Calls to WASAPI's SetAudioEndpoint() causing odd microphone behavior on WP8

Question

I've been developing a VoIP App for Wp8 that is based on the Chatterbox Sample App. Things were going smoothly until I started working with changing audio endpoints. I posted this (http://social.msdn.microsoft.com/Forums/wpapps/en-US/30b14ab2-1985-4ab0-858b-459757d8b220/setaudioendpoint-to-speakerphone-causes-timing-problem-with-microphone-capture?forum=wpdcapp) a little while ago when I first encountered a timing problem introduced after switching endpoints. I saw the capture timer firing at odd times, which introduced a sort of clicking noise on the far end. I decided to reset and flush the devices ( Stop(), Reset(), Start() ) after switching the endpoint -- this seemed to get rid of the clicking problem.

Now, however, there is a new problem. Occasionally (meaning every 20-30 switches) when switching the endpoint device, the sound on the far end gets "fuzzy" or distorted. Switching the endpoint again (and restarting the devices) seems to get rid of the problem, but I still don't know the root issue here. I've also noticed that when the far end audio is distorted, the near end playback is perfect, which lead me to believe that timing is not an issue.

Have people encountered similar problems when switching audio endpoints, or could there be something else going on?

Answer 1

Microsoft has told me this is a reported bug on WinRT and they are looking into it now.