel HDMI, HDMI 0
Direct sample mixing device
dmix:CARD=HDMI,DEV=7
HDA Intel HDMI, HDMI 1
Direct sample mixing device
dmix:CARD=HDMI,DEV=8
HDA Intel HDMI, HDMI 2
Direct sample mixing device
dsnoop:CARD=HDMI,DEV=3
HDA Intel HDMI, HDMI 0
Direct sample snooping device
dsnoop:CARD=HDMI,DEV=7
HDA Intel HDMI, HDMI 1
Direct sample snooping device
dsnoop:CARD=HDMI,DEV=8
HDA Intel HDMI, HDMI 2
Direct sample snooping device
hw:CARD=HDMI,DEV=3
HDA Intel HDMI, HDMI 0
Direct hardware device without any conversions
hw:CARD=HDMI,DEV=7
HDA Intel HDMI, HDMI 1
Direct hardware device without any conversions
hw:CARD=HDMI,DEV=8
HDA Intel HDMI, HDMI 2
Direct hardware device without any conversions
plughw:CARD=HDMI,DEV=3
HDA Intel HDMI, HDMI 0
Hardware device with all software conversions
plughw:CARD=HDMI,DEV=7
HDA Intel HDMI, HDMI 1
Hardware device with all software conversions
plughw:CARD=HDMI,DEV=8
HDA Intel HDMI, HDMI 2
Hardware device with all software conversions
sysdefault:CARD=PCH
HDA Intel PCH, ALC892 Analog
Default Audio Device
front:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
Front speakers
surround21:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
2.1 Surround output to Front and Subwoofer speakers
surround40:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Digital
IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
Direct sample mixing device
dmix:CARD=PCH,DEV=1
HDA Intel PCH, ALC892 Digital
Direct sample mixing device
dsnoop:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
Direct sample snooping device
dsnoop:CARD=PCH,DEV=1
HDA Intel PCH, ALC892 Digital
Direct sample snooping device
hw:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
Direct hardware device without any conversions
hw:CARD=PCH,DEV=1
HDA Intel PCH, ALC892 Digital
Direct hardware device without any conversions
plughw:CARD=PCH,DEV=0
HDA Intel PCH, ALC892 Analog
Hardware device with all software conversions
plughw:CARD=PCH,DEV=1
HDA Intel PCH, ALC892 Digital
Hardware device with all software conversions
但我无法通过它播放任何内容：
$ aplay -D plug:hpfilter /usr/share/sounds/alsa/Noise.wav
Playing WAVE '/usr/share/sounds/alsa/Noise.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono
ALSA lib pcm_params.c:2162:(snd1_pcm_hw_refine_slave) Slave PCM not usable
aplay: set_params:1270: Broken configuration for this PCM: no configurations available
思想型aplay -D default /usr/share/sounds/alsa/Noise.wav完美地工作。我已禁用pulseaudio，并尝试了aplay -D front:1,0 /usr/share/sounds/alsa/Noise.wav和其他一些工具，但一切正常，但是在ladspa插件的.asoundrc中放置了这样的pcm之后，我只收到Broken configuration for this PCM: no configurations available
我在这里想念谁？