Dear all,
I'm trying to get a full understanding of the AVAudioSession, AUGraph and AudioUnit classes in order to build clean and stable audio apps with precisely defined behaviours.
I'm stuck right now on one point : input and output latency (more specifically input latency). Basically, my questions are the following :
1. Where do the latencies come from ?
2. On what parameters do they depend ?
3. How can I reduce them ?
For now, I have noticed that the AudioSession Mode "AVAudioSessionModeMeasurement" results in a very low latency, but with also a very low input volume (and I guess less audio input processing) not really usable for a music app.
On an iPad Air 2, with the built-in microphone :
- with the AVAudioSessionModeMeasurement, I obtain an input latency of 0.1 ms !
- with the AVAudioSessionModeDefault, I obtain on input latency of 58ms !
Any tips about my three questions ?
Thank you
Thomas