音频设备列表中0 1 7三个设备分别代表什么？

luffycheung

1. / # cat /proc/asound/cards
   
2. 0 [rockchiprk3308v]: rockchip_rk3308 - rockchip,rk3308-vad
   
3.                       rockchip,rk3308-vad
   
4. 1 [rockchiprk3308p]: rockchip_rk3308 - rockchip,rk3308-pcm
   
5.                       rockchip,rk3308-pcm
   
6. 7 [Loopback       ]: Loopback - Loopback
   
7.                       Loopback 1
   
8. / # arecord -l
   
9. **** List of CAPTURE Hardware Devices ****
   
10. card 0: rockchiprk3308v [rockchip,rk3308-vad], device 0: dailink-multicodecs multicodec-0 []
    
11.   Subdevices: 1/1
    
12.   Subdevice #0: subdevice #0
    
13. card 1: rockchiprk3308p [rockchip,rk3308-pcm], device 0: dailink-multicodecs dummy_codec-0 []
    
14.   Subdevices: 1/1
    
15.   Subdevice #0: subdevice #0
    
16. card 7: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
    
17.   Subdevices: 8/8
    
18.   Subdevice #0: subdevice #0
    
19.   Subdevice #1: subdevice #1
    
20.   Subdevice #2: subdevice #2
    
21.   Subdevice #3: subdevice #3
    
22.   Subdevice #4: subdevice #4
    
23.   Subdevice #5: subdevice #5
    
24.   Subdevice #6: subdevice #6
    
25.   Subdevice #7: subdevice #7
    
26. card 7: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
    
27.   Subdevices: 7/8
    
28.   Subdevice #0: subdevice #0
    
29.   Subdevice #1: subdevice #1
    
30.   Subdevice #2: subdevice #2
    
31.   Subdevice #3: subdevice #3
    
32.   Subdevice #4: subdevice #4
    
33.   Subdevice #5: subdevice #5
    
34.   Subdevice #6: subdevice #6
    
35.   Subdevice #7: subdevice #7

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luffycheung

声卡0 用于lineout 和耳机输出，同时也通过该声卡录制8通道的模拟Mic 输入，这样理解对吗？？？？
arecord 录音时指定的hw:0,0 是通过麦克风阵列选择不同通道进行录音的吗？？？？
声卡1 和7 loopback又有什么作用呢？？？

firefly_zhongw

根据rk3308-firefly.dtsi和rk3308-roc-cc-dmic-pdm_emmc.dts的描述
声卡0 是数字麦克阵列
声卡1  是蓝牙
声卡7  是回采