Transclusion: Debian: CL-SOM-iMX7: Analog Audio

From Compulab Mediawiki
Revision as of 09:23, 27 March 2018 by Urim (talk)
Jump to: navigation, search


Analog Audio Playback

In order to play back a sound file make use of the aplay application.

  • aplay -L can be used for listing of all pcm devices.

Here is a sample output of aplay -L command: 

root@cl-rootfs:~# aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
default:CARD=clsomimx7
    cl-som-imx7, 
    Default Audio Device
sysdefault:CARD=clsomimx7
    cl-som-imx7, 
    Default Audio Device
dmix:CARD=clsomimx7,DEV=0
    cl-som-imx7, 
    Direct sample mixing device
dsnoop:CARD=clsomimx7,DEV=0
    cl-som-imx7, 
    Direct sample snooping device
hw:CARD=clsomimx7,DEV=0
    cl-som-imx7, 
    Direct hardware device without any conversions
plughw:CARD=clsomimx7,DEV=0
    cl-som-imx7, 
    Hardware device with all software conversions

The next command can be used for audio play back: 

root@cl-rootfs:~# aplay <wav-file>

Audio Input Settings

CL-SOM-iMX7 provides an audio capturing feature from either Mic or Line In input sources. alsamixer or amixer can be used in order to switch between these inputs.

Mic
  • alsamixer
Capture Volume => 100
Line Capture Switch => off
Mic Capture Switch => on
Input Mux => Mic
  • amixer
amixer cset numid=3 31
amixer cset numid=4 0
amixer cset numid=6 1
amixer cset numid=11 1
Line In
  • alsamixer
Capture Volume => 100
Line Capture Switch => on
Mic Capture Switch => off
Input Mux => Line In
  • amixer
amixer cset numid=3 31
amixer cset numid=4 1
amixer cset numid=6 0
amixer cset numid=11 0

Sample Audio Recording

As soon as the correct input values have been set, audio signal can be captured. Here is a sample command that shows the arecord usage for capturing audio signal from the selected input line. 

root@cl-rootfs:~# arecord -f dat -t wav /tmp/out.wav
Retrieved from "https://mediawiki.compulab.com/w/index.php?title=Transclusion:_Debian:_CL-SOM-iMX7:_Analog_Audio&oldid=3956"