I use webrtc's audio engine to realize the audio capture and playback function on IOS devices. When I start Siri during a call, I receive an audio interruption notification (avaudiosessioninterruptionnotification & avaudiosessioninterruptiontypebegan）, which is in line with expectations.
However, when I quit Siri, I received (avaudiosessioninterruptionnotification & avaudiosessioninterruptiontypeended）and Webrtc will automatically execute the process of restarting audio unit (AudioOutputUnitStart). At this time, it will definitely fail and return error code: - 66637. This error code can't find any relevant information on the Internet. Does anyone know why?
The following is the AVAudiosession information printed by webrtc before turning on audio for the first time:
The following two screenshots are the AVAudioSession information printed by webrtc before calling AudioOutputUnitStart:
Therefore, we can see that the number of channels of audio input has changed after Siri is turned on, from single channel to double channel, and finally to four channels. In addition, the two parameters of outputlatency and inputlatency have also been changed. Is this the reason why the call to AudioOutputUnitStart failed?