Read encoded frames from audio file with ExtAudioFileSeek and ExtAudioFileRead

Question

This is what I would like to do:

Get audio from the microphone

• Encode it in AAC, G.711 or G.726
• Write the encoded frames to a socket.

And this is how I'm trying to get there:

• I'm getting audio (PCM) from the microphone using TheAmazingAudioEngine and putting it in a buffer;
• Using TPAACAudioConverter I'm reading audio from my buffer and writing to a temp file (AAC);

• In the processing thread of TPAACAudioConverter I replaced this:

  OSStatus status = ExtAudioFileWrite(destinationFile, numFrames, &fillBufList);
  

  with this:

  OSStatus status = ExtAudioFileWrite(destinationFile, numFrames, &fillBufList);
  
  UInt32 framesWritten = numFrames;
  totalFramesWritten += framesWritten;
  
  AudioBufferList readData;
  readData.mNumberBuffers = 1;
  
  ExtAudioFileSeek(destinationFile, totalFramesWritten - framesWritten);
  
  OSStatus readStatus = ExtAudioFileRead(destinationFile, &numFrames, &readData);
  
  ExtAudioFileSeek(destinationFile, totalFramesWritten);
  
  NSLog(@"Bytes read=%d", numFrames);
  

  but what I get is 0 numFrames read from file.

Any idea on what I may be doing wrong or any suggestion on alternative paths to achieve what I need?

Answer 1

I abandoned this approach and reused the AQRecorder class from the SpeakHere example by Apple.

The project is available here https://github.com/robovm/apple-ios-samples/tree/master/SpeakHere.