View source for Debian DART-MX8M Audio record play

<!-- Set release according to "release" parameter in URL and use RELEASE_SUMO_V1.0_DART-MX8M as default
--> {{#vardefine:RELEASE_PARAM|{{#urlget:release}}}} <!--
--> {{#lst:Debian_Platform_Customization|{{#var:RELEASE_PARAM|RELEASE_BUSTER_V1.0_DART-MX8M-MINI}}}} <!--
--> {{PageHeader|{{#var:HARDWARE_NAME}} Audio Record/Play}} {{DocImage|category1=Debian|category2={{#var:HARDWARE_NAME}}}} __toc__
= Get information on the Sound Cards =
Installed devices:
<pre>
# cat /proc/asound/cards
 0 [wm8904audio      ]: wm8904-audio - wm8904-audio
                      wm8904-audio
</pre>
List device names for playback:
<pre>
# aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
pulse
    PulseAudio Sound Server
sysdefault:CARD=wm8904audio
    wm8904-audio, 
    Default Audio Device
</pre>

= Audio Playback =
PulseAudio needs to be stopped to run amixer commands. 
 # systemctl stop pulseaudio
Set PCM volume (main volume of audio codec), range :0-63<br> 
<pre>
# amixer set Headphone 35
</pre>
Play audio:
<pre>
# aplay /usr/share/sounds/alsa/Front_Center.wav
</pre>
Example:
<pre>
# systemctl stop pulseaudio;amixer set set Headphone 35
Simple mixer control 'Headphone',0
  Capabilities: volume pswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 63
  Front Left: 35 [56%] [-22.00dB] Playback [on]
  Front Right: 35 [56%] [-22.00dB] Playback [on]

# 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
</pre>

= Audio Record and Play, Line-in Jack=
PulseAudio needs to be stopped to run amixer commands. 
 # systemctl stop pulseaudio
Set PCM volume (main volume of audio codec), range :0-63
<pre>
# amixer set Headphone 35
</pre>
Set capture input source to ADC
<pre>
# amixer set 'Capture Input' ADC
</pre>
Set DMIC Mux to DMIC2
<pre>
# amixer set 'DMIC Mux' DMIC2
</pre>
Record CD quality audio for 10 seconds into file test.wav
<pre>
# arecord -f cd -d 10 test.wav
</pre>
Play the recorded file
<pre>
# aplay test.wav 
</pre>
Example:
<pre>
# systemctl stop pulseaudio; amixer set set Headphone 35
Simple mixer control 'Headphone',0
  Capabilities: volume pswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 63
  Front Left: 35 [56%] [-22.00dB] Playback [on]
  Front Right: 35 [56%] [-22.00dB] Playback [on]
# amixer set 'Capture Input' ADC                                                                                                                                                         
Simple mixer control 'Capture Input',0
  Capabilities: enum
  Items: 'ADC' 'DMIC'
  Item0: 'ADC'
# amixer set 'DMIC Mux' DMIC2
Simple mixer control 'DMIC Mux',0
  Capabilities: enum
  Items: 'DMIC1' 'DMIC2'
  Item0: 'DMIC2'
# arecord -f cd -d 10 test.wav
Recording WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
# aplay test.wav
Playing WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
</pre>

= Audio Record and Play, DMIC =
PulseAudio needs to be stopped to run amixer commands. 
 # systemctl stop pulseaudio
Set Headphones volume, range :0-63
<pre>
# amixer set Headphone 35
</pre>
Set capture input source to DMIC
<pre>
# amixer set 'Capture Input' DMIC
</pre>
Set DMIC Mux to DMIC1
<pre>
# amixer set 'DMIC Mux' DMIC1
</pre>
Record CD quality audio for 10 seconds into file test.wav
<pre>
# arecord -f cd -d 10 test.wav
</pre>
Play the recorded file
<pre>
# aplay test.wav 
</pre>
Example:
<pre>
 # systemctl stop pulseaudio;amixer set set Headphone 35
Simple mixer control 'Headphone',0
  Capabilities: volume pswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 63
  Front Left: 35 [56%] [-22.00dB] Playback [on]
  Front Right: 35 [56%] [-22.00dB] Playback [on]
# amixer set 'Capture Input' DMIC                                                                                                                                                         
Simple mixer control 'Capture Input',0
  Capabilities: enum
  Items: 'ADC' 'DMIC'
  Item0: 'DMIC'
# amixer set 'DMIC Mux' DMIC1
Simple mixer control 'DMIC Mux',0
  Capabilities: enum
  Items: 'DMIC1' 'DMIC2'
  Item0: 'DMIC1'
# arecord -f cd -d 10 test.wav
Recording WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
# aplay test.wav
Playing WAVE 'test.wav' : Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
</pre>

= Advanced Controls =
amixer without a parameter will show all available controls.
PulseAudio needs to be stopped to run amixer commands. 
 # systemctl stop pulseaudio
For example:
<pre>
# systemctl stop pulseaudio;amixer
Simple mixer control 'Headphone',0
  Capabilities: volume pswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 63
  Front Left: 35 [56%] [-22.00dB] Playback [on]
  Front Right: 35 [56%] [-22.00dB] Playback [on]
Simple mixer control 'Headphone ZC',0
  Capabilities: pswitch
  Playback channels: Front Left - Front Right
  Mono:
  Front Left: Playback [on]
  Front Right: Playback [on]
Simple mixer control 'Line Output',0
  Capabilities: volume pswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 63
  Front Left: 57 [90%] [0.00dB] Playback [on]
  Front Right: 57 [90%] [0.00dB] Playback [on]
Simple mixer control 'Line Output ZC',0         
  Capabilities: pswitch                         
  Playback channels: Front Left - Front Right   
  Mono:                                         
  Front Left: Playback [on]                     
  Front Right: Playback [on]                    
Simple mixer control 'Capture',0                
  Capabilities: cvolume cswitch               
  Capture channels: Front Left - Front Right  
  Limits: Capture 0 - 31                      
  Front Left: Capture 24 [77%] [on]           
  Front Right: Capture 24 [77%] [on]          
Simple mixer control 'Capture Input',0        
  Capabilities: enum                          
  Items: 'ADC' 'DMIC'                         
  Item0: 'DMIC'
...                            
</pre>
Options:
<pre>
amixer   sset sID P      set contents for one mixer simple control
amixer   sget sID        get contents for one mixer simple control
</pre>

For example:
<pre>
#systemctl stop pulseaudio;amixer sget 'Capture'                                                                                         
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 31
  Front Left: Capture 24 [77%] [on]
  Front Right: Capture 24 [77%] [on]
  # amixer sset 'Capture' 25                                                                                      
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 31
  Front Left: Capture 25 [81%] [on]
  Front Right: Capture 25 [81%] [on]
</pre>
Capture  currently now set to 81%.

= Save / restore system's audio settings =
alsactl store stores all alsamixer settings into a file<br>
alsctl
Options:
<pre>
  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
</pre>
Example:
<pre>
# systemctl stop pulseaudio
# alsactl store -f 123.conf
# amixer 
# alsactl restore -f 123.conf
</pre>