Сохранение видео на 120/240 кадров в секунду

Question

Я делаю приложение для записи видео на максимальную частоту кадров устройства (т. Е. 120 кадров в секунду на iPhone 5 и 240 в 6 и 6). Мне удалось настроить AVCaptureDevice, чтобы установить maxFrameRateDuration, я печатаю на журналы currentDevice.activeFormat.videoSupportedFrameRateRanges и все отлично работает.

Но когда я пытаюсь сохранить видео, он сохраняет его, но при нормальной частоте кадров, не на 120 или 240 кадров в секунду.

Пожалуйста, помогите мне с этим? Любая помощь приветствуется.

Заранее спасибо.

P.S .: Вот мой полный код до сего пор

import UIKit 
import AVFoundation 
import AVKit 
import AssetsLibrary 

class ViewController: UIViewController, AVCaptureFileOutputRecordingDelegate { 

    @IBOutlet weak var cameraButton:UIButton! 

    let captureSession = AVCaptureSession() 
    var currentDevice:AVCaptureDevice? 
    var videoFileOutput:AVCaptureMovieFileOutput? 
    var cameraPreviewLayer:AVCaptureVideoPreviewLayer? 
    var outputPath: String = "" 
    var backgroundRecordId: UIBackgroundTaskIdentifier = UIBackgroundTaskInvalid 

    var isRecording = false 

    override func viewDidLoad() { 
     super.viewDidLoad() 

     // Preset the session for taking photo in full resolution 
     captureSession.sessionPreset = AVCaptureSessionPresetHigh 

     // Get the available devices that is capable of taking video 
     let devices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo) as! [AVCaptureDevice] 

     // Get the back-facing camera for taking videos 
     for device in devices { 
      if device.position == AVCaptureDevicePosition.Back { 
      currentDevice = device 
       configureDevice() 
      } 
     } 

     let captureDeviceInput:AVCaptureDeviceInput 
     do { 
      captureDeviceInput = try AVCaptureDeviceInput(device: currentDevice) 
     } catch { 
      print(error) 
      return 
     } 

     // Configure the session with the output for capturing video 
     videoFileOutput = AVCaptureMovieFileOutput() 

     // Configure the session with the input and the output devices 
     captureSession.addInput(captureDeviceInput) 
     captureSession.addOutput(videoFileOutput) 

     // Provide a camera preview 
     cameraPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession) 
     view.layer.addSublayer(cameraPreviewLayer!) 
     cameraPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill 
     cameraPreviewLayer?.frame = view.layer.frame 

     // Bring the camera button to front 
     view.bringSubviewToFront(cameraButton) 
     captureSession.startRunning()  
    } 

    func configureDevice() { 

     var bestFormat: AVCaptureDeviceFormat? = nil 
     var bestFrameRateRange: AVFrameRateRange? = nil 
     var bestPixelArea: Int32 = 0 
     for format in currentDevice!.formats { 
      let dims: CMVideoDimensions = CMVideoFormatDescriptionGetDimensions(format.formatDescription) 
      let pixelArea: Int32 = dims.width * dims.height 
      let ranges = format.videoSupportedFrameRateRanges as! [AVFrameRateRange]; 
      for range in ranges { 
       //print ("[",dims.width,",",dims.width,"] : ",range.maxFrameRate); 
       if bestFrameRateRange==nil || range.maxFrameRate > bestFrameRateRange!.maxFrameRate || ((range.maxFrameRate == bestFrameRateRange!.maxFrameRate) && (pixelArea > bestPixelArea)) { 
        bestFormat = format as? AVCaptureDeviceFormat 
        bestFrameRateRange = range 
        bestPixelArea = pixelArea 
       } 
      } 
     }    

     do { 

      try currentDevice!.lockForConfiguration() { 

      currentDevice!.activeFormat = bestFormat 
      currentDevice!.activeVideoMinFrameDuration = bestFrameRateRange!.minFrameDuration 
      currentDevice!.activeVideoMaxFrameDuration = bestFrameRateRange!.minFrameDuration    

     } 
     catch{}   

     print(currentDevice!.activeFormat.videoSupportedFrameRateRanges) 

     currentDevice!.unlockForConfiguration()    
    }  


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

    // MARK: - AVCaptureFileOutputRecordingDelegate methods 

    func captureOutput(captureOutput: AVCaptureFileOutput!, didFinishRecordingToOutputFileAtURL outputFileURL: NSURL!, fromConnections connections: [AnyObject]!, error: NSError!) { 


     if error != nil { 
      print(error) 
      return 
     } 

     let backgroundRecordId: UIBackgroundTaskIdentifier = self.backgroundRecordId 
     self.backgroundRecordId = UIBackgroundTaskInvalid 

     ALAssetsLibrary().writeVideoAtPathToSavedPhotosAlbum(outputFileURL, completionBlock: { 
      (assetURL:NSURL!, error:NSError!) in 
      if error != nil{ 
       print(error) 

      } 

      do { 
       try NSFileManager.defaultManager().removeItemAtURL(outputFileURL) 
      } catch _ { 
      } 

      if backgroundRecordId != UIBackgroundTaskInvalid { 
       UIApplication.sharedApplication().endBackgroundTask(backgroundRecordId) 
      } 

     }) 
     performSegueWithIdentifier("playVideo", sender: outputFileURL) 
    } 

    // MARK: - Segue methods 

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) { 
     if segue.identifier == "playVideo" { 
      let videoPlayerViewController = segue.destinationViewController as! AVPlayerViewController 
      let videoFileURL = sender as! NSURL 
      videoPlayerViewController.player = AVPlayer(URL: videoFileURL) 

     } 
    } 


    // MARK: - Action methods 

    @IBAction func unwindToCamera(segue:UIStoryboardSegue) { 

    } 

    @IBAction func capture(sender: AnyObject) { 
     if !isRecording { 
      isRecording = true 

      UIView.animateWithDuration(0.5, delay: 0.0, options: [.Repeat, .Autoreverse, .AllowUserInteraction], animations: {() -> Void in 
       self.cameraButton.transform = CGAffineTransformMakeScale(0.5, 0.5) 
       }, completion: nil) 

      let outputPath: String = NSTemporaryDirectory() + "output.mov" 
      let outputFileURL = NSURL(fileURLWithPath: outputPath) 
      videoFileOutput?.startRecordingToOutputFileURL(outputFileURL, recordingDelegate: self) 
     } else { 
      isRecording = false 

      UIView.animateWithDuration(0.5, delay: 1.0, options: [], animations: {() -> Void in 
       self.cameraButton.transform = CGAffineTransformMakeScale(1.0, 1.0) 
       }, completion: nil) 
      cameraButton.layer.removeAllAnimations() 

      videoFileOutput?.stopRecording() 

     } 
    }   
} 

Answer 1

Вы звоните configDevice() слишком рано, и конфигурация заменяется.

Вызова configDevice() после того как вы добавили вход Захватных устройств:

// Configure the session with the input and the output devices 
captureSession.addInput(captureDeviceInput) 
configureDevice()