Dummy audio codec -  play & record on i.MX8MM

Document created by MaxTsai Employee on Jul 4, 2019Last modified by MaxTsai Employee on Jul 8, 2019
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Several customers met problem on audio codec porting. In order to figure out cpu dai setting problem or codec dai problem. Create the dummy codec for test purpose. 


What this dummy codec can do

This dummy codec can play up to 8 channels and record up to 6 channels.

Connect SAI1 TX data pin with SAI1 RX data pin for loopback test.



Verified with i.MX8MM EVK 

Based on Linux BSP L4.14.78



Kernel patch



User space setting




Audio test content




The alsa command for loopback test with multiple channels 

aplay -D surround51:CARD=dummyaudio PCM_48_16_8_160000_1_29_jazzshort.wav | arecord -D surround51:CARD=dummyaudio --disable-channels --disable-format --disable-resample -f S16_LE -r 48000 -c 6 -d 5 -v test.wav

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