我可以使用 AVFoundation 实现的自定义相机的缩放功能(1 倍以上)。在 iPhone X 机型之前这一切都很好。但我想在 iPhone 11 和 iPhone 11 Pro 设备中实现 0.5 倍变焦。
我编写的代码无法将其设置为 0.5 倍缩放。我已经尝试了所有可能的
[.builtInTripleCamera, .builtInDualWideCamera, .builtInUltraWideCamera]
组合。设备类型为 .builtinUltraWideCamera
的捕获设备未为 minAvailableVideoZoomFactor
提供 0.5。
在 iPhone 11 上进行测试时,我还从
[.builtInDualCamera, .builtInTelephotoCamera, .builtInWideAngleCamera, .builtInTrueDepthCamera]
中删除了 deviceTypes
。
感谢任何解决此问题的帮助。下面是适用于 1 倍变焦以上的代码。
/// Called from -handlePinchGesture
private func zoom(_ scale: CGFloat) {
let captureDevice = cameraDevice(.back)
do {
try captureDevice?.lockForConfiguration()
var minZoomFactor: CGFloat = captureDevice?.minAvailableVideoZoomFactor ?? 1.0
let maxZoomFactor: CGFloat = captureDevice?.maxAvailableVideoZoomFactor ?? 1.0
if #available(iOS 13.0, *) {
if captureDevice?.deviceType == .builtInDualWideCamera || captureDevice?.deviceType == .builtInTripleCamera || captureDevice?.deviceType == .builtInUltraWideCamera {
minZoomFactor = 0.5
}
}
zoomScale = max(minZoomFactor, min(beginZoomScale * scale, maxZoomFactor))
captureDevice?.videoZoomFactor = zoomScale
captureDevice?.unlockForConfiguration()
} catch {
print("ERROR: locking configuration")
}
}
@objc private func handlePinchGesture(_ recognizer: UIPinchGestureRecognizer) {
var allTouchesOnPreviewLayer = true
let numTouch = recognizer.numberOfTouches
for i in 0 ..< numTouch {
let location = recognizer.location(ofTouch: i, in: view)
let convertedTouch = previewLayer.convert(location, from: previewLayer.superlayer)
if !previewLayer.contains(convertedTouch) {
allTouchesOnPreviewLayer = false
break
}
}
if allTouchesOnPreviewLayer {
zoom(recognizer.scale)
}
}
func cameraDevice(_ position: AVCaptureDevice.Position) -> AVCaptureDevice? {
var deviceTypes = [AVCaptureDevice.DeviceType]()
deviceTypes.append(contentsOf: [.builtInDualCamera, .builtInTelephotoCamera, .builtInWideAngleCamera, .builtInTrueDepthCamera])
if #available(iOS 13.0, *) {
deviceTypes.append(contentsOf: [.builtInTripleCamera, .builtInDualWideCamera, .builtInUltraWideCamera])
}
let availableCameraDevices = AVCaptureDevice.DiscoverySession(deviceTypes: deviceTypes, mediaType: .video, position: position).devices
guard availableCameraDevices.isEmpty == false else {
debugPrint("ERROR: No camera devices found!!!")
return nil
}
for device in availableCameraDevices {
if device.position == position {
return device
}
}
guard let defaultDevice = AVCaptureDevice.default(for: AVMediaType.video) else {
debugPrint("ERROR: Can't initialize default back camera!!!")
return nil
}
return defaultDevice
}
根据 Apple Docs,AVCaptureDevice 的最小“zoomFactor”属性不能小于 1.0。这有点令人困惑,因为根据您选择的相机,变焦系数 1 将是不同的视场或光学视角。默认的 iPhone 相机应用程序显示一个标签,上面写着“0.5”,但这只是超广角镜头相对于标准相机变焦系数的标签。
您已经从设备获取了 minZoomFactor(可能为 1),因此您应该使用您正在读取的设备的最小值和最大值来设置输入到“captureDevice.videoZoomFactor”中的因子的范围。然后,当您选择超广角镜头时,将变焦系数设置为 1 将是您所能到达的最广角! (相对于标准镜头视野的 0.5 倍)。
针对希望将光学变焦级别设置为 0.5 倍的用户进行更新
礼貌:https://github.com/NextLevel/NextLevel/issues/187
public class func primaryVideoDevice(forPosition position: AVCaptureDevice.Position) -> AVCaptureDevice? {
// -- Changes begun
if #available(iOS 13.0, *) {
let hasUltraWideCamera: Bool = true // Set this variable to true if your device is one of the following - iPhone 11, iPhone 11 Pro, & iPhone 11 Pro Max
if hasUltraWideCamera {
// Your iPhone has UltraWideCamera.
let deviceTypes: [AVCaptureDevice.DeviceType] = [AVCaptureDevice.DeviceType.builtInUltraWideCamera]
let discoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: deviceTypes, mediaType: AVMediaType.video, position: position)
return discoverySession.devices.first
}
}
// -- Changes end
var deviceTypes: [AVCaptureDevice.DeviceType] = [AVCaptureDevice.DeviceType.builtInWideAngleCamera] // builtInWideAngleCamera // builtInUltraWideCamera
if #available(iOS 11.0, *) {
deviceTypes.append(.builtInDualCamera)
} else {
deviceTypes.append(.builtInDuoCamera)
}
// prioritize duo camera systems before wide angle
let discoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: deviceTypes, mediaType: AVMediaType.video, position: position)
for device in discoverySession.devices {
if #available(iOS 11.0, *) {
if (device.deviceType == AVCaptureDevice.DeviceType.builtInDualCamera) {
return device
}
} else {
if (device.deviceType == AVCaptureDevice.DeviceType.builtInDuoCamera) {
return device
}
}
}
return discoverySession.devices.first
}
问题是,当您尝试从
discoverySession.devices
获取某种类型的设备时,它会返回不支持您所需的超宽设备的 default 设备。
我的 iPhone 12Pro Max 就是这种情况,仅返回一台设备用于后置位置,报告类型
BuiltInWideAngleCamera
,但这只是碱液,它是中间摄像头,不是广角,不是长焦。不知道为什么苹果开发人员这样做,看起来像一个过时的遗留架构。
解决方案并不明显:使用
AVCaptureDevice.default(.builtInTripleCamera, for: .video, position: .back)
使真实设备能够从 1(逻辑上的 0.5)缩放。
我们不能将缩放系数设置为小于 1。
我通过使用“.builtInDualWideCamera”解决了这个问题。
在本例中,我们使用“超广角相机”,其变焦系数为 2.0(默认值)等于“广角相机”上的正常变焦系数。 (最小值为 1.0)
如果您的iPhone不支持“.builtInDualWideCamera”,我们将照常使用“.builtInWideAngleCamera”,缩放系数为1.0(最小值)
func getCameraDevices() -> [AVCaptureDevice] {
var deviceTypes = [AVCaptureDevice.DeviceType]()
if #available(iOS 13.0, *) {
deviceTypes.append(contentsOf: [.builtInDualWideCamera])
self.isUltraWideCamera = true
self.defaultZoomFactor = 2.0
}
if(deviceTypes.isEmpty){
deviceTypes.append(contentsOf: [.builtInWideAngleCamera])
self.isUltraWideCamera = false
self.defaultZoomFactor = 1.0
}
return AVCaptureDevice.DiscoverySession(deviceTypes: deviceTypes, mediaType: .video, position: .unspecified).devices
}
我终于在这里找到了答案:https://stackoverflow.com/a/48524598。 使用超广角摄像头设备并调用
-[AVCaptureSession setSessionPreset:AVCaptureSessionPresetPhoto]
解决了该问题,显示与照片应用程序相同的裁剪。