前几天在嵌入式linux上用到alsa command,网上查的资料多不给力,只有动手一点点查,终于可以用了,将这个使用方法告诉大家,以免大家少走弯路。
0.先查看系统支持哪几个alsa cmd:
ll /system/bin/asla*
经查,我的android4.4.2+linux3.10 的系统支持如下 alsa cmd
-rwxr-xr-x root shell 68242 2014-10-08 05:18 alsa_amixer
-rwxr-xr-x root shell 67639 2014-10-08 05:18 alsa_aplay-rwxr-xr-x root shell 130323 2014-10-08 05:18 alsa_ctl不同的系统可以稍有不同,比如有的系统就叫aplay\amixer .....
1.如何使用alsa_aplay:
alsa_aplay -h //看一下目前支持哪些用法
-h, --help help
--version print current version-l, --list-devices list all soundcards and digital audio devices-L, --list-pcms list device names-D, --device=NAME select PCM by name-q, --quiet quiet mode-t, --file-type TYPE file type (voc, wav, raw or au)-c, --channels=# channels-f, --format=FORMAT sample format (case insensitive)-r, --rate=# sample rate-d, --duration=# interrupt after # seconds-M, --mmap mmap stream-N, --nonblock nonblocking mode-F, --period-time=# distance between interrupts is # microseconds-B, --buffer-time=# buffer duration is # microseconds --period-size=# distance between interrupts is # frames --buffer-size=# buffer duration is # frames-A, --avail-min=# min available space for wakeup is # microseconds-R, --start-delay=# delay for automatic PCM start is # microseconds (relative to buffer size if <= 0)-T, --stop-delay=# delay for automatic PCM stop is # microseconds from xrun-v, --verbose show PCM structure and setup (accumulative)-V, --vumeter=TYPE enable VU meter (TYPE: mono or stereo)-I, --separate-channels one file for each channel --disable-resample disable automatic rate resample --disable-channels disable automatic channel conversions --disable-format disable automatic format conversions --disable-softvol disable software volume control (softvol) --test-position test ring buffer position --test-coef=# test coeficient for ring buffer position (default 8) expression for validation is: coef * (buffer_size / 2) --test-nowait do not wait for ring buffer - eats whole CPU --max-file-time=# start another output file when the old file has recorded for this many seconds --process-id-file write the process ID here --use-strftime apply the strftime facility to the output file name会有详细的help说明,这个就不说了,可以自己试。
alsa_aplay -l //列出系统有几个声卡(card 0/1/2....), 及每个卡的一个设备(device 0/1/2....)比如我的系统为:
**** List of PLAYBACK Hardware Devices ****
card 0: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM] Subdevices: 8/8 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 Subdevice #2: subdevice #2 Subdevice #3: subdevice #3 Subdevice #4: subdevice #4 Subdevice #5: subdevice #5 Subdevice #6: subdevice #6 Subdevice #7: subdevice #7card 0: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM] Subdevices: 8/8 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 Subdevice #2: subdevice #2 Subdevice #3: subdevice #3 Subdevice #4: subdevice #4 Subdevice #5: subdevice #5 Subdevice #6: subdevice #6 Subdevice #7: subdevice #7card 1: IntelALSASSP [IntelALSASSP], device 0: BT_DEVICE [IntelALSASSP] Subdevices: 1/1 Subdevice #0: subdevice #0card 1: IntelALSASSP [IntelALSASSP], device 2: BUILTIN_DEVICE [IntelALSASSP] Subdevices: 1/1 Subdevice #0: subdevice #0card 2: cloverviewaudio [cloverview_audio], device 0: 4 [] Subdevices: 2/2 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1card 2: cloverviewaudio [cloverview_audio], device 1: Voice rt5640-aif2-1 [] Subdevices: 1/1 Subdevice #0: subdevice #0card 2: cloverviewaudio [cloverview_audio], device 3: BTSCO snd-soc-dummy-dai-3 [] Subdevices: 1/1 Subdevice #0: subdevice #0card 2: cloverviewaudio [cloverview_audio], device 4: VOIP rt5640-aif2-4 [] Subdevices: 1/1 Subdevice #0: subdevice #0card 2: cloverviewaudio [cloverview_audio], device 5: IFX_MODEM_MIXING snd-soc-dummy-dai-5 [] Subdevices: 1/1 Subdevice #0: subdevice #0card 2: cloverviewaudio [cloverview_audio], device 6: virtual-stream rt5640-aif1-6 [] Subdevices: 1/1 Subdevice #0: subdevice #0card 2: cloverviewaudio [cloverview_audio], device 7: CTP Probe snd-soc-dummy-dai-7 [] Subdevices: 1/1 Subdevice #0: subdevice #0由于我的codec 为alc5640,所以
从上面得知alc5640挂在card2上,所以以后我们当配置amixer 5640时就-c 2 就对了。2. alsa_amixer的用法
alsa_amixer -h //一样的help,这里不列了。
用alc5640进行mixer控制的用法:
# alsa_amixer -c 2 controls
如下:
alsa_amixer -c 2 controls
numid=35,iface=MIXER,name='Headphone Switch'numid=20,iface=MIXER,name='Mono ADC Capture Volume'numid=122,iface=MIXER,name='Mono ADC L1 Mux'numid=123,iface=MIXER,name='Mono ADC L2 Mux'numid=114,iface=MIXER,name='Mono ADC MIXL ADC1 Switch'numid=115,iface=MIXER,name='Mono ADC MIXL ADC2 Switch'numid=112,iface=MIXER,name='Mono ADC MIXR ADC1 Switch'numid=113,iface=MIXER,name='Mono ADC MIXR ADC2 Switch'numid=121,iface=MIXER,name='Mono ADC R1 Mux'numid=120,iface=MIXER,name='Mono ADC R2 Mux'numid=93,iface=MIXER,name='Mono DAC MIXL DAC L1 Switch'numid=94,iface=MIXER,name='Mono DAC MIXL DAC L2 Switch'numid=95,iface=MIXER,name='Mono DAC MIXL DAC R2 Switch'numid=92,iface=MIXER,name='Mono DAC MIXR DAC L2 Switch'numid=90,iface=MIXER,name='Mono DAC MIXR DAC R1 Switch'numid=91,iface=MIXER,name='Mono DAC MIXR DAC R2 Switch'numid=11,iface=MIXER,name='Mono DAC Playback Volume'numid=44,iface=MIXER,name='Mono MIX BST1 Switch'numid=41,iface=MIXER,name='Mono MIX DAC L2 Switch'numid=40,iface=MIXER,name='Mono MIX DAC R2 Switch'numid=43,iface=MIXER,name='Mono MIX OUTVOL L Switch'numid=42,iface=MIXER,name='Mono MIX OUTVOL R Switch'numid=85,iface=MIXER,name='Mono dacr Mux'numid=8,iface=MIXER,name='Mono Playback Switch'numid=21,iface=MIXER,name='ADC Boost Gain'numid=24,iface=MIXER,name='ADC IF1 Data Switch'numid=26,iface=MIXER,name='ADC IF2 Data Switch'numid=18,iface=MIXER,name='ADC Capture Switch'numid=19,iface=MIXER,name='ADC Capture Volume'numid=22,iface=MIXER,name='Class D SPK Ratio Control'numid=25,iface=MIXER,name='DAC IF1 Data Switch'numid=27,iface=MIXER,name='DAC IF2 Data Switch'numid=103,iface=MIXER,name='DAC L2 Mux'numid=107,iface=MIXER,name='DAC MIXL INF1 Switch'numid=106,iface=MIXER,name='DAC MIXL Stereo ADC Switch'numid=105,iface=MIXER,name='DAC MIXR INF1 Switch'numid=104,iface=MIXER,name='DAC MIXR Stereo ADC Switch'numid=102,iface=MIXER,name='DAC R2 Mux'numid=10,iface=MIXER,name='DAC1 Playback Volume'numid=9,iface=MIXER,name='DAC2 Playback Switch'numid=108,iface=MIXER,name='DAI select'numid=88,iface=MIXER,name='DIG MIXL DAC L1 Switch'numid=89,iface=MIXER,name='DIG MIXL DAC L2 Switch'numid=86,iface=MIXER,name='DIG MIXR DAC R1 Switch'numid=87,iface=MIXER,name='DIG MIXR DAC R2 Switch'numid=23,iface=MIXER,name='DMIC Switch'numid=37,iface=MIXER,name='Ext Spk L Switch'numid=38,iface=MIXER,name='Ext Spk R Switch'numid=3,iface=MIXER,name='HP Playback Switch'numid=4,iface=MIXER,name='HP Playback Volume'numid=50,iface=MIXER,name='HPO MIX DAC1 Switch'numid=49,iface=MIXER,name='HPO MIX DAC2 Switch'numid=51,iface=MIXER,name='HPO MIX HPVOL Switch'numid=36,iface=MIXER,name='Headset Mic Switch'numid=111,iface=MIXER,name='IF2 ADC L Mux'numid=110,iface=MIXER,name='IF2 ADC R Mux'numid=17,iface=MIXER,name='IN Capture Volume'numid=13,iface=MIXER,name='IN1 Boost'numid=12,iface=MIXER,name='IN1 Mode Control'numid=15,iface=MIXER,name='IN2 Boost'numid=14,iface=MIXER,name='IN2 Mode Control'numid=39,iface=MIXER,name='Int Mic Switch'numid=45,iface=MIXER,name='LOUT MIX DAC L1 Switch'numid=46,iface=MIXER,name='LOUT MIX DAC R1 Switch'numid=47,iface=MIXER,name='LOUT MIX OUTVOL L Switch'numid=48,iface=MIXER,name='LOUT MIX OUTVOL R Switch'numid=29,iface=MIXER,name='LPE IHF mixer'numid=30,iface=MIXER,name='LPE headset mixer'numid=6,iface=MIXER,name='OUT Channel Switch'numid=69,iface=MIXER,name='OUT MIXL BST1 Switch'numid=68,iface=MIXER,name='OUT MIXL BST3 Switch'numid=74,iface=MIXER,name='OUT MIXL DAC L1 Switch'numid=73,iface=MIXER,name='OUT MIXL DAC L2 Switch'numid=72,iface=MIXER,name='OUT MIXL DAC R2 Switch'numid=70,iface=MIXER,name='OUT MIXL INL Switch'numid=71,iface=MIXER,name='OUT MIXL REC MIXL Switch'numid=62,iface=MIXER,name='OUT MIXR BST1 Switch'numid=61,iface=MIXER,name='OUT MIXR BST2 Switch'numid=60,iface=MIXER,name='OUT MIXR BST3 Switch'numid=65,iface=MIXER,name='OUT MIXR DAC L2 Switch'numid=67,iface=MIXER,name='OUT MIXR DAC R1 Switch'numid=66,iface=MIXER,name='OUT MIXR DAC R2 Switch'numid=63,iface=MIXER,name='OUT MIXR INR Switch'numid=64,iface=MIXER,name='OUT MIXR REC MIXR Switch'numid=5,iface=MIXER,name='OUT Playback Switch'numid=7,iface=MIXER,name='OUT Playback Volume'numid=138,iface=MIXER,name='RECMIXL BST1 Switch'numid=137,iface=MIXER,name='RECMIXL BST2 Switch'numid=136,iface=MIXER,name='RECMIXL BST3 Switch'numid=134,iface=MIXER,name='RECMIXL HPOL Switch'numid=135,iface=MIXER,name='RECMIXL INL Switch'numid=139,iface=MIXER,name='RECMIXL OUT MIXL Switch'numid=132,iface=MIXER,name='RECMIXR BST1 Switch'numid=131,iface=MIXER,name='RECMIXR BST2 Switch'numid=130,iface=MIXER,name='RECMIXR BST3 Switch'numid=128,iface=MIXER,name='RECMIXR HPOR Switch'numid=129,iface=MIXER,name='RECMIXR INR Switch'numid=133,iface=MIXER,name='RECMIXR OUT MIXR Switch'numid=28,iface=MIXER,name='Register Control'numid=109,iface=MIXER,name='SDI select'numid=82,iface=MIXER,name='SPK MIXL DAC L1 Switch'numid=83,iface=MIXER,name='SPK MIXL DAC L2 Switch'numid=81,iface=MIXER,name='SPK MIXL INL Switch'numid=84,iface=MIXER,name='SPK MIXL OUT MIXL Switch'numid=80,iface=MIXER,name='SPK MIXL REC MIXL Switch'numid=77,iface=MIXER,name='SPK MIXR DAC R1 Switch'numid=78,iface=MIXER,name='SPK MIXR DAC R2 Switch'numid=76,iface=MIXER,name='SPK MIXR INR Switch'numid=79,iface=MIXER,name='SPK MIXR OUT MIXR Switch'numid=75,iface=MIXER,name='SPK MIXR REC MIXR Switch'numid=59,iface=MIXER,name='SPOL MIX BST1 Switch'numid=56,iface=MIXER,name='SPOL MIX DAC L1 Switch'numid=55,iface=MIXER,name='SPOL MIX DAC R1 Switch'numid=58,iface=MIXER,name='SPOL MIX SPKVOL L Switch'numid=57,iface=MIXER,name='SPOL MIX SPKVOL R Switch'numid=54,iface=MIXER,name='SPOR MIX BST1 Switch'numid=52,iface=MIXER,name='SPOR MIX DAC R1 Switch'numid=53,iface=MIXER,name='SPOR MIX SPKVOL R Switch'numid=32,iface=MIXER,name='SSP BT Master Mode'numid=34,iface=MIXER,name='SSP Modem Master Mode'numid=33,iface=MIXER,name='SSP VOIP Master Mode'numid=31,iface=MIXER,name='SST Probe Byte Control'numid=16,iface=MIXER,name='Speaker Boost'numid=1,iface=MIXER,name='Speaker Playback Switch'numid=2,iface=MIXER,name='Speaker Playback Volume'numid=125,iface=MIXER,name='Stereo ADC L1 Mux'numid=127,iface=MIXER,name='Stereo ADC L2 Mux'numid=118,iface=MIXER,name='Stereo ADC MIXL ADC1 Switch'numid=119,iface=MIXER,name='Stereo ADC MIXL ADC2 Switch'numid=116,iface=MIXER,name='Stereo ADC MIXR ADC1 Switch'numid=117,iface=MIXER,name='Stereo ADC MIXR ADC2 Switch'numid=124,iface=MIXER,name='Stereo ADC R1 Mux'numid=126,iface=MIXER,name='Stereo ADC R2 Mux'numid=101,iface=MIXER,name='Stereo DAC MIXL ANC Switch'numid=99,iface=MIXER,name='Stereo DAC MIXL DAC L1 Switch'numid=100,iface=MIXER,name='Stereo DAC MIXL DAC L2 Switch'numid=98,iface=MIXER,name='Stereo DAC MIXR ANC Switch'numid=96,iface=MIXER,name='Stereo DAC MIXR DAC R1 Switch'numid=97,iface=MIXER,name='Stereo DAC MIXR DAC R2 Switch'alsa_amixer -c 2 cget numid=2 // 从card2 获得主喇叭当时的音量
alsa_amixer -c 2 cset numid=2 39 // 从card2设置主喇叭的音量=39
alsa_amixer -c 2 cset numid=2 100% // 从card2设置主喇叭的音量=39