AVFoundation会议问题 [英] AVFoundation Session issue
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问题描述
我正在一个需要录制视频的应用程序上工作，我发现了一个由appcoda编写的帮助程序类，这是指向github repo https://github.com/appcoda/FullScreenCamera ，但是我遇到的问题是它在我运行时就出现了，我在控制台中收到一条错误消息，说noCamerasAvailable我还致力于改进代码，但我只是想不通为什么.这是助手类
I am working on an application that requires recording video and I found a helper class written by appcoda and here is a link to the github repo https://github.com/appcoda/FullScreenCamera but the problem I am having with it is that it has when ever I run it, I get an error in the console saying noCamerasAvailable followed by captureSessionIsMissing and I am also commited to Improving the code and I just cannot figure out why. Here is the helper class
class CameraHelper: NSObject {
var captureSession: AVCaptureSession?
var currentCameraPosition: CameraPosition?
var frontCamera: AVCaptureDevice?
var frontCameraInput: AVCaptureDeviceInput?
var photoOutput: AVCapturePhotoOutput?
var rearCamera: AVCaptureDevice?
var rearCameraInput: AVCaptureDeviceInput?
var previewLayer: AVCaptureVideoPreviewLayer?
var flashMode = AVCaptureDevice.FlashMode.off
var photoCaptureCompletionBlock: ((UIImage?, Error?) -> Void)?
}
extension CameraHelper {
func prepare(completionHandler: @escaping (Error?) -> Void) {
func createCaptureSession() {
self.captureSession = AVCaptureSession()
}
func configureCaptureDevices() throws {
let session = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInDualCamera], mediaType: AVMediaType.video, position: .unspecified)
let cameras = session.devices.compactMap { $0 }
guard !cameras.isEmpty else { throw CameraHelperError.noCamerasAvailable }
for camera in cameras {
if camera.position == .front {
self.frontCamera = camera
}
if camera.position == .back {
self.rearCamera = camera
try camera.lockForConfiguration()
camera.focusMode = .continuousAutoFocus
camera.unlockForConfiguration()
}
}
}
func configureDeviceInputs() throws {
guard let captureSession = self.captureSession else { throw CameraHelperError.captureSessionIsMissing }
if let rearCamera = self.rearCamera {
self.rearCameraInput = try AVCaptureDeviceInput(device: rearCamera)
if captureSession.canAddInput(self.rearCameraInput!) { captureSession.addInput(self.rearCameraInput!) }
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 CameraHelperError.inputsAreInvalid }
self.currentCameraPosition = .front
}
else { throw CameraHelperError.noCamerasAvailable }
}
func configurePhotoOutput() throws {
guard let captureSession = self.captureSession else { throw CameraHelperError.captureSessionIsMissing }
self.photoOutput = AVCapturePhotoOutput()
self.photoOutput!.setPreparedPhotoSettingsArray([AVCapturePhotoSettings(format: [AVVideoCodecKey : AVVideoCodecType.jpeg])], completionHandler: nil)
if captureSession.canAddOutput(self.photoOutput!) { captureSession.addOutput(self.photoOutput!) }
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 CameraHelperError.captureSessionIsMissing }
self.previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
self.previewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
self.previewLayer?.connection?.videoOrientation = .portrait
view.layer.insertSublayer(self.previewLayer!, at: 0)
self.previewLayer?.frame = view.frame
}
func switchCameras() throws {
guard let currentCameraPosition = currentCameraPosition, let captureSession = self.captureSession, captureSession.isRunning else { throw CameraHelperError.captureSessionIsMissing }
captureSession.beginConfiguration()
func switchToFrontCamera() throws {
guard let rearCameraInput = self.rearCameraInput, captureSession.inputs.contains(rearCameraInput),
let frontCamera = self.frontCamera else { throw CameraHelperError.invalidOperation }
self.frontCameraInput = try AVCaptureDeviceInput(device: frontCamera)
captureSession.removeInput(rearCameraInput)
if captureSession.canAddInput(self.frontCameraInput!) {
captureSession.addInput(self.frontCameraInput!)
self.currentCameraPosition = .front
}
else {
throw CameraHelperError.invalidOperation
}
}
func switchToRearCamera() throws {
guard let frontCameraInput = self.frontCameraInput, captureSession.inputs.contains(frontCameraInput),
let rearCamera = self.rearCamera else { throw CameraHelperError.invalidOperation }
self.rearCameraInput = try AVCaptureDeviceInput(device: rearCamera)
captureSession.removeInput(frontCameraInput)
if captureSession.canAddInput(self.rearCameraInput!) {
captureSession.addInput(self.rearCameraInput!)
self.currentCameraPosition = .rear
}
else { throw CameraHelperError.invalidOperation }
}
switch currentCameraPosition {
case .front:
try switchToRearCamera()
case .rear:
try switchToFrontCamera()
}
captureSession.commitConfiguration()
}
func captureImage(completion: @escaping (UIImage?, Error?) -> Void) {
guard let captureSession = captureSession, captureSession.isRunning else { completion(nil, CameraHelperError.captureSessionIsMissing); return }
let settings = AVCapturePhotoSettings()
settings.flashMode = self.flashMode
self.photoOutput?.capturePhoto(with: settings, delegate: self)
self.photoCaptureCompletionBlock = completion
}
}
extension CameraHelper: AVCapturePhotoCaptureDelegate {
public func photoOutput(_ captureOutput: AVCapturePhotoOutput, didFinishProcessingPhoto photoSampleBuffer: CMSampleBuffer?, previewPhoto previewPhotoSampleBuffer: CMSampleBuffer?,
resolvedSettings: AVCaptureResolvedPhotoSettings, bracketSettings: AVCaptureBracketedStillImageSettings?, error: Swift.Error?) {
if let error = error { self.photoCaptureCompletionBlock?(nil, error) }
else if let buffer = photoSampleBuffer, let data = AVCapturePhotoOutput.jpegPhotoDataRepresentation(forJPEGSampleBuffer: buffer, previewPhotoSampleBuffer: nil),
let image = UIImage(data: data) {
self.photoCaptureCompletionBlock?(image, nil)
}
else {
self.photoCaptureCompletionBlock?(nil, CameraHelperError.unknown)
}
}
}
extension CameraHelper {
enum CameraHelperError: Swift.Error {
case captureSessionAlreadyRunning
case captureSessionIsMissing
case inputsAreInvalid
case invalidOperation
case noCamerasAvailable
case unknown
}
public enum CameraPosition {
case front
case rear
}
}
这是帮助程序类.
推荐答案
使用 .builtInWideAngleCamera 代替 .builtInDualCamera 来设置AVCaptureDevice.
Use .builtInWideAngleCamera instead of .builtInDualCamera for Setup AVCaptureDevice.
在您的项目上替换此功能
Replace this function on your Project
func configureCaptureDevices() throws {
let session = AVCaptureDevice.DiscoverySession(deviceTypes: [. builtInWideAngleCamera], mediaType: AVMediaType.video, position: .unspecified)
let cameras = session.devices.compactMap { $0 }
guard !cameras.isEmpty else { throw CameraHelperError.noCamerasAvailable }
for camera in cameras {
if camera.position == .front {
self.frontCamera = camera
}
if camera.position == .back {
self.rearCamera = camera
try camera.lockForConfiguration()
camera.focusMode = .continuousAutoFocus
camera.unlockForConfiguration()
}
}
}
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