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I am using AVFoundation to capture still images from camera (capturing still images and not video frame) using captureStillImageAsynchronouslyFromConnection. This gives to me a buffer of type CMSSampleBuffer, which I am calling imageDataSampleBuffer.

As far as I have understood, this buffer can contain any type of data related to media, and the type of data is determined when I am configuring the output settings.

for output settings, I make a dictionary with value: AVVideoCodecJPEG for key: AVVideoCOdecKey.

There is no other codec option. But when I read the AVFoundation Programming Guide>Media Capture, I can see that 420f, 420v, BGRA, jpeg are the available encoded formats supported for iPhone 3gs (which i am using)

I want to get the yuv420 (i.e. 420v) formatted image data into the imageSampleBuffer. Is that possible?

if I print the availableImageDataCodecTypes, I get only JPEG if I print availableImageDataCVPixelFormatTypes, I get three numbers 875704422, 875704438, 1111970369.

Is it possible that these three numbers map to 420f, 420v, BGRA?

If yes, which key should I modify in my output settings? I tried putting the value: [NSNumber numberWithInt:875704438] for key: (id)kCVPixelBufferPixelFormatTypeKey. Would it work?

If yes, how do I extract this data from the imageSampleBuffer?

Also, In which format is UIImage stored? Can it be any format? Is it just NSData with some extra info which makes it interpreted as an image?

neeraj
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1 Answers1

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I have been trying to use this method :

Raw image data from camera like "645 PRO"

I am saving the data using writeToFile and I have been trying to open it using irfan view.

But I am unable to verify whether or not the saved file is in yuv format ot not because irfan view gives error that it is unable to read the headers.

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neeraj
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