3 Replies
      Latest reply on Aug 20, 2019 4:08 PM by arshiacont
      jml5qh Level 1 Level 1 (0 points)

        Is it recommended to only use one AudioUnit for both input and output? GStreamer makes this really hard and I am trying to use two AudioUnits with subtype = kAudioUnitSubType_VoiceProcessingIO. However, the volume of the audio output is very quiet and I am wondering if that has to do with the multiple AudioUnit objects.

        • Re: Multiple VoiceProcessingIO AudioUnits
          arshiacont Level 1 Level 1 (0 points)

          It is interesting to know that using two Output Type audio units is actually tolerated!

           

          Did you look at the AGC property of kAudioUnitSubType_VoiceProcessingIO ? You might want to turn it off (on by default). Can't think of how it'll handle two outputs

          • Re: Multiple VoiceProcessingIO AudioUnits
            zvba Level 1 Level 1 (0 points)

            Did you manage to work with multiple audiounits ?

            I wonder if I can have voiceprocessing audiounit for Microphone and remoteIO audiounit for Speaker

              • Re: Multiple VoiceProcessingIO AudioUnits
                arshiacont Level 1 Level 1 (0 points)

                @zvba : You can't have a voiceprocessing audiounit with remoteIO. One major reason is that VPIO requires specific AVAudioSession Category/Modes which are not the ones you can use with remoteIO. I had the chance to talk with CoreAudio developpers on this at WWDC.

                This won't get any better with the new AVAudioEngine support for VPIO (which I think uses the good old APIs under the hood).

                A nice solution would be to have enough controls over VPIO to get what we want. All this, for an undetermined future... .