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

Question

在iOS 10问世之前,我使用以下代码来获取录像机的视频和音频:

 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终于问世时,我在运行代码时收到了以下警告.请注意,我的录像机仍然可以正常工作约2周.

在iOS 10.0中不推荐使用'devices()':请改用AVCaptureDeviceDiscoverySession.

当我今天早上运行我的代码时,我的录像机停止了工作.xCode8没有给我任何错误,但摄像头捕获的previewLayer是完全白色的.当我开始录制时,我收到以下错误:

错误域= AVFoundationErrorDomain代码= -11800"操作无法完成"UserInfo = {NSLocalizedDescription =操作无法完成,NSUnderlyingError = 0x17554440 {错误域= NSOSStatusErrorDomain代码= -12780"(null)"},NSLocalizedFailureReason = An发生未知错误(-12780)}

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

提前谢谢你的帮助!

Answer 1

您可以使用以下内容获得前置摄像头:

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

后置摄像头:

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

麦克风:

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

Answer 2

Swift 4,iOS 10+和Xcode 10.1取代

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

使用AVCaptureDevice.DiscoverySession实现

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,*)检查来包装它.

Answer 3

这是我的代码(Swift 3)来获取相机位置:

// 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.

这是一个很好的阅读:https://forums.developer.apple.com/thread/63347

Answer 4

它适用于Xcode 9.2和Swift 4

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

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