iPhone: Real-time video color info, focal length, aperture?

Is there any way using AVFoundat开发者_如何学Goion and CoreVideo to get color info, aperture and focal length values in real-time?

Let me explain. Say when I am shooting video I want to sample the color in a small portion of the screen and output that in RGB values to the screen? Also, I would like to show what the current aperture is set at.

Does anyone know if it is possible to gather these values? Currently I have only seen that this is possible with still images.

Ideas?

AVCaptureStillImageOutput will get you a real time still from the video stream, including exif data for focal length, aperture, etc. Color info you could calculate yourself from that bitmap.

AVFoundation, CoreVideo, and CoreMedia include support for getting a video bitmap in "real-time". From there you can process a portion of the RGB pixels however you want.

I don't know of any current public iOS API to get you the aperture.

The focal length is fixed, but differs between product models. ifixit.com might have that info.

You can get the aperture by:- camera.lensAperture this will give the aperture of the camera of iPhone whichever you selected