iOS present camera overlay view

gistfile1.m

//create an overlay view instance
OverlayView *overlay = [[OverlayView alloc]
        initWithFrame:CGRectMake(0, 0, SCREEN_WIDTH, SCREEN_HEIGTH)];

//create a new image picker instance
UIImagePickerController *picker =
                [[UIImagePickerController alloc] init];
//set source to video!
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
//hide all controls
picker.showsCameraControls = NO;
picker.navigationBarHidden = YES;
picker.toolbarHidden = YES;
//make the video preview full size
picker.wantsFullScreenLayout = YES;
picker.cameraViewTransform =
CGAffineTransformScale(picker.cameraViewTransform,
            CAMERA_TRANSFORM_X,
            CAMERA_TRANSFORM_Y);
//set our custom overlay view
picker.cameraOverlayView = overlay;

//show picker
[self presentModalViewController:picker animated:YES];