AVAudioFile

gistfile1.txt

import AVFoundation

private let _singletonInstance = AudioController()

class AudioController {
    
    class var sharedInstance: AudioController {
        return _singletonInstance
    }

    let audioEngine: AVAudioEngine = AVAudioEngine()
    let input: AVAudioInputNode
    let output: AVAudioOutputNode
    let inputFormat: AVAudioFormat
    var isMonitoring: Bool
    var isRecording: Bool
    var audioFile: AVAudioFile!
    
    init() {
        input = audioEngine.inputNode
        output = audioEngine.outputNode
        inputFormat = input.inputFormatForBus(0)
        isMonitoring = false
        isRecording = false
    }
    
    func monitorInput() -> NSError? {
        if (audioEngine.running) {
            audioEngine.pause()
        }
        
        audioEngine.connect(input, to: output, format: inputFormat)

        var error: NSError?
        audioEngine.startAndReturnError(&error)
        if error == nil {
            isMonitoring = true
        } else {
            isMonitoring = false
        }
        return error
    }
    
    func stopMonitoringInput() -> NSError? {
        if (audioEngine.running) {
            audioEngine.pause()
        }
        
        audioEngine.disconnectNodeOutput(input)
        
        var error: NSError?
        audioEngine.startAndReturnError(&error)
        if error == nil {
            isMonitoring = false
        } else {
            isMonitoring = true
        }
        return error
    }
    
    func startRecording() {
        
        let url = fileUtilDocumentsDirectoryURLWithFilename("test.aiff")
        
        let settings =
        [AVFormatIDKey: kAudioFormatLinearPCM,
            AVSampleRateKey: inputFormat.sampleRate,
            AVNumberOfChannelsKey: 2,
            AVLinearPCMBitDepthKey : 32,
            AVLinearPCMIsBigEndianKey : false,
            AVLinearPCMIsFloatKey : true,
            AVLinearPCMIsNonInterleaved : false];
        
        var error : NSError?
        self.audioFile = AVAudioFile(forWriting: url, settings: settings, commonFormat: AVAudioCommonFormat.PCMFormatFloat32, interleaved: false, error: &error)

        if (error != nil) {
            println(String(format: "error creating audio file %@", error!))
            return
        }
        
        println("recording to file: " + url!.absoluteString!)
        
        input.installTapOnBus(0, bufferSize: 4096, format: nil) { (buffer, when) -> Void in
            var writeError: NSError?
            self.audioFile.writeFromBuffer(buffer, error: &writeError)
        }
        
        isRecording = true
    }
    
    func stopRecording() {
        
        input.removeTapOnBus(0)
        isRecording = false
    }
}