无视频输出和 [MC] 从 public 有效用户设置中读取。 Swift/iOS 11 中的错误
No Video Output and [MC] Reading from public effective user settings. Error in Swift/iOS 11
使用 Xcode 9 Beta iOS 11:
我已按照 walkthrough 了解如何从 AVCaptureSession 中提取帧,但无法显示捕获。虽然我在 info.plist 文件中包含了相机权限,但该应用程序似乎在打开后停止运行,并且出现以下错误:
[App Name] does not have sandbox access for frZQaeyWLUvLjeuEK43hmg and IS NOT appropriately entitled
[MC] System group container for systemgroup.com.apple.configurationprofiles path is /private/var/containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
[MC] Reading from public effective user settings.
这里是FrameExtractor.swift的代码供参考:
import UIKit
import AVFoundation
protocol FrameExtractorDelegate: class {
func captured(image: UIImage)
}
class FrameExtractor: NSObject, AVCaptureVideoDataOutputSampleBufferDelegate {
private let position = AVCaptureDevice.Position.front
private let quality = AVCaptureSession.Preset.medium
private var permissionGranted = false
private let sessionQueue = DispatchQueue(label: "session queue")
private let captureSession = AVCaptureSession()
private let context = CIContext()
weak var delegate: FrameExtractorDelegate?
override init() {
super.init()
checkPermission()
sessionQueue.async { [unowned self] in
self.configureSession()
self.captureSession.startRunning()
}
}
// MARK: AVSession configuration
private func checkPermission() {
switch AVCaptureDevice.authorizationStatus(for: AVMediaType.video) {
case .authorized:
permissionGranted = true
case .notDetermined:
requestPermission()
default:
permissionGranted = false
}
}
private func requestPermission() {
sessionQueue.suspend()
AVCaptureDevice.requestAccess(for: AVMediaType.video) { [unowned self] granted in
self.permissionGranted = granted
self.sessionQueue.resume()
}
}
private func configureSession() {
guard permissionGranted else { return }
captureSession.sessionPreset = quality
guard let captureDevice = selectCaptureDevice() else { return }
guard let captureDeviceInput = try? AVCaptureDeviceInput(device: captureDevice) else { return }
guard captureSession.canAddInput(captureDeviceInput) else { return }
captureSession.addInput(captureDeviceInput)
let videoOutput = AVCaptureVideoDataOutput()
videoOutput.setSampleBufferDelegate(self, queue: DispatchQueue(label: "sample buffer"))
guard captureSession.canAddOutput(videoOutput) else { return }
captureSession.addOutput(videoOutput)
guard let connection = videoOutput.connection(with: AVFoundation.AVMediaType.video) else { return }
guard connection.isVideoOrientationSupported else { return }
guard connection.isVideoMirroringSupported else { return }
connection.videoOrientation = .portrait
connection.isVideoMirrored = position == .front
}
private func selectCaptureDevice() -> AVCaptureDevice? {
return AVCaptureDevice.default(for: AVMediaType.video)
// return AVCaptureDevice.devices().filter {
// ([=12=] as AnyObject).hasMediaType(AVMediaType.video) &&
// ([=12=] as AnyObject).position == position
// }.first
}
// MARK: Sample buffer to UIImage conversion
private func imageFromSampleBuffer(sampleBuffer: CMSampleBuffer) -> UIImage? {
guard let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return nil }
let ciImage = CIImage(cvPixelBuffer: imageBuffer)
guard let cgImage = context.createCGImage(ciImage, from: ciImage.extent) else { return nil }
return UIImage(cgImage: cgImage)
}
// MARK: AVCaptureVideoDataOutputSampleBufferDelegate
func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {
print("Got a Frame!")
guard let uiImage = imageFromSampleBuffer(sampleBuffer: sampleBuffer) else { return }
DispatchQueue.main.async { [unowned self] in
self.delegate?.captured(image: uiImage)
}
}
}
对于ViewController.swift:
import UIKit
class ViewController: UIViewController, FrameExtractorDelegate{
@IBOutlet var imageView: UIImageView!
var frameExtractor: FrameExtractor!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
frameExtractor = FrameExtractor()
frameExtractor.delegate = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func captured(image: UIImage) {
imageView.image = image
}
}`
问题出在 captureOutput 中的另一个函数调用中。这是 iOS 11 中对 AVCaptureVideoDataOutputSampleBufferDelegate 中的 captureOutput 的新函数调用:
func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
guard let uiImage = imageFromSampleBuffer(sampleBuffer: sampleBuffer) else { return }
DispatchQueue.main.async { [unowned self] in
self.delegate?.captured(image: uiImage)
}
}
注意 "didOutput sampleBuffer:" 和 "didOutputSampleBuffer sampleBuffer:"
之间的变化
使用 Xcode 9 Beta iOS 11:
我已按照 walkthrough 了解如何从 AVCaptureSession 中提取帧,但无法显示捕获。虽然我在 info.plist 文件中包含了相机权限,但该应用程序似乎在打开后停止运行,并且出现以下错误:
[App Name] does not have sandbox access for frZQaeyWLUvLjeuEK43hmg and IS NOT appropriately entitled
[MC] System group container for systemgroup.com.apple.configurationprofiles path is /private/var/containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
[MC] Reading from public effective user settings.
这里是FrameExtractor.swift的代码供参考:
import UIKit
import AVFoundation
protocol FrameExtractorDelegate: class {
func captured(image: UIImage)
}
class FrameExtractor: NSObject, AVCaptureVideoDataOutputSampleBufferDelegate {
private let position = AVCaptureDevice.Position.front
private let quality = AVCaptureSession.Preset.medium
private var permissionGranted = false
private let sessionQueue = DispatchQueue(label: "session queue")
private let captureSession = AVCaptureSession()
private let context = CIContext()
weak var delegate: FrameExtractorDelegate?
override init() {
super.init()
checkPermission()
sessionQueue.async { [unowned self] in
self.configureSession()
self.captureSession.startRunning()
}
}
// MARK: AVSession configuration
private func checkPermission() {
switch AVCaptureDevice.authorizationStatus(for: AVMediaType.video) {
case .authorized:
permissionGranted = true
case .notDetermined:
requestPermission()
default:
permissionGranted = false
}
}
private func requestPermission() {
sessionQueue.suspend()
AVCaptureDevice.requestAccess(for: AVMediaType.video) { [unowned self] granted in
self.permissionGranted = granted
self.sessionQueue.resume()
}
}
private func configureSession() {
guard permissionGranted else { return }
captureSession.sessionPreset = quality
guard let captureDevice = selectCaptureDevice() else { return }
guard let captureDeviceInput = try? AVCaptureDeviceInput(device: captureDevice) else { return }
guard captureSession.canAddInput(captureDeviceInput) else { return }
captureSession.addInput(captureDeviceInput)
let videoOutput = AVCaptureVideoDataOutput()
videoOutput.setSampleBufferDelegate(self, queue: DispatchQueue(label: "sample buffer"))
guard captureSession.canAddOutput(videoOutput) else { return }
captureSession.addOutput(videoOutput)
guard let connection = videoOutput.connection(with: AVFoundation.AVMediaType.video) else { return }
guard connection.isVideoOrientationSupported else { return }
guard connection.isVideoMirroringSupported else { return }
connection.videoOrientation = .portrait
connection.isVideoMirrored = position == .front
}
private func selectCaptureDevice() -> AVCaptureDevice? {
return AVCaptureDevice.default(for: AVMediaType.video)
// return AVCaptureDevice.devices().filter {
// ([=12=] as AnyObject).hasMediaType(AVMediaType.video) &&
// ([=12=] as AnyObject).position == position
// }.first
}
// MARK: Sample buffer to UIImage conversion
private func imageFromSampleBuffer(sampleBuffer: CMSampleBuffer) -> UIImage? {
guard let imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return nil }
let ciImage = CIImage(cvPixelBuffer: imageBuffer)
guard let cgImage = context.createCGImage(ciImage, from: ciImage.extent) else { return nil }
return UIImage(cgImage: cgImage)
}
// MARK: AVCaptureVideoDataOutputSampleBufferDelegate
func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputSampleBuffer sampleBuffer: CMSampleBuffer!, from connection: AVCaptureConnection!) {
print("Got a Frame!")
guard let uiImage = imageFromSampleBuffer(sampleBuffer: sampleBuffer) else { return }
DispatchQueue.main.async { [unowned self] in
self.delegate?.captured(image: uiImage)
}
}
}
对于ViewController.swift:
import UIKit
class ViewController: UIViewController, FrameExtractorDelegate{
@IBOutlet var imageView: UIImageView!
var frameExtractor: FrameExtractor!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
frameExtractor = FrameExtractor()
frameExtractor.delegate = self
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func captured(image: UIImage) {
imageView.image = image
}
}`
问题出在 captureOutput 中的另一个函数调用中。这是 iOS 11 中对 AVCaptureVideoDataOutputSampleBufferDelegate 中的 captureOutput 的新函数调用:
func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
guard let uiImage = imageFromSampleBuffer(sampleBuffer: sampleBuffer) else { return }
DispatchQueue.main.async { [unowned self] in
self.delegate?.captured(image: uiImage)
}
}
注意 "didOutput sampleBuffer:" 和 "didOutputSampleBuffer sampleBuffer:"
之间的变化