How to get a specific video area in Swift AVPlayer? - ios

Question

I am working on Swift base MAC OS-X application. The user will choose a video file and the NSView Controller will play the video using AVPlayerView. The user can draw a rectangle over the AVPlayerView and I have achieved this functionality. How to show the selected area video in a rectangle to a camera Preview Layer at right bottom?
Here is the output:
Here is the Code:
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()
}
Here is the desire output picture which I wants.
Suppose Video has a size 720*480, user has draw a rectangle and its points are (x1, y1) (x2,y1) (x3,y3) (x4,y4). How could I crop a video in camera Preview layer(at right bottom) which shows the video of area same as rectangle selected by the user?
Any one help how to achieve this functionality? I have spend many days on this and exhaust.
Note: I can do it in open-CV by video processing using ROI, but the requirement is to do it in native SWIFT Language.