CvVideoCamera flickering iOS

edit

The CvVideoCamera is causing the camera capture to flicker on iOS devices using OpenCV 3.0 beta. 
The same code was working fine with OpenCV 2.4.9

//ViewController.h

 #import <opencv2/videoio/cap_ios.h> 
 @interface ViewController : UIImageView<CvVideoCameraDelegate>
 @property (nonatomic, strong) CvVideoCamera* videoCamera;

//ViewController.m

self.videoCamera = [[CvVideoCamera alloc] initWithParentView:self];
self.videoCamera.defaultAVCaptureDevicePosition = AVCaptureDevicePositionFront;
self.videoCamera.defaultAVCaptureSessionPreset = AVCaptureSessionPreset640x480;
self.videoCamera.defaultAVCaptureVideoOrientation = AVCaptureVideoOrientationPortrait;
self.videoCamera.defaultFPS = 30;
self.videoCamera.delegate = self;
self.videoCamera.parentView = self;

Any ideas?