ios - GPUImage2 , 前后摄像头切换

Question

如何使用 swift(使用按钮切换)在 GPUImage2(切换版本)中旋转或切换前后摄像头。任何帮助将不胜感激。提前致谢。

Answer 1

让我们考虑 GPUImage2 的主要示例:

do {
    camera = try Camera(sessionPreset:AVCaptureSessionPreset640x480)
    filter = SaturationAdjustment()
    camera --> filter --> renderView
    camera.startCapture()
} catch {
    fatalError("Could not initialize rendering pipeline: \(error)")
}

一旦你的相机开始拍摄，你可以通过这种方式从后到前切换:

do {

    // Stop the capture of the current camera and remove its targets
    sharedImageProcessingContext.runOperationSynchronously{
        camera.stopCapture()
        camera.removeAllTargets()
    }

    // Build a new Camera object, using the back or front physical camera
    if camera.location == .frontFacing {
        camera = try Camera(sessionPreset:.vga640x480, location:.backFacing)
    } else {
        camear = try Camera(sessionPreset:.vga640x480, location:.frontFacing)
    }

    //Rebuild the pipeline
    camera --> filter --> renderView
    camera.startCapture()

} catch {
    print("Error switching camera : \(error)")
}

旁注#1:使用的默认相机是后置相机，正如 Camera.init() 的默认值所暗示的那样:

public init(sessionPreset:AVCaptureSession.Preset, 
             cameraDevice:AVCaptureDevice? = nil, 
                 location:PhysicalCameraLocation = .backFacing, 
...

旁注#2:Camera 对象呈现 location 属性。不幸的是，它的 didSet 访问器仍在“TODO”中:

public var location:PhysicalCameraLocation {
    didSet {
        // TODO: Swap the camera locations, framebuffers as needed
    }
}