How can I get Camera Calibration Data on iOS? aka AVCameraCalibrationData

Question

As I understand it, AVCameraCalibrationData is only available over AVCaptureDepthDataOutput. Is that correct?

AVCaptureDepthDataOutput on the other hand is only acce

Answer 1

Here is a more complete/updated code example in swift 5 that is put together from previous answers. This gets you the camera intrinsics matrix for an iphone.

based on:

• https://stackoverflow.com/a/48159895/67166
• https://stackoverflow.com/a/48565639/6716

// session setup
captureSession = AVCaptureSession()

let captureVideoDataOutput = AVCaptureVideoDataOutput()

captureSession?.addOutput(captureVideoDataOutput)

// enable the flag
if #available(iOS 11.0, *) {
    captureVideoDataOutput.connection(with: .video)?.isCameraIntrinsicMatrixDeliveryEnabled = true
} else {
    // ...
}

// `isCameraIntrinsicMatrixDeliveryEnabled` should be set before this
captureSession?.startRunning()

and now inside AVCaptureVideoDataOutputSampleBufferDelegate.captureOutput(...)

if #available(iOS 11.0, *) {
    if let camData = CMGetAttachment(sampleBuffer, key:kCMSampleBufferAttachmentKey_CameraIntrinsicMatrix, attachmentModeOut:nil) as? Data {
        let matrix: matrix_float3x3 = camData.withUnsafeBytes { $0.pointee }
        print(matrix)
        // > simd_float3x3(columns: (SIMD3(1599.8231, 0.0, 0.0), SIMD3(0.0, 1599.8231, 0.0), SIMD3(539.5, 959.5, 1.0)))
    }
} else {
    // ...
}