Why is AudioSettings.DspTime so inaccurate?

Questions & Answers
1

AudioSettings.DspTime doesn’t update every frame or anywhere close to it!

The manual says dspTime is “… much more precise than the time obtained via the Time.time property.” but, if I read DspTime every frame I can see that it stays the exact same value for up to 3-4 frames at a time. Even if I put this code in FixedUpdate (50 fps) it still doesn’t change every frame.

Example Code…

double lastDspTime = 0;

void Update ()
{
	if (AudioSettings.dspTime == lastDspTime)
	{
		Debug.Log ("Duplicate Time: " + lastDspTime);
	}
	lastDspTime = AudioSettings.dspTime;
}

My output looks like this…

...
Duplicate Time: 210.474666666667
Duplicate Time: 210.474666666667
Duplicate Time: 210.496
Duplicate Time: 210.517333333333
Duplicate Time: 210.517333333333
Duplicate Time: 210.517333333333
Duplicate Time: 210.538666666667
Duplicate Time: 210.56
Duplicate Time: 210.56
...

I couldn’t find anyone else asking about it. Is it just me or do other people just not realize or care? Is there some way to fix this?

Unity 5.3.3 & 4.3.2 both do it.

2

You must read AudioSettings.dspTime in OnAudioFilterRead() not in Update().