How do I detect when the flash for the AVCaptureDevice has finished and still image capture has begun?

Question

I am making a pretty simple/standard camera app that uses a AVCaptureVideoPreviewLayer. When the user presses a button, I call captureStillImageAsynchronouslyFromConnection on the AVCaptureStillImageOutput to capture an image. At the time that I capture the image, I animate a simple white UIView over the preview layer as an indication to the user that a photo is being captured, and hide it again after the image capture is complete.

My problem is that when the camera flash is on, I don't want to display the white view immediately because the photo capture doesn't actually happen until after the flash has gone off. Is there a way to determine that the flash has finished or that the image capture has actually begun? Perhaps via KVO, NSNotificationCenter, or something?

Answer 1

Try using KVO on the capturingStillImage property of AVCaptureStillImageOutput.

The documentation reads like that may be what you need.