VAR-SOM-MX6 Audio record play

VAR-SOM-MX6 - Audio Record/Play

Get information on the Sound Cards

Installed devices:

root@var-som-mx6:~# cat /proc/asound/cards
 0 [tlv320aic3xaudi]: tlv320aic3x-aud - tlv320aic3x-audio
                      tlv320aic3x-audio
 1 [imxhdmisoc     ]: imx-hdmi-soc - imx-hdmi-soc
                      imx-hdmi-soc

List device names:

root@var-som-mx6:~# aplay -L

null
    Discard all samples (playback) or generate zero samples (capture)
sysdefault:CARD=tlv320aic3xaudi
    tlv320aic3x-audio, 
    Default Audio Device
sysdefault:CARD=imxhdmisoc
    imx-hdmi-soc, 
    Default Audio Device
surround40:CARD=imxhdmisoc,DEV=0
    imx-hdmi-soc, 
    4.0 Surround output to Front and Rear speakers
surround41:CARD=imxhdmisoc,DEV=0
    imx-hdmi-soc, 
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=imxhdmisoc,DEV=0
    imx-hdmi-soc, 
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=imxhdmisoc,DEV=0
    imx-hdmi-soc, 
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=imxhdmisoc,DEV=0
    imx-hdmi-soc, 
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers

Audio Playback

Set volume:

$ amixer set PCM 125

Play audio:

$ aplay /usr/share/sounds/alsa/Front_Center.wav

Example:

root@var-som-mx6:~# amixer set PCM 125
Simple mixer control 'PCM',0
  Capabilities: pvolume
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 127
  Mono:
  Front Left: Playback 125 [98%] [-1.00dB]
  Front Right: Playback 125 [98%] [-1.00dB]
root@var-som-mx6:~# aplay /usr/share/sounds/alsa/Front_Center.wav
Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono

Audio Record

$ arecord -f cd -d 10 -D hw:0,0 test.wav
$ aplay test.wav 

Example:

root@var-som-mx6:~# arecord -f cd -d 10 -D hw:0,0 test.wav
Recording WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
root@var-som-mx6:~# ^C
root@var-som-mx6:~# aplay test.wav
Playing WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo

Advanced Controls

amixer shiow all avilable controls. amixer sset sID P set contents for one mixer simple control amixer sget sID get contents for one mixer simple control

amixer sget 'HP DAC' Simple mixer control 'HP DAC',0

 Capabilities: pvolume
 Playback channels: Front Left - Front Right
 Limits: Playback 0 - 118
 Mono:
 Front Left: Playback 71 [60%] [-23.50dB]
 Front Right: Playback 71 [60%] [-23.50dB]

HP DAC is a headphones DAC gain currently set to 60%.

amixer sset 'HP DAC' 117 117

alsctl

 store     <card>  save current driver setup for one or each soundcards
                     to configuration file
 restore   <card>  load current driver setup for one or each soundcards
                     from configuration file

alsactl store -f 123.conf alsactl restore -f 123.conf