I am trying to run one unit_tests project which is given by default after booting linux on i.MX8M Quad EVK board to us for playing the audio file.
I am trying to create raw file for " ./mxc_pdm_test.out " by executing following code :
./mxc_pdm_test.out -device hw:4,0 -output test-audio.raw -rate 16000 -seconds 60
What error i observed is :
ALSA lib ../../../alsa-lib-188.8.131.52/src/pcm/pcm_hw.c:1713:(_snd_pcm_hw_open) Invalid value for card
unable to open pcm device: hw:4,0fail to init alsa pdm -2
Could you please help me to understand this error for me.
What i am missing here ?