我在我的应用程序中有一个AVCaptureVideoPreviewLayer,它运行良好,并显示与相机应用程序相同的预览视频。我想要实现相机应用程序的2倍变焦功能。如何做到这一点?
基本上,我希望我的预览图层将视频源更改为您在相机应用程序中点击1x图标切换到2x时所看到的比例。
设置预览层
func startSession(){
captureSession = AVCaptureSession()
captureSession?.sessionPreset = AVCaptureSessionPresetPhoto
let backCamera = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)
// Catch error using the do catch block
do {
let input = try AVCaptureDeviceInput(device: backCamera)
if (captureSession?.canAddInput(input) != nil){
captureSession?.addInput(input)
// Setup the preview layer
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
previewLayer?.connection.videoOrientation = AVCaptureVideoOrientation.portrait
tempImageView.layer.addSublayer(previewLayer!)
captureSession?.startRunning()
// Set up AVCaptureVideoDataOutput
let dataOutput = AVCaptureVideoDataOutput()
dataOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as NSString) : NSNumber(value: kCVPixelFormatType_32BGRA as UInt32)]
dataOutput.alwaysDiscardsLateVideoFrames = true
if (captureSession?.canAddOutput(dataOutput) == true) {
captureSession?.addOutput(dataOutput)
}
let queue = DispatchQueue(label: "com.bigbob.videoQueue")
dataOutput.setSampleBufferDelegate(self, queue: queue)
}
} catch _ {
print("Error setting up camera!")
}