如何使用 AVCaptureDeviceDiscoverySession 获取前置摄像头、后置摄像头和音频

Question

在 iOS 10 出来之前，我使用以下代码为我的录像机获取视频和音频捕获：

 for device in AVCaptureDevice.devices()
 {
     if (device as AnyObject).hasMediaType( AVMediaTypeAudio )
     {
         self.audioCapture = device as? AVCaptureDevice
     }
     else if (device as AnyObject).hasMediaType( AVMediaTypeVideo )
     {
         if (device as AnyObject).position == AVCaptureDevicePosition.back
         {
             self.backCameraVideoCapture = device as? AVCaptureDevice
         }
         else
         {
             self.frontCameraVideoCapture = device as? AVCaptureDevice
         }
     }
 }

当iOS 10终于出来的时候，我在运行我的代码中收到了以下警告。请注意，我的录像机在大约 2 周内仍能正常工作。

'devices()' was deprecated in iOS 10.0: Use AVCaptureDeviceDiscoverySession instead.

因为我今天早上运行我的代码，所以我的录像机停止工作了。 xCode8 没有给我任何错误，但相机捕获的 previewLayer 是完全白色的。当我开始录制时，我收到以下错误：

Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo={NSLocalizedDescription=The operation could not be completed, NSUnderlyingError=0x17554440 {Error Domain=NSOSStatusErrorDomain Code=-12780 "(null)"}, NSLocalizedFailureReason=An unknown error occurred (-12780)}

我认为这与我使用的是已弃用的方法有关 AVCaptureDevice.devices()。因此，我想知道如何使用 AVCaptureDeviceDiscoverySession 来代替？

提前感谢您的帮助！

Answer 1

您可以通过以下方式获取前置摄像头：

AVCaptureDevice.default(.builtInWideAngleCamera, for: AVMediaType.video, position: .front)

后置摄像头：

AVCaptureDevice.default(.builtInWideAngleCamera, for: AVMediaType.video, position: .back)

还有麦克风：

AVCaptureDevice.default(.builtInMicrophone, for: AVMediaType.audio, position: .unspecified)

Answer 2

对于我的视频捕获应用程序，我使用以下代码获取麦克风、前置和后置摄像头，并且我已经从 iOS 7 到 10.0.2 测试了此代码。

        var frontCamera : AVCaptureDevice?
        var rearCamera : AVCaptureDevice?

        captureSession = AVCaptureSession()

        let devices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeVideo)

        let audioDevices = AVCaptureDevice.devicesWithMediaType(AVMediaTypeAudio)

        for mic in audioDevices {
            audioDevice = mic as? AVCaptureDevice
            audioCapturePossible = true
        }

        for device in devices {
            if device.position == AVCaptureDevicePosition.Front {
                frontCamera = device as? AVCaptureDevice
                hasFrontCamera = true
            }
            else if device.position == AVCaptureDevicePosition.Back {
                rearCamera = device as? AVCaptureDevice
                hasRearCamera = true
            }

        }

Answer 3

这是我获取相机位置的代码 (Swift 3) :

// Find a camera with the specified AVCaptureDevicePosition, returning nil if one is not found
func cameraWithPosition(_ position: AVCaptureDevicePosition) -> AVCaptureDevice?
{
    if let deviceDescoverySession = AVCaptureDeviceDiscoverySession.init(deviceTypes: [AVCaptureDeviceType.builtInWideAngleCamera],
                                                          mediaType: AVMediaTypeVideo,
                                                          position: AVCaptureDevicePosition.unspecified) {

        for device in deviceDescoverySession.devices {
            if device.position == position {
                return device
            }
        }
    }

    return nil
}

如果需要，您还可以通过更改 deviceTypes 数组从 iPhone 7+（双摄像头）获取新的 devicesTypes。

这是一本好书：https://forums.developer.apple.com/thread/63347

Answer 4

尝试以下代码获取相机 ID：

NSString *cameraID = nil;

NSArray *captureDeviceType = @[AVCaptureDeviceTypeBuiltInWideAngleCamera];
AVCaptureDeviceDiscoverySession *captureDevice = 
              [AVCaptureDeviceDiscoverySession 
                discoverySessionWithDeviceTypes:captureDeviceType 
                mediaType:AVMediaTypeVideo 
                position:AVCaptureDevicePositionUnspecified];

cameraID = [captureDevice.devices.lastObject localizedName];

Answer 5

Swift 3

用于选择后置摄像头：（也可以根据需要更改.back）

要选择另一个设备类型，只需将其添加到 [ ] 内（即：

[deviceTypeCamera, AVCaptureDeviceType.builtInMicrophone]

（或者像我在代码中用后置摄像头做的那样创建一个私人出租屋）

 private let position = AVCaptureDevicePosition.back
 private let deviceTypeBackCamera = AVCaptureDeviceType.builtInWideAngleCamera

 private func selectCaptureDevice() -> AVCaptureDevice? {
    return AVCaptureDeviceDiscoverySession(deviceTypes: [deviceTypeBackCamera], mediaType: AVMediaTypeVideo, position: position).devices.first

 }

Answer 6

Swift 4, iOS 10+ 和 Xcode 10.1 替换

if let cameraID = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .front)?.localizedName {
       //cameraID = "Front Camera"
}

AVCaptureDevice.DiscoverySession实施

if let cameraID = AVCaptureDevice.DiscoverySession.init(deviceTypes: [AVCaptureDevice.DeviceType.builtInWideAngleCamera], mediaType: .video, position: .front).devices.first?.localizedName{
        //cameraID = "Front Camera"
}

需要用#available(iOS 10,*) check.

包裹起来

Answer 7

适用于 Xcode 9.2 和 Swift 4

AVCaptureDevice.default(.builtInWideAngleCamera, for: AVMediaType.video, position: .back)

https://developer.apple.com/documentation/avfoundation/avcapturedevice/2361508-default

Answer 8

示例：iOS11Swift4

override func viewDidLoad() {
    super.viewDidLoad()

    // Get the back-facing camera for capturing videos

    // AVCaptureDevice.default(.builtInWideAngleCamera, for: AVMediaType.video, position: .back)
    let deviceDiscoverySession = AVCaptureDevice.default(.builtInWideAngleCamera, for: AVMediaType.video, position: .back)

   guard let captureDevice = deviceDiscoverySession else {
       print("Failed to get the camera device")
       return
   }

    do {
        // Get an instance of the AVCaptureDeviceInput class using the previous device object.
        let input = try AVCaptureDeviceInput(device: captureDevice)

        // Set the input device on the capture session.
        captureSession.addInput(input)

    } catch {
        // If any error occurs, simply print it out and don't continue any more.
        print(error)
        return
    }

    // Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
    videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
    videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
    videoPreviewLayer?.frame = view.layer.bounds
    view.layer.addSublayer(videoPreviewLayer!)

    // Start video capture.
    captureSession.startRunning()

Answer 9

Swift 4 (xCode 10.1)

这就是 Swift 最新版本中对我有用的东西。我没有看到这个答案，我花了一段时间才弄清楚，所以这里是如何获得前置摄像头。

 if let device = AVCaptureDevice.defaultDevice(withDeviceType: .builtInWideAngleCamera , mediaType: AVMediaTypeVideo, position: .front)  {
    //Do the camera thing here..
}

Answer 10

05/2019 :

 //video
        self.session = AVCaptureSession()
        guard
            let videoDeviceInput = try? AVCaptureDeviceInput(device: device!),
            self.session!.canAddInput(videoDeviceInput)
            else { return }
        self.session!.addInput(videoDeviceInput)

  //audio
        guard
            let audioDeviceInput = try? AVCaptureDeviceInput(device: mic!),
            self.session!.canAddInput(audioDeviceInput)
            else { return }
        self.session!.addInput(audioDeviceInput)

Answer 11

简体：

func getCamera(with position: AVCaptureDevice.Position) -> AVCaptureDevice? {
    let deviceDescoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInDualCamera], mediaType: .video, position: .unspecified)
    return deviceDescoverySession.devices.first(where: { [=10=].position == position })
}

// and you can use like that:

guard let device = getCamera(with: .back) else { return }

Answer 12

在Swift 5更容易

AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera], mediaType: AVMediaType.video, position: .front)

如何使用 AVCaptureDeviceDiscoverySession 获取前置摄像头、后置摄像头和音频

How to get front camera, back camera and audio with AVCaptureDeviceDiscoverySession

avfoundation

ios

avcapturedevice

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