android 音频系统用到的命令记录

ls /dev/snd 查看音频设备

 

手动加载了驱动程序：

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

 

查看声卡： cat /proc/asound/cards

配置文件: /etc/asond.conf

 

切换底层入口是alsa_default.cpp，需要在asound.conf定义好local CODEC和USB Audio的plug；还需要修改alsa_default.cpp，最主要Android要知道USB Audio插上时打开USB Audio的plug，USB Audio拔下时打开local CODEC的plug

 

设置命令

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

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

查看声音是否正确设置：

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
        oneshot