Я использую AVFoundation для сканирования QR-кода.Проходя различные уроки, я придумал этот код.Все выглядит хорошо, за исключением небольшой 1-секундной задержки, когда вы запускаете AVFoundation и подключаете выход камеры с желанием View.
import AVFoundation
import UIKit
protocol CameraControllerQRCodeDelegate {
func qrCodefound(qrCodeValue : String,bounds: CGRect)
}
class CameraControllerQRCode :NSObject{
//MARK: - Properties
var delegate : CameraControllerQRCodeDelegate?
var captureSession : AVCaptureSession?
var frontCamera: AVCaptureDevice?
var rearCamera : AVCaptureDevice?
var currentCameraPosition : CameraPosition?
var frontCameraInput : AVCaptureDeviceInput?
var rearCameraInput : AVCaptureDeviceInput?
var rearCaptureInput : AVCaptureInput?
var captureOutput : AVCaptureOutput?
var photoOutput : AVCapturePhotoOutput?
var previewLayer : AVCaptureVideoPreviewLayer?
var photoCaptureCompletionBlock : ((UIImage?,Error?) -> ())?
enum CameraControllerError : Swift.Error{
case captureSessionAlreadyRunning
case captureSessionIsMissing
case inputsAreInvalid
case outputsAreInvalid
case invalidOperation
case noCamerasAvailable
case torchCouldNotBeUsed
case unableToFocus
case unknown
}
public enum CameraPosition {
case front
case rear
}
//Body
func prepare(completionHandler : @escaping (Error?) -> ()){
func createCaptureSession(){
self.captureSession = AVCaptureSession()
}
func configureCaptureDevices() throws {
let session = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: .video, position: .back)
let cameras = session.devices
if cameras.isEmpty { throw CameraControllerError.noCamerasAvailable }
for camera in cameras{
print(camera.deviceType.rawValue)
if camera.position == .front {
self.frontCamera = camera
}
if camera.position == .back {
self.rearCamera = camera
try camera.lockForConfiguration()
camera.focusMode = .continuousAutoFocus
camera.unlockForConfiguration()
print(camera.activeVideoMaxFrameDuration)
}
}
}
func configureDeviceInputs() throws {
guard let captureSession = self.captureSession else { throw CameraControllerError.captureSessionIsMissing}
if let rearCamera = self.rearCamera {
self.rearCameraInput = try AVCaptureDeviceInput(device: rearCamera)
self.rearCaptureInput = try AVCaptureDeviceInput(device: rearCamera)
if captureSession.canAddInput(self.rearCameraInput!){
captureSession.addInput(self.rearCameraInput!)
}else{
throw CameraControllerError.inputsAreInvalid
}
self.currentCameraPosition = .rear
}else if let frontCamera = self.frontCamera {
self.frontCameraInput = try AVCaptureDeviceInput(device: frontCamera)
if captureSession.canAddInput(self.frontCameraInput!){
captureSession.addInput(self.frontCameraInput!)
}else{
throw CameraControllerError.inputsAreInvalid
}
self.currentCameraPosition = .front
}else{
throw CameraControllerError.noCamerasAvailable
}
}
func configurePhotoOutput() throws {
guard let captureSession = self.captureSession else {
throw CameraControllerError.captureSessionIsMissing
}
self.photoOutput = AVCapturePhotoOutput()
self.photoOutput!.setPreparedPhotoSettingsArray([AVCapturePhotoSettings(format: [AVVideoCodecKey:AVVideoCodecType.jpeg])], completionHandler: nil)
if captureSession.canAddOutput(self.photoOutput!){
captureSession.addOutput(self.photoOutput!)
}
//metadataOutput
let metadataOutput = AVCaptureMetadataOutput()
if captureSession.canAddOutput(metadataOutput){
captureSession.addOutput(metadataOutput)
metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
metadataOutput.metadataObjectTypes = [.qr]
}else{
throw CameraControllerError.outputsAreInvalid
}
captureSession.startRunning()
}
DispatchQueue(label: "prepare").async {
do{
createCaptureSession()
try configureCaptureDevices()
try configureDeviceInputs()
try configurePhotoOutput()
}catch{
DispatchQueue.main.async {
completionHandler(error)
}
return
}
DispatchQueue.main.async {
completionHandler(nil)
}
}
}
func displayPreview(on view : UIView) throws {
guard let captureSession = self.captureSession,captureSession.isRunning else {
throw CameraControllerError.captureSessionIsMissing
}
self.previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
guard let previewLayer = self.previewLayer else {
throw CameraControllerError.unknown
}
previewLayer.videoGravity = .resizeAspectFill
previewLayer.connection?.videoOrientation = .portrait
view.layer.insertSublayer(previewLayer, at: 0)
previewLayer.frame = view.frame
}
//Added Code to CameraControllerQRCode
func removePreviewLayer()throws{
guard let previewLayer = self.previewLayer else {
throw CameraControllerError.unknown
return
}
previewLayer.removeFromSuperlayer()
}
func toggle(on:Bool)throws{
guard let device = AVCaptureDevice.default(for: .video) else {
throw CameraControllerError.torchCouldNotBeUsed
}
if device.hasTorch{
do{
try device.lockForConfiguration()
if on == true{
device.torchMode = .on
}else{
device.torchMode = .off
}
device.unlockForConfiguration()
}catch{
throw CameraControllerError.torchCouldNotBeUsed
}
}else{
throw CameraControllerError.torchCouldNotBeUsed
}
}
func autofocus(focusPoint : CGPoint)throws{
if let device = rearCamera{
do{
try device.lockForConfiguration()
device.isFocusModeSupported(.continuousAutoFocus)
device.focusPointOfInterest = focusPoint
device.focusMode = .autoFocus
device.exposurePointOfInterest = focusPoint
device.exposureMode = .continuousAutoExposure
device.unlockForConfiguration()
}catch{
throw CameraControllerError.unableToFocus
}
}
}
}
extension CameraControllerQRCode : AVCaptureMetadataOutputObjectsDelegate{
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
guard let captureSession = captureSession ,captureSession.isRunning else {
print("CaptureSession nil")
return
}
guard !metadataObjects.isEmpty else {
return
}
guard let metadataObject = metadataObjects[0] as? AVMetadataMachineReadableCodeObject else {
print("Error Delegate method 1")
return
}
let qrCodeBounds = metadataObject.bounds
guard let QRCodeRect = previewLayer?.layerRectConverted(fromMetadataOutputRect: qrCodeBounds) else{
return
}
guard let stringValue = metadataObject.stringValue else {
return
}
guard let delegate = delegate else {
print("Delegate : nil")
return
}
delegate.qrCodefound(qrCodeValue: stringValue, bounds: QRCodeRect)
}
}
Проблема возникает, когда вы используете prepare(), а затем displayPreview(on:)
Требуется до 1-2 секунд, чтобы начать показывать фактический выход камеры.
Это желаемое поведение AVFoundation?
Большое спасибо