IOS camera zoom not working swift - xcode - ios

Question

I have iPhone 13 pro with iOS version 15.5. I am using XCode version 13.3.1.
I am trying to achieve camera zoom with the AVFoundation.
Below is the code I have tried out. The camera device selected is the .builtInTripleCamera. I would like to take macro images. I am trying out different zoom factors like 1.0, 3.0 and 15.0. But the camera preview is not changing. I am not sure whether this is the current method to obtain zoomed-in camera preview as well as the output. Did anybody manage to correctly set the camera zoom factor with AVFoundation?
private let captureSession = AVCaptureSession()
private lazy var previewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
private let videoDataOutput = AVCaptureVideoDataOutput()
private var cameraDevice: AVCaptureDevice?
override func viewDidLoad() {
super.viewDidLoad()
self.setCameraInput()
self.setCameraOutput()
self.showCameraFeed()
self.captureSession.beginConfiguration()
self.captureSession.sessionPreset = AVCaptureSession.Preset.high;
self.captureSession.commitConfiguration()
self.captureSession.startRunning()
}
private func showCameraFeed() {
self.previewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
self.view.layer.insertSublayer(self.previewLayer, at: 1)
self.previewLayer.frame = self.view.frame
// self.view.addGestureRecognizer(pgr)
}
private func setCameraInput() {
let deviceTypes: [AVCaptureDevice.DeviceType]
if #available(iOS 13, *) {
deviceTypes = [.builtInTripleCamera, .builtInDualWideCamera, .builtInDualCamera, .builtInWideAngleCamera]
} else {
deviceTypes = [.builtInDualCamera, .builtInWideAngleCamera]
}
let session = AVCaptureDevice.DiscoverySession(
deviceTypes: deviceTypes,
mediaType: .video,
position: .back
)
guard let device = session.devices.first else {
fatalError("No back camera device found.")
}
cameraDevice = device
addInputToSession(device: cameraDevice!, session: self.captureSession)
}
private func addInputToSession(device:AVCaptureDevice,session:AVCaptureSession){
let cameraInput = try! AVCaptureDeviceInput(device: device)
if(session.canAddInput(cameraInput)){
do{
try device.lockForConfiguration()
cameraInput.device.videoZoomFactor = 15
session.addInput(cameraInput)
device.unlockForConfiguration()
}catch{
print(error)
}
}
}
private func setCameraOutput() {
self.videoDataOutput.videoSettings = [(kCVPixelBufferPixelFormatTypeKey as NSString) : NSNumber(value: kCVPixelFormatType_32BGRA)] as [String : Any]
self.videoDataOutput.alwaysDiscardsLateVideoFrames = true
self.videoDataOutput.setSampleBufferDelegate(self, queue: DispatchQueue(label: "camera_frame_processing_queue"))
self.captureSession.addOutput(self.videoDataOutput)
guard let connection = self.videoDataOutput.connection(with: AVMediaType.video),
connection.isVideoOrientationSupported else { return }
connection.videoOrientation = .portrait
}

Answer 1

Handle camera zoom with pinch recognizer.
cameraDevice.videoZoomFactor
and set it to the recognizer on .began state like this
#objc private func viewPinched(recognizer: UIPinchGestureRecognizer) {
switch recognizer.state {
case .began:
recognizer.scale = cameraDevice.videoZoomFactor
case .changed:
let scale = recognizer.scale
do {
try cameraDevice.lockForConfiguration()
cameraDevice.videoZoomFactor = max(cameraDevice.minAvailableVideoZoomFactor, min(scale, cameraDevice.maxAvailableVideoZoomFactor))
cameraDevice.unlockForConfiguration()
}
catch {
print(error)
}
default:
break
}
}