title: How to convert AVAudioPCMBuffer to NSData in Objective-C?
body: <p>As the title suggests.</p>
  
  <p>There is an old solution in Swift <a href="https://stackoverflow.com/questions/28048568/convert-avaudiopcmbuffer-to-nsdata-and-back">here</a>. But I have hard time converting to Objective-C. Seems there is no Objective-C equivalent of <code>UnsafeBufferPointer</code> </p>