AVCaptureVideoPreviewLayer orientation - need land

Question

My app is landscape only. I'm presenting the AVCaptureVideoPreviewLayer like this:

self.previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
[self.previewLayer setBackgroundColor:[[UIColor blackColor] CGColor]];
[self.previewLayer setVideoGravity:AVLayerVideoGravityResizeAspect];                    
NSLog(@"previewView: %@", self.previewView);
CALayer *rootLayer = [self.previewView layer];
[rootLayer setMasksToBounds:YES];
[self.previewLayer setFrame:[rootLayer bounds]];
    NSLog(@"previewlayer: %f, %f, %f, %f", self.previewLayer.frame.origin.x, self.previewLayer.frame.origin.y, self.previewLayer.frame.size.width, self.previewLayer.frame.size.height);
[rootLayer addSublayer:self.previewLayer];
[session startRunning];

self.previewView has a frame of (0,0,568,320), which is correct. self.previewLayer logs a frame of (0,0,568,320), which is theoretically correct. However, the camera display appears as a portrait rectangle in the middle of the landscape screen, and the orientation of the camera preview image is wrong by 90 degrees. What am I doing wrong? I need the camera preview layer to appear in the full screen, in landscape mode, and the image should be orientated correctly.

Answer 1

We can't use

[previewLayerConnection setVideoOrientation:[[UIApplication sharedApplication] statusBarOrientation]]; 

because UIInterfaceOrientation != AVCaptureVideoOrientation

But we can just test values... and this work,with following code.

-(void)viewDidLayoutSubviews {
    [super viewDidLayoutSubviews];

    UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
    switch (orientation) {
        case UIInterfaceOrientationPortrait:
            [_videoPreviewLayer.connection setVideoOrientation:AVCaptureVideoOrientationPortrait];
            break;
        case UIInterfaceOrientationPortraitUpsideDown:
            [_videoPreviewLayer.connection setVideoOrientation:AVCaptureVideoOrientationPortraitUpsideDown];
            break;
        case UIInterfaceOrientationLandscapeLeft:
            [_videoPreviewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeLeft];
            break;
        case UIInterfaceOrientationLandscapeRight:
            [_videoPreviewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeRight];
            break;
    }
}

Answer 2

The default camera orientation is Landscape Left (home button one the left). You need to do two things here:

1- Change the previewLayer frame to:

self.previewLayer.frame=self.view.bounds;

You need to set the preview layer frame to the bounds of the screen so that the frame of the preview layer changes when the screen rotates (you cannot use frame of the root view because that does not change with rotation but the bounds of the root view do). In your example, you are setting the previewlayer frame to a previewView property which I do not see.

2- You need to rotate the preview layer connection with the rotation of the device. Add this code in viewDidAppear:

-(void) viewDidAppear:(BOOL)animated
{
  [super viewDidAppear:YES];

  //Get Preview Layer connection
  AVCaptureConnection *previewLayerConnection=self.previewLayer.connection;

  if ([previewLayerConnection isVideoOrientationSupported])
    [previewLayerConnection setVideoOrientation:[[UIApplication sharedApplication] statusBarOrientation]]; 
}

Hope this solves it.

Full Disclosure: This is a simplified version since you do not care if Landscape right or Landscape left.

Answer 3

As there is a deprecation and conversion warning using the above solution, and setting videoOrientation didn't seem to be working in iOS7, I put checks for orientation in my getter for the AVCaptureVideoPreviewLayer like so:

- (AVCaptureVideoPreviewLayer *) previewLayer
{
    if(!_previewLayer)
    {
        _previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession: self.captureSession];

    [_previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];

    _previewLayer.frame = self.view.bounds; // Assume you want the preview layer to fill the view.

    [_previewLayer setPosition:CGPointMake(0,0)];

    if (UIDeviceOrientationLandscapeLeft == [[UIDevice currentDevice] orientation]) {
        _previewLayer.transform = CATransform3DMakeRotation(-M_PI/2, 0, 0, 1);
    }
    else if (UIDeviceOrientationLandscapeRight == [[UIDevice currentDevice] orientation])
    {
        _previewLayer.transform = CATransform3DMakeRotation(M_PI/2, 0, 0, 1);
    }
}

return _previewLayer;
}

Answer 4

Selected answer working for Swift 4.2 - Xcode 10.0 - iOS 12.0:

var videoPreviewLayer: AVCaptureVideoPreviewLayer?

override func viewDidLayoutSubviews() {
  super.viewDidLayoutSubviews()
  if let previewLayerConnection =  self.videoPreviewLayer?.connection, previewLayerConnection.isVideoOrientationSupported {
    updatePreviewLayer(layer: previewLayerConnection, orientation: UIApplication.shared.statusBarOrientation.videoOrientation)
  }
}

private func updatePreviewLayer(layer: AVCaptureConnection, orientation: AVCaptureVideoOrientation) {
  layer.videoOrientation = orientation
  videoPreviewLayer?.frame = self.view.bounds
}

Don't forget the mapping from UIInterfaceOrientation to AVCaptureVideoOrientation

extension UIInterfaceOrientation {

  public var videoOrientation: AVCaptureVideoOrientation {
    switch self {
    case .portrait:
      return AVCaptureVideoOrientation.portrait
    case .landscapeRight:
      return AVCaptureVideoOrientation.landscapeRight
    case .landscapeLeft:
      return AVCaptureVideoOrientation.landscapeLeft
    case .portraitUpsideDown:
      return AVCaptureVideoOrientation.portraitUpsideDown
    default:
      return AVCaptureVideoOrientation.portrait
    }
  }

}

Answer 5

The only way it worked for me in iOS 8 to 11.1 without any problem is to do this and I should mention that in my case, I loaded my application only in landscape mode but it should work in all orientations.(Btw you can overlay the camera manually via imageview or anything u want this way very easily)

@interface ViewController (){
    AVCaptureVideoPreviewLayer * previewLayer;
    AVCaptureSession* session;
}
@property (weak, nonatomic) IBOutlet UIView *cameraPreviewView;


-(void)viewDidLoad{
    AVCaptureDeviceInput *captureInput = [AVCaptureDeviceInput deviceInputWithDevice:[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo] error:nil];
    if (captureInput) {
        session = [[AVCaptureSession alloc] init];
        [session addInput:captureInput];
    }
    previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
    [previewLayer setBackgroundColor:[[UIColor blackColor] CGColor]];
    [previewLayer setVideoGravity:AVLayerVideoGravityResizeAspect];

    CALayer *rootLayer = [self.cameraPreviewView layer];
    [rootLayer setMasksToBounds:YES];
    [previewLayer setFrame:[self.view bounds]];
    [rootLayer addSublayer:previewLayer];
    [session startRunning];

    //Orientation Code is in viewDidLayoutSubviews method
}
-(void)viewDidLayoutSubviews {
    [super viewDidLayoutSubviews];

    UIInterfaceOrientation orientation = [[UIApplication sharedApplication] statusBarOrientation];
    switch (orientation) {
        case UIInterfaceOrientationPortrait:
            [previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationPortrait];
            break;
        case UIInterfaceOrientationPortraitUpsideDown:
            [previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationPortraitUpsideDown];
            break;
        case UIInterfaceOrientationLandscapeLeft:
            [previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeLeft];
            break;
        case UIInterfaceOrientationLandscapeRight:
            [previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeRight];
            break;
        default:break;
    }
}

Answer 6

Hey Guys thanks for all the answers and feedback on this, I came across this as I am working on a swift app. You can achieve the camera to rotate with your device using this code:

override func shouldAutorotate() -> Bool {
        if your cameraController.previewLayer.connection != nil {
            var currentDevice: UIDevice = UIDevice.currentDevice()
            var orientation: UIDeviceOrientation = currentDevice.orientation

            var previewLayerConnection : AVCaptureConnection = your cameraController.previewLayer.connection

            if (previewLayerConnection.supportsVideoOrientation)
            {
                switch (orientation)
                {
                case .Portrait:
                    previewLayerConnection.videoOrientation = AVCaptureVideoOrientation.Portrait
                    break
                case .LandscapeRight:
                    previewLayerConnection.videoOrientation = AVCaptureVideoOrientation.LandscapeLeft
                    break
                case .LandscapeLeft:
                    previewLayerConnection.videoOrientation = AVCaptureVideoOrientation.LandscapeRight
                    break
                default:
                    previewLayerConnection.videoOrientation = AVCaptureVideoOrientation.Portrait
                    break
                }
            }

        }
        return true
    }

Hope this helps!