AVCaptureSession真的很慢

我无法弄清楚为什么我的相机应用程序使用AVFoundation框架真正慢慢拍照。

每个捕获会话大约需要2/3秒。 我认为这是一个记忆问题。

我正在使用Swift 1.1。

我用过的代码：

class ViewController: UIViewController { let captureSession = AVCaptureSession() var previewLayer : AVCaptureVideoPreviewLayer? var captureDevice : AVCaptureDevice? var captureConnection: AVCaptureConnection? var stillImageOutput = AVCaptureStillImageOutput() let targetRegion = CALayer() var currentImage: UIImage? @IBOutlet weak var cameraView: UIImageView! @IBOutlet weak var imageDisplayed: UIImageView! override func viewDidLoad() { super.viewDidLoad() navigationController?.setNavigationBarHidden(true, animated: true) captureSession.sessionPreset = AVCaptureSessionPreset1920x1080 let devices = AVCaptureDevice.devices() for device in devices { if device.hasMediaType(AVMediaTypeVideo) { if device.position == AVCaptureDevicePosition.Back { captureDevice = device as? AVCaptureDevice } } } if captureDevice != nil { println("Device trovato") beginSession() } } func beginSession() { var err: NSError? = nil captureSession.addInput(AVCaptureDeviceInput(device: captureDevice, error: &err)) if err != nil { println("err \(err?.localizedDescription)") return } previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) self.view.layer.addSublayer(previewLayer) previewLayer?.frame = CGRect(x: cameraView.frame.origin.x, y: cameraView.frame.origin.y, width: cameraView.frame.size.width, height: cameraView.frame.size.height) captureSetup() captureSession.startRunning() } func captureSetup() { let outputSetting = NSDictionary(dictionary: [AVVideoCodecKey: AVVideoCodecJPEG]) self.stillImageOutput.outputSettings = outputSetting self.captureSession.addOutput(stillImageOutput) for connection:AVCaptureConnection in self.stillImageOutput.connections as [AVCaptureConnection] { for port:AVCaptureInputPort in connection.inputPorts! as [AVCaptureInputPort] { if port.mediaType == AVMediaTypeVideo { captureConnection = connection as AVCaptureConnection break } } if captureConnection != nil { break } } } var i = 0; func captureScene() { dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), { if self.captureConnection != nil { self.stillImageOutput.captureStillImageAsynchronouslyFromConnection(self.captureConnection, completionHandler:{ (imageSampleBuffer:CMSampleBuffer!, _) -> Void in let imageDataJpeg = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageSampleBuffer) var pickedImage: UIImage = UIImage(data:imageDataJpeg)! if let data = UIImagePNGRepresentation(pickedImage) { let filename = self.getDocumentsDirectory().stringByAppendingPathComponent("\(self.i).png") data.writeToFile(filename, atomically: true) self.i++ } }) } }) } func getDocumentsDirectory() -> NSString { let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true) let documentsDirectory: AnyObject = paths[0] return documentsDirectory as NSString } override func touchesBegan(touches: NSSet, withEvent event: UIEvent) { captureScene() } }