         if let format = CMSampleBufferGetFormatDescription(sampleBuffer) {
             if var inASBD = CMAudioFormatDescriptionGetStreamBasicDescription(format)?.pointee {
                 
-                print(inASBD)
+                if inASBD.mChannelsPerFrame == 1 {
+                    inASBD.mChannelsPerFrame = 2
+                    self.makeBytesStereo     = true
+                }
                 
                 var outASBD                 = AudioStreamBasicDescription()
                 outASBD.mSampleRate         = inASBD.mSampleRate

                }
                
                duration = CMTimeAdd(self.previousDuration, CMSampleBufferGetDuration(sampleBuffer))
                pcmBufferSize = UInt32(self.pcmBuffer.count)                
            }
            
            self.aacBuffer = [UInt8](repeating: 0, count: Int(pcmBufferSize))

    private var outASBD: AudioStreamBasicDescription?
    
    private var previousDuration = kCMTimeZero
    private var makeBytesStereo  = false
    
    fileprivate var fillComplexCallback: AudioConverterComplexInputDataProc = { (inAudioConverter, 
        ioDataPacketCount, ioData, outDataPacketDescriptionPtrPtr, inUserData) in
