Question How can one keep a continuously looping mic synchronized?

My app continuously processes the latest microphone data. It works for a while but eventually loses sync. I am looking for a way to either re-sync or never lose sync. Either option is fine. I have read a lot of posts here which have gotten me as far as I am. I haven't found anything that completely solves the problem but do apologize if this has already been answered.

The app consists of an AudioListener (named Microphone below) which is assigned a continuous mic clip like this...

Code (CSharp):

1.  
2. Microphone.Stop();
3. Microphone.clip = UnityEngine.Microphone.Start(
4.     micName,
5.     true,
6.     1,
7.     AudioSettings.GetConfiguration().sampleRate);
8. Microphone.Play();
9. Microphone.timeSamples = 0;
10.  

The app implements OnAudioFilterRead which enqueues the data to be processed by the main thread (and the dsp time of the data) like this...

Code (CSharp):

1.  
2. void OnAudioFilterRead(float[] data, int channels)
3. {
4.     // Copy interleaved Microphone channel data
5.     for (var i = 0; i < data.Length; i += 2) {
6.         // Use channel 0, discard channel 1
7.         audioBuffer[i >> 1] = data[i];
8.     }
9.     audioBuffers.Enqueue((AudioSettings.dspTime, audioBuffer));
10. }
11.  

The main thread processes these buffers and calls GetOutputData throwing away the results (to stay in sync) like this...

Code (CSharp):

1.  
2. // Do some processing...
3. AudioListener.GetOutputData(trashBuf, 0);
4.  

As a side note, it seems odd that I need to call GetOutputData since I already have the data. Is there a more direct way to keep the read/write pointers sync'd?

This runs ok for a while but eventually it loses sync. I can see from examining the dsp time that occasionally some buffers are not delivered to OnAudioFilterRead. This problem is easy to repeat when I load scenes (the GameObject that does all this is set to DontDestroyOnLoad), and probably other times as well.

I would like to be able to re-sync whenever I detect a buffer has been skipped. Can anyone explain the sequence to restart all this so that its back in sync?

 

I guess I finally realized at the end of writing the original post that staying in sync was a fools errand and it would be better to be able to detect and recover from syncloss. Restarting the mic turns out to be a lot like starting it in the first place This seems to be working now.

Code (CSharp):

1. public static void RestartMic()
2. {
3.     Microphone.Stop();
4.     Microphone.clip = UnityEngine.Microphone.Start(
5.         MicName,
6.         true,
7.         MIC_LOOP_TIME,
8.         AudioSettings.GetConfiguration().sampleRate);
9.     Microphone.Play();
10.     Microphone.timeSamples = 0;
11.     Debug.Log($"mic restarted");
12. }
13.