如何使用AVFoundation和相机视图更改fps和隐藏状态栏

Question

我正在使用AVFoundation并制作全屏相机视图。我似乎无法改变fps并隐藏状态栏。我希望将fps设置为140 fps（对于iPhone 7），我还希望隐藏状态栏（我在故事板文件和Xcode应用程序设置的“常规”选项卡中更改了它。我提前实现这一谢谢（我用的雨燕3.0，宁愿在斯威夫特3（如果可能）的答案）

视图控制器的代码：？！`类的ViewController：UIViewController的{

@IBOutlet var cameraView: UIImageView! 
let captureSession = AVCaptureSession() 
let stillImageOutput = AVCaptureStillImageOutput() 
var previewLayer : AVCaptureVideoPreviewLayer? 

var captureDevice : AVCaptureDevice? 

func beginSession() { 

    do { 
     try captureSession.addInput(AVCaptureDeviceInput(device: captureDevice)) 
     stillImageOutput.outputSettings = [AVVideoCodecKey:AVVideoCodecJPEG] 

     if captureSession.canAddOutput(stillImageOutput) { 
      captureSession.addOutput(stillImageOutput) 
     } 

    } 
    catch { 
     print("error: \(error.localizedDescription)") 
    } 

    guard let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession) else { 
     print("no preview layer") 
     return 
    } 

    self.view.layer.addSublayer(previewLayer) 
    previewLayer.frame = self.view.layer.frame 
    captureSession.startRunning() 
} 

override func viewWillAppear(_ animated: Bool) { 
    super.viewWillAppear(animated) 

    captureSession.sessionPreset = AVCaptureSessionPresetHigh 

    if let devices = AVCaptureDevice.devices() as? [AVCaptureDevice] { 
     // Loop through all the capture devices on this phone 
     for device in devices { 
      // Make sure this particular device supports video 
      if (device.hasMediaType(AVMediaTypeVideo)) { 
       // Finally check the position and confirm we've got the back camera 
       if(device.position == AVCaptureDevicePosition.back) { 
        captureDevice = device 
        if captureDevice != nil { 
         print("Capture device found") 
         beginSession() 
        } 
       } 
      } 
     } 
    } 


} 

override func didReceiveMemoryWarning() { 
    super.didReceiveMemoryWarning() 
    // Dispose of any resources that can be recreated. 
} 

}

`

Answer 1

1）要隐藏状态栏，您应该添加prefersStatusBarHidden:方法的UIViewController的控制装置：

override var prefersStatusBarHidden : Bool { 
    return true 
} 

2）设定的常数FPS可以使用AVCaptureDevice实例的activeVideoMinFrameDuration和activeVideoMaxFrameDuration属性：

func setFrameRate(_ captureDevice: AVCaptureDevice) { 
    do { 
     try captureDevice.lockForConfiguration() 
     captureDevice.activeVideoMinFrameDuration = CMTimeMake(1, 140) 
     captureDevice.activeVideoMaxFrameDuration = CMTimeMake(1, 140) 
     captureDevice.unlockForConfiguration() 
    } catch { 
     NSLog("An Error occurred: \(error.localizedDescription))") 
    } 
}