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?

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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.

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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.

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