如何在 Swift 中使用 avfoundation 录制视频?

How to record a video with avfoundation in Swift?

我想知道如何在 Swift 中使用 AVFoundation 录制视频。我已经创建了一个自定义相机,但我只知道如何用它拍摄静态照片,但我不知道如何录制视频。据我了解,您必须使用 AVCaptureVideoDataOutput 从记录中获取数据,但我不知道如何开始记录和实现委托方法。

整个 AVFoundation 编程 Guide/Still 和视频媒体捕获都在 Objective-C 中,我似乎无法破译它。这是我完成此任务的尝试:

首先我设置了 camera/capture 会话

override func viewDidLoad() {
    super.viewDidLoad()

    captureSession.sessionPreset = AVCaptureSessionPresetHigh
    let devices = AVCaptureDevice.devices()
    for device in devices {
        if (device.hasMediaType(AVMediaTypeVideo)) {
            if(device.position == AVCaptureDevicePosition.Back) {
                captureDevice = device as? AVCaptureDevice
                if captureDevice != nil {
                    beginSession()
                }
            }
        }
    }

}

然后一旦 beginSession() 被调用,我就会设置实时提要

func beginSession() {
    var err : NSError? = nil
    captureSession.addInput(AVCaptureDeviceInput(device: captureDevice, error: &err))
    if err != nil {
        println("error: \(err?.localizedDescription)")
    }
    previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
    self.cameraView.layer.addSublayer(previewLayer)
    self.cameraView.bringSubviewToFront(takePhotoButton)
    self.cameraView.bringSubviewToFront(self.snappedPicture)
    self.cameraView.bringSubviewToFront(self.backButton)
    previewLayer?.frame = self.cameraView.layer.frame
    captureSession.startRunning()
}

这是我卡住的地方,用户按下记录以实际录制和捕获视频:

@IBAction func takeVideoAction(sender: AnyObject) {

    var recordingDelegate:AVCaptureFileOutputRecordingDelegate? = self

    var videoFileOutput = AVCaptureMovieFileOutput()
    self.captureSession.addOutput(videoFileOutput)

    let filePath = NSURL(fileURLWithPath: "filePath")

    videoFileOutput.startRecordingToOutputFileURL(filePath, recordingDelegate: recordingDelegate)

}

然后我打电话给self.videoFileOutput.stopRecording()

最后是委托方法

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

func captureOutput(captureOutput: AVCaptureFileOutput!, didStartRecordingToOutputFileAtURL fileURL: NSURL!, fromConnections connections: [AnyObject]!) {
    return
}

并没有像你想象的那样发生,因为我不知道如何正确地实现它。

我试过你的代码。当设置一个有意义的 filePath 时,一切正常。像这样更改您的 filePath,您将调用委托方法:

    let documentsURL = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)[0]
    let filePath = documentsURL.URLByAppendingPathComponent("temp")

    // Do recording and save the output to the `filePath`
    videoFileOutput.startRecordingToOutputFileURL(filePath, recordingDelegate: recordingDelegate)