android 音頻系統用到的命令記錄

ls /dev/snd 查看音頻設備

 

手動加載了驅動程序：

insmod /system/lib/modules/snd-hwdep.ko
insmod /system/lib/modules/snd-hwdep.ko
 insmod /system/lib/modules/snd-rawmidi.ko
insmod /system/lib/modules/snd-rawmidi.ko
insmod /system/lib/modules/snd-usbmidi-lib.ko
insmod /system/lib/modules/snd-usbmidi-lib.ko

insmod /system/lib/modules/snd-usb-audio.ko
insmod /system/lib/modules/snd-usb-audio.ko

 

ls /dev/snd
controlC0
controlC1
pcmC0D0c
pcmC0D0p
pcmC1D0c
pcmC1D0p
timer

 

查看聲卡： cat /proc/asound/cards

配置文件: /etc/asond.conf

 

切換底層入口是alsa_default.cpp，需要在asound.conf定義好local CODEC和USB Audio的plug；還需要修改alsa_default.cpp，最主要Android要知道USB Audio插上時打開USB Audio的plug，USB Audio拔下時打開local CODEC的plug

 

設置命令

alsa_amixer cset numid=16,iface=MIXER,name='Speaker Playback Volume' 35

alsa_amixer cset numid=2,iface=MIXER,name='MIC1 Boost' 6

查看聲音是否正確設置：

alsa_amixer cget numid=2,iface=MIXER,name='MIC1 Boost'

alsa_amixer cget numid=16,iface=MIXER,name='Speaker Playback Volume'

 

service asound_conf /system/bin/alsa_ctl restore
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