我正在使用
Swift基础的MAC OS-X应用程序.用户将选择视频文件,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.如何将矩形中的所选区域视频显示在摄像机右下角的预览图层？
这是输出：
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()
}
这是我想要的输出图像.
假设视频具有720 * 480的尺寸,用户绘制一个矩形,其点是(x1,y1)(x2,y1)(x3,y3)(x4,y4).如何在相机预览图层(右下角)裁剪视频,显示与用户选择的矩形相同的视频？
任何一个帮助如何实现这个功能？我已经花了好几天的时间和疲惫.
注意：我可以通过使用ROI的视频处理在open-CV中执行,但要求是在本地SWIFT语言中执行.
解决方法
我将做的是创建容器图层作为预览图层,并创建预览视频图层作为其子图层.然后,您基本上可以总是调整视频预览图层的大小和位置,使其与矩形/大球员的比例相匹配.
为此,您可以尝试设置相机图层：
func setupCameraPreviewLayer(){
// Create a camera preview layer container which will be used to mask the preview layer
let cameraContainerLayer = AVLayer()
cameraContainerLayer.maskToBounds = true
//place the cameraContainerLayer at right bottom
cameraContainerLayer.frame.size.width = 100 // Change this to whatever size you'd like your preview to be. The preview layer will have the same width/height ratio as the player layer
cameraContainerLayer.frame.size.height = cameraContainerLayer.frame.size.width * self.player.framesize.height / self.player.framesize.width
cameraContainerLayer.frame.origin.x = self.player.frame.size.width - cameraContainerLayer.frame.size.width
cameraContainerLayer.frame.origin.y = self.player.frame.size.height - cameraContainerLayer.frame.size.height
// Create the camera preview layer
cameraPreviewLayer = AVPlayerLayer(player: self.player.player)
//place the cameraPreview layer so that the container layer has the same size ratio as does the selected rectangle to the big preview layer
let widthRatio = self.rectangleLayer.bounds.size.width / rect.size.width // rect is the CGRect of the rectangle that the user draw
let heightRatio = self.rectangleLayer.bounds.size.height / rect.size.height // rect is the CGRect of the rectangle that the user draw
cameraPreviewLayer.frame.size.width = cameraContainerLayer.bounds.size.width * widthRatio
cameraPreviewLayer.frame.size.height = cameraContainerLayer.bounds.size.height * heightRatio
cameraPreviewLayer.frame.origin.x = //calculate the right X in here based on the widthRatio
cameraPreviewLayer.frame.origin.y = //calculate the right X in here based on the widthRatio
cameraContainerLayer.addSublayer(cameraPreviewLayer)
}
这样的事情应该做的伎俩
P.S：上面的代码没有被测试和/或完成.这只是你应该在正确的轨道上开始的事情
