I tried to test the audio cape Rev B on BeagleBone Black board, the linux kernel used is 3.14.17 (https://github.com/RobertCNelson/bb-kernel.git, branch am33x-v3.14)
I can play and capture the sound normally with the Audio Cape. File recorded via the Cape is played fine with the Cape output. But thing went wrong when we play the recorded file else where.
On the board, I record audio with arecord commandarecord -t raw -f S16_LE -r 44100 /tmp/1.raw
If we play back the recorded file on the board, it is okaplay -t raw -f S16_LE -r 44100 /tmp/1.raw
But when I copied the recorded file to x86 machine, the speed of the audio changed. The recorded voice is played 1.5 time slower than it actually is.
I tried the same test with USB sound card (record the audio via the Audio Cape and playback via the USB Sound Card), the playback got the same issue that was seen on x86 machine.
It seems like there is something wrong with the clocking. May you please give any suggestions.