Pitcher Shifter test (Swift)

Pitcher Shifter test (Swift)

//
//  ViewController.swift
//  PitcherShifterSwift
//
//  Created by Damon Jones on 11/9/14.
//  Copyright (c) 2014 Damon Jones. All rights reserved.
//

import UIKit
import AVFoundation

class ViewController: UIViewController {
    let engine: AVAudioEngine = AVAudioEngine()
    let player: AVAudioPlayerNode = AVAudioPlayerNode()
    let file: AVAudioFile! = nil
    let pitchEffect: AVAudioUnitTimePitch = AVAudioUnitTimePitch()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        
        var error: NSError? = nil

        // Get the URL of the file
        let url: NSURL? = NSBundle.mainBundle().URLForResource("Audio File", withExtension: "m4a")
        
        if nil == url {
            println("Invalid file URL")
            abort()
        }
        
        // Create the file object for reading
        let file = AVAudioFile(forReading: url, error: &error)
        if nil != error {
            println(error)
            abort()
        }

        // Set the pitch-shift amount (100 cents = 1 semitone)
        pitchEffect.pitch = 100.0 // +1 semitone
        pitchEffect.overlap = 12.0 // more overlapping windows
        
        // Add nodes to engine
        engine.attachNode(player)
        engine.attachNode(pitchEffect)
        
        // Connect the player's output to the effect's input
        engine.connect(player, to: pitchEffect, format: file.processingFormat)
        // Connect the effect's output to the main mixer's input
        engine.connect(pitchEffect, to: engine.mainMixerNode, format: file.processingFormat)
        
        // Schedule the file and start the engine
        player.scheduleFile(file, atTime: nil, completionHandler: nil)
        engine.startAndReturnError(&error)
        
        if nil != error {
            println(error)
            abort();
        }
        
        // Play the file
        player.play()
    }
}