I am trying do the audio loopback on i.mx6 sabresd board.
Audio is in from mic port of board, and out to speaker from headphone port.
I used following command:
arecord -Dhw:0,0 -c 2 -f S16_LE -r 44100 | aplay
It is ok that i can hear the audio output from speaker.
But there is a serious delay, i measured with an oscilloscope,
and it is about 400ms.
Now the problem is:
How can i reduce this delay time? My customer's requirement is 100ms.
And I think that the time is costed by the memory copy.
Can bellow flow be achieved？ without the alsa frame work.
audio--->SSI RX FIFO--->SSI TX FIFO---->