Process audio input from a mobile microphone without saving it to a file

Question

I'm working on a mobile application that can perform basic analysis on audio input from the microphone in real time. However, the usual way to do it using the 'AVAudioRecorder` as shown in this guide and the API requires you to save it to a file first.

Since the app is meant to stay on for a long time and be used multiple times a day, I want to avoid clutter the phone with many audio files or audio files that are too big. However, I can't seem to find the way around it. Searching for solutions on the internet always lead to solutions of how to save an audio to a file, instead of avoiding saving to a file and work with some kind of buffer.

Any pointers would be super helpful!

Answer 1

Both the iOS Audio Unit and the Audio Queue APIs allow one to process short buffers of audio input in real-time without saving to a file.

You can also use a tap on the AVAudioEngine. See Apple's documentation: https://developer.apple.com/library/ios/samplecode/AVAEMixerSample/Introduction/Intro.html

Answer 2

You can use /dev/null as path in the AVAudioRecorder instance. This way it will not save to a file, but just discard the data.

var url = NSUrl.FromString("/dev/null");
var recorder = new AVAudioRecorder(url, settings, out error);