我拥有一台联想 Thinkpad L440。我会直接录制声卡输出，而不是从内部麦克风录制。我有 alsa 作为声音系统并运行 alsamixer 内容，它返回给我：
numid=23,iface=CARD,name='Dock Headphone Jack'
; type=BOOLEAN,access=r-------,values=1
: values=off
numid=19,iface=CARD,name='Dock Mic Jack'
; type=BOOLEAN,access=r-------,values=1
: values=off
numid=24,iface=CARD,name='Headphone Jack'
; type=BOOLEAN,access=r-------,values=1
: values=off
numid=21,iface=CARD,name='Internal Mic Phantom Jack'
; type=BOOLEAN,access=r-------,values=1
: values=on
numid=20,iface=CARD,name='Mic Jack'
; type=BOOLEAN,access=r-------,values=1
: values=off
numid=22,iface=CARD,name='Speaker Phantom Jack'
; type=BOOLEAN,access=r-------,values=1
: values=on
numid=18,iface=MIXER,name='Master Playback Switch'
; type=BOOLEAN,access=rw------,values=1
: values=on
numid=17,iface=MIXER,name='Master Playback Volume'
; type=INTEGER,access=rw---R--,values=1,min=0,max=87,step=0
: values=72
| dBscale-min=-65.25dB,step=0.75dB,mute=0
numid=4,iface=MIXER,name='Headphone Playback Switch'
; type=BOOLEAN,access=rw------,values=2
: values=off,off
numid=5,iface=MIXER,name='Headphone Playback Switch',index=1
; type=BOOLEAN,access=rw------,values=2
: values=off,off
numid=3,iface=MIXER,name='Headphone Playback Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=87,step=0
: values=71,71
| dBscale-min=-65.25dB,step=0.75dB,mute=0
numid=29,iface=MIXER,name='PCM Playback Volume'
; type=INTEGER,access=rw---RW-,values=2,min=0,max=255,step=0
: values=255,255
| dBscale-min=-51.00dB,step=0.20dB,mute=0
numid=15,iface=MIXER,name='Mic Boost Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=3,step=0
: values=1,1
| dBscale-min=0.00dB,step=10.00dB,mute=0
numid=10,iface=MIXER,name='Mic Playback Switch'
; type=BOOLEAN,access=rw------,values=2
: values=on,on
numid=9,iface=MIXER,name='Mic Playback Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=31,step=0
: values=12,12
| dBscale-min=-34.50dB,step=1.50dB,mute=0
numid=13,iface=MIXER,name='Capture Switch'
; type=BOOLEAN,access=rw------,values=2
: values=on,on
numid=12,iface=MIXER,name='Capture Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=63,step=0
: values=39,39
| dBscale-min=-17.25dB,step=0.75dB,mute=0
numid=6,iface=MIXER,name='Loopback Mixing'
; type=ENUMERATED,access=rw------,values=1,items=2
; Item #0 'Disabled'
; Item #1 'Enabled'
: values=1
numid=11,iface=MIXER,name='Auto-Mute Mode'
; type=ENUMERATED,access=rw------,values=1,items=2
; Item #0 'Disabled'
; Item #1 'Enabled'
: values=1
numid=26,iface=MIXER,name='Beep Playback Switch'
; type=BOOLEAN,access=rw------,values=2
: values=on,on
numid=25,iface=MIXER,name='Beep Playback Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=31,step=0
: values=11,11
| dBscale-min=-34.50dB,step=1.50dB,mute=0
numid=14,iface=MIXER,name='Dock Mic Boost Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=3,step=0
: values=0,0
| dBscale-min=0.00dB,step=12.00dB,mute=0
numid=8,iface=MIXER,name='Dock Mic Playback Switch'
; type=BOOLEAN,access=rw------,values=2
: values=off,off
numid=7,iface=MIXER,name='Dock Mic Playback Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=31,step=0
: values=0,0
| dBscale-min=-34.50dB,step=1.50dB,mute=0
numid=16,iface=MIXER,name='Internal Mic Boost Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=1,step=0
: values=0,0
| dBscale-min=0.00dB,step=12.00dB,mute=0
numid=2,iface=MIXER,name='Speaker Playback Switch'
; type=BOOLEAN,access=rw------,values=2
: values=on,on
numid=1,iface=MIXER,name='Speaker Playback Volume'
; type=INTEGER,access=rw---R--,values=2,min=0,max=87,step=0
: values=87,87
| dBscale-min=-65.25dB,step=0.75dB,mute=0
numid=28,iface=PCM,name='Capture Channel Map'
; type=INTEGER,access=r----R--,values=2,min=0,max=36,step=0
: values=0,0
| container
| chmap-fixed=FL,FR
numid=27,iface=PCM,name='Playback Channel Map'
; type=INTEGER,access=r----R--,values=4,min=0,max=36,step=0
: values=0,0,0,0
| container
| chmap-fixed=FL,FR
| chmap-fixed=FL,FR,RL,RR```
But I'm unable to do this with arecord. Is there a way to capture audio from soundcard with my hardware?