I'm doing a loopback test application: play/record a stream with WASAPI
exclusive mode, and connect playback and recoring by I2S on a USB 2.0 audio
device, set both the same sampling rate, bit depth, channel number and
volume to 0dB in order to get a BitPerfect loopback test.
This works fine in normal situation--run loopback test for 5 minutes, stop,
then run it again, over 50 times there had no glitch occurred.
But when the system resume from S3 or S4, the audio glitch sometimes
occurred. I checked my application's log, it seems the audio glitch always
occured at about 1 minute after system resumed (if didn't occur at 1
minute, the next 4 minutes will nerver have any audio glitch for a 5
minutes test). Attachment is screenshot of recorded wave.
Does anyone have any idea about this?
My testing platform information:
OS: Windows 10 Pro, build 17134.191.
USB 2.0 audio device at USB 3.0 port, using Microsoft UAC 2.0 driver.
Playback/recording format: 192KHz, 24bit
Description: PNG image