VoiceProcessingIO + Bluetooth = Broken audio output

Hi.


We are using CoreAudio for audio input/output, it's an AudioUnit of subtype "kAudioUnitSubType_VoiceProcessingIO".

The overall setup seems to be fine as there are no errors reported back and iput/output using mic/speaker and cable/USB headsets are working fine.


But, when it comes to BT headset, the output audio is very bad/crackling. The console starts firing up and duming a lot of errors (which seems undocumented):


2016-11-17 09:19:22.102844 <RedactedAppId>[37219:23148803] [vp] 17: >vp> SERIOUS AUDIO STREAM CORRUPTION ERROR DETECTED IN kVPSignalIndex_TsRef : Non-finites present!

2016-11-17 09:19:22.102916 <RedactedAppId>[37219:23148803] [vp] 17: >vp> SERIOUS AUDIO STREAM CORRUPTION ERROR DETECTED IN kVPSignalIndex_EpRef : Non-finites present!

2016-11-17 09:19:22.134782 <RedactedAppId>[37219:23148803] [vp] 17: >vp> SERIOUS AUDIO STREAM CORRUPTION ERROR DETECTED IN kVPSignalIndex_TsRef : Non-finites present!

2016-11-17 09:19:22.134815 <RedactedAppId>[37219:23148803] [vp] 17: >vp> SERIOUS AUDIO STREAM CORRUPTION ERROR DETECTED IN kVPSignalIndex_EpRef : Non-finites present!

2016-11-17 09:19:22.230842 <RedactedAppId>[37219:23148803] [vp] 17: >vp> SERIOUS AUDIO STREAM CORRUPTION ERROR DETECTED IN kVPSignalIndex_TsRef : Non-finites present!

2016-11-17 09:19:22.230918 <RedactedAppId>[37219:23148803] [vp] 17: >vp> SERIOUS AUDIO STREAM CORRUPTION ERROR DETECTED IN kVPSignalIndex_EpRef : Non-finites present!

2016-11-17 09:19:22.230925 <RedactedAppId>[37219:23148803] [vp] 17: >vp> SERIOUS AUDIO STREAM CORRUPTION ERROR DETECTED IN kVPSignalIndex_EpRef : messages were rate limited!

2016-11-17 09:19:22.806789 <RedactedAppId>[37219:23148803] [aqme] 254: aufx/sfcl/appl/0x3/0x0 bogus value in input ABL[0]: -7035271317501939058011179032707596288.000000 (0xfca95e35)


The overall setup is:
Mic input -> AudioConverter (AudioConverterFillComplexBuffer) to 16000.0 PCM -> AudioConverter (custom) to desired codec (RTP/VoIP)

AudioConverter (custom) from desired codec (RTP/VoIP) to 16000.0 PCM-> AudioConverter (AudioConverterFillComplexBuffer) to 44100.0 PCM -> Output


I've read the threads on the forum on setting up VoiceProcessingIO and I'm setting up my AudioUnit according to them. It can't be completely wrong as IO works find for everything except BT headsets (Jabra, Plantronics, Sony).


To make things even worse: IO for BT seems fine on a Mac running 10.11 El Capitan.


Has anyone noticed similar behaviour? Is there something we can do about that?