just to kind of finalize this thread and excuse for all my posts but perhaps
give this solution to anybody else searching the web on this topic: my feedback
endpoint started to work after I changed the intervals for the endpoints from 4
(corresponding to 1 millisec for a highspeed connection) to 1 (corresponding to
0.125 millisec for a highspeed connection). And also my player application now
reports the slightly modified samplerate as I would expect it.
Von: Johannes Freyberger
Gesendet: Mittwoch, 29. September 2021 18:37
An: 'wdmaudiodev@xxxxxxxxxxxxx' <wdmaudiodev@xxxxxxxxxxxxx>
Betreff: AW: UAC2 driver loaded but no audio endpoints visible
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,