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我正在开发基于 Swift 的 MAC OS-X 应用程序。用户将选择一个视频文件，NSView 控制器将使用 AVPlayerView 播放视频。用户可以在 AVPlayerView 上绘制一个矩形，我已经实现了这个功能。如何将矩形中的选定区域视频显示到右下角的相机预览层？

这是输出： 输出图片

这是代码：

var videoURL = NSURL() // The video file URL by the file chooser
var videoSize = NSSize() // Here the video resolution size will be kept i.e. 720*480
var player:AVPlayerView! // The AVPlayerView to play video

var cameraPreviewLayer:AVPlayerLayer! //The right bottom camera Preview Layer
var rectangleLayer:AVPlayerLayer! // The rectangle that will draw over AVPlayer while mouse dragging

var isClicked = false
var startPoint = NSPoint() // holds the starting point location of mouse pointer while draging

var rect:NSRect!

override func viewDidLoad() {
    super.viewDidLoad()

    self.player = AVPlayerView()

    self.player.frame.origin = CGPoint(x: 0, y: 0)
    self.player.setFrameSize(self.videoSize)

    self.player.player = AVPlayer.playerWithURL(videoURL) as! AVPlayer
    self.view.addSubview(self.player)

    setupRectangle()
    setupCameraPreviewLayer()
}

// intially setup white color rectangle that will draged over AVPlayer
func setupRectangle() {
    self.rectangleLayer = AVPlayerLayer()
    self.rectangleLayer.backgroundColor = NSColor.clearColor().CGColor
    self.rectangleLayer.borderColor = NSColor.whiteColor().CGColor
    self.rectangleLayer.borderWidth = 1.5
    self.rectangleLayer.frame = self.player.bounds
}
// intially setup CameraPreview Layer that will show at right bottom of AVPlayer
func setupCameraPreviewLayer(){
    cameraPreviewLayer = AVPlayerLayer(player: self.player.player)

    //place the cameraPreview layer at right bottom
    cameraPreviewLayer.frame.origin.x = self.player.framesize.width-100
    cameraPreviewLayer.frame.origin.y = self.player.frame.origin.y-100
    cameraPreviewLayer.frame.size.width = 100
    cameraPreviewLayer.frame.size.height = 100
}

override func  mouseDown(theEvent: NSEvent) {
    startPoint = theEvent.locationInWindow
    isClicked = true
    removeCameraPreviewLayer()
}

override func mouseDragged(theEvent: NSEvent) {
    var endPoint = theEvent.locationInWindow

    if( isClicked ){
        rect = NSRect(x: startPoint.x, y: startPoint.y, width: -(startPoint.x-endPoint.x), height: -(startPoint.y-endPoint.y))
        drawCustomRect(rect)
    }
}

override func  mouseUp(theEvent: NSEvent) {
    var endPoint = theEvent.locationInWindow

    if( isClicked ){

// I think we have to do some magic code here
        addCameraPreviewLayer()
    }
    isClicked = false;
}

// redraw the white color rectange over avplayer
func drawCustomRect(rect: NSRect) {
    self.rectangleLayer.frame = rect
    self.player.layer?.addSublayer(self.rectangleLayer)
}

// add Camera PreviewLayer from AVPlayer
func addCameraPreviewLayer() {
    self.player.layer?.addSublayer(self.layer)
}

// remove Camera PreviewLayer from AVPlayer
func removeCameraPreviewLayer() {
    self.cameraPreviewLayer.removeFromSuperlayer()
}

这是我想要的欲望输出图片。 期望的输出

假设视频大小为 720*480，用户绘制了一个矩形，其点为 (x1, y1) (x2,y1) (x3,y3) (x4,y4)。如何在相机预览层（右下角）中裁剪视频，该层显示与用户选择的矩形区域相同的视频？

任何人帮助如何实现此功能？我在这上面花了很多天，筋疲力尽。

注意：我可以通过使用 ROI 的视频处理在 open-CV 中执行此操作，但要求是使用本地 SWIFT 语言执行此操作。

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0 回答 0