Yes, that would have been nice – but as of
<https://docs.microsoft.com/en-us/windows-hardware/drivers/audio/usb-2-0-audio-drivers?source=docs>
https://docs.microsoft.com/en-us/windows-hardware/drivers/audio/usb-2-0-audio-drivers?source=docs
=> “The driver does not support implicit feedback.”
Von: wdmaudiodev-bounce@xxxxxxxxxxxxx Im Auftrag von Wade Dawson
Gesendet: Donnerstag, 30. September 2021 19:50
An: wdmaudiodev@xxxxxxxxxxxxx
Betreff: [wdmaudiodev] Re: AW: UAC2 driver loaded but no audio endpoints visible
Implicit feedback? It’s in the usb audio 2.0 spec. You count samples from an
associated input endpoint to determine the number to send to tge output;
requires input and output to be in the same clock domain (common mclk).
Sent from my iPhone
On Sep 29, 2021, at 12:37 PM, Johannes Freyberger
<jfreyberger@xxxxxxxxxxxxxxxxxxxx <mailto:jfreyberger@xxxxxxxxxxxxxxxxxxxx> >
wrote:
Hi Tim.
thanks again – so when you say none of your USB audio clients use a feedback
endpoint is there another way in usbaudio2.sys to finetune the samplerate for
the playback audiostream (from PC to device) to the internal clock of the
device or even a clock that this device is receiving from somewhere else? Or do
you always do a samplerate conversion (and probably lose bit transparency)
inside your devices in such a case?
Meanwhile I’ve checked in Wireshark USBCap that I can see the feedback endpoint
values being sent to the PC and holding values which are correct if I
understand the spec correctly. But they don’t seem to have any effect.
Thanks and best regards,
Johannes
