iPhone AVFoundation camera orientation

Question

I\'ve been tearing my hair out trying to get the AVFoundation camera to capture a picture in the correct orientation (i.e. the device orientation) but I can\'t get it to wor

Answer 1

Well, it's taken me fracking forever but I've done it!

The bit of code I was looking for is

[UIDevice currentDevice].orientation;

This goes in as so

AVCaptureConnection *videoConnection = [CameraVC connectionWithMediaType:AVMediaTypeVideo fromConnections:[imageCaptureOutput connections]];
if ([videoConnection isVideoOrientationSupported])
{
    [videoConnection setVideoOrientation:[UIDevice currentDevice].orientation];
}

And it works perfectly :D

Woop woop!

Answer 2

How to use with AVCaptureFileOutput ?

- (void)detectVideoOrientation:(AVCaptureFileOutput *)captureOutput {
    for(int i = 0; i < [[captureOutput connections] count]; i++) {
        AVCaptureConnection *captureConnection = [[captureOutput connections] objectAtIndex:i];
        if([captureConnection isVideoOrientationSupported]) {
            [captureConnection setVideoOrientation:[[UIDevice currentDevice] orientation]];
        }
    }
}

Answer 3

The following is from AVCam, I added too it:

- (void)deviceOrientationDidChange{

    UIDeviceOrientation deviceOrientation = [[UIDevice currentDevice] orientation];

    AVCaptureVideoOrientation newOrientation;

    if (deviceOrientation == UIDeviceOrientationPortrait){
        NSLog(@"deviceOrientationDidChange - Portrait");
        newOrientation = AVCaptureVideoOrientationPortrait;
    }
    else if (deviceOrientation == UIDeviceOrientationPortraitUpsideDown){
        NSLog(@"deviceOrientationDidChange - UpsideDown");
        newOrientation = AVCaptureVideoOrientationPortraitUpsideDown;
    }

    // AVCapture and UIDevice have opposite meanings for landscape left and right (AVCapture orientation is the same as UIInterfaceOrientation)
    else if (deviceOrientation == UIDeviceOrientationLandscapeLeft){
        NSLog(@"deviceOrientationDidChange - LandscapeLeft");
        newOrientation = AVCaptureVideoOrientationLandscapeRight;
    }
    else if (deviceOrientation == UIDeviceOrientationLandscapeRight){
        NSLog(@"deviceOrientationDidChange - LandscapeRight");
        newOrientation = AVCaptureVideoOrientationLandscapeLeft;
    }

    else if (deviceOrientation == UIDeviceOrientationUnknown){
        NSLog(@"deviceOrientationDidChange - Unknown ");
        newOrientation = AVCaptureVideoOrientationPortrait;
    }

    else{
        NSLog(@"deviceOrientationDidChange - Face Up or Down");
        newOrientation = AVCaptureVideoOrientationPortrait;
    }

    [self setOrientation:newOrientation];
}

And be sure to add this to your init method:

NSNotificationCenter *notificationCenter = [NSNotificationCenter defaultCenter];
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[notificationCenter addObserver:self
    selector:@selector(deviceOrientationDidChange) 
    name:UIDeviceOrientationDidChangeNotification object:nil];
[self setOrientation:AVCaptureVideoOrientationPortrait];

Answer 4

This uses the view controller's orientation method. This works for me, hopefully works for you.

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
    [super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];

    AVCaptureConnection *videoConnection = self.prevLayer.connection;
    [videoConnection setVideoOrientation:(AVCaptureVideoOrientation)toInterfaceOrientation];
}

Answer 5

Isn't this a little cleaner?

    AVCaptureVideoOrientation newOrientation;
    switch ([[UIDevice currentDevice] orientation]) {
    case UIDeviceOrientationPortrait:
        newOrientation = AVCaptureVideoOrientationPortrait;
        break;
    case UIDeviceOrientationPortraitUpsideDown:
        newOrientation = AVCaptureVideoOrientationPortraitUpsideDown;
        break;
    case UIDeviceOrientationLandscapeLeft:
        newOrientation = AVCaptureVideoOrientationLandscapeRight;
        break;
    case UIDeviceOrientationLandscapeRight:
        newOrientation = AVCaptureVideoOrientationLandscapeLeft;
        break;
    default:
        newOrientation = AVCaptureVideoOrientationPortrait;
    }
    [stillConnection setVideoOrientation: newOrientation];

Answer 6

I am writing this code in Swift in case may be needful for someone.

Step-1: Generate Orientation notifications (in yourviewDidLoad)

    UIDevice.currentDevice().beginGeneratingDeviceOrientationNotifications()
NSNotificationCenter.defaultCenter().addObserver(self, selector: Selector("deviceOrientationDidChange:"), name: UIDeviceOrientationDidChangeNotification, object: nil)

Step-2: Take picture. Here we will interchange orientation of videoConnection. In AVFoundation there is a minor change in orientation especially for landscape orientation. So we will just interchange it. For example we will change from LandscapeRight to LandscapeLeft and viceversa

  func takePicture() {
if let videoConnection = stillImageOutput!.connectionWithMediaType(AVMediaTypeVideo) {

    var newOrientation: AVCaptureVideoOrientation?
    switch (UIDevice.currentDevice().orientation) {
    case .Portrait:
        newOrientation = .Portrait
        break
    case .PortraitUpsideDown:
        newOrientation = .PortraitUpsideDown
        break
    case .LandscapeLeft:
        newOrientation = .LandscapeRight
        break
    case .LandscapeRight:
        newOrientation = .LandscapeLeft
        break
    default :
        newOrientation = .Portrait
        break

    }
    videoConnection.videoOrientation = newOrientation!


  stillImageOutput!.captureStillImageAsynchronouslyFromConnection(videoConnection) {
    (imageDataSampleBuffer, error) -> Void in

    let imageData = AVCaptureStillImageOutput.jpegStillImageNSDataRepresentation(imageDataSampleBuffer)

    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_BACKGROUND, 0)) {

      dispatch_async(dispatch_get_main_queue()) {

        let image = UIImage(data: imageData!)!
        let portraitImage = image.fixOrientation()


      }
    }


  }
}

  }

NOTE: Please notice the new orientation value for Landscape orientations. Its just the opposite. (This is the culprit ::UHHHH)

Step-3: Fix orientation (UIImage extension)

extension UIImage {

func fixOrientation() -> UIImage {

    if imageOrientation == UIImageOrientation.Up {
        return self
    }

    var transform: CGAffineTransform = CGAffineTransformIdentity

    switch imageOrientation {
    case UIImageOrientation.Down, UIImageOrientation.DownMirrored:
        transform = CGAffineTransformTranslate(transform, size.width, size.height)
        transform = CGAffineTransformRotate(transform, CGFloat(M_PI))
        break
    case UIImageOrientation.Left, UIImageOrientation.LeftMirrored:
        transform = CGAffineTransformTranslate(transform, size.width, 0)
        transform = CGAffineTransformRotate(transform, CGFloat(M_PI_2))
        break
    case UIImageOrientation.Right, UIImageOrientation.RightMirrored:
        transform = CGAffineTransformTranslate(transform, 0, size.height)
        transform = CGAffineTransformRotate(transform, CGFloat(-M_PI_2))
        break
    case UIImageOrientation.Up, UIImageOrientation.UpMirrored:
        break
    }

    switch imageOrientation {
    case UIImageOrientation.UpMirrored, UIImageOrientation.DownMirrored:
        CGAffineTransformTranslate(transform, size.width, 0)
        CGAffineTransformScale(transform, -1, 1)
        break
    case UIImageOrientation.LeftMirrored, UIImageOrientation.RightMirrored:
        CGAffineTransformTranslate(transform, size.height, 0)
        CGAffineTransformScale(transform, -1, 1)
    case UIImageOrientation.Up, UIImageOrientation.Down, UIImageOrientation.Left, UIImageOrientation.Right:
        break
    }

    let ctx: CGContextRef = CGBitmapContextCreate(nil, Int(size.width), Int(size.height), CGImageGetBitsPerComponent(CGImage), 0, CGImageGetColorSpace(CGImage), CGImageAlphaInfo.PremultipliedLast.rawValue)!

    CGContextConcatCTM(ctx, transform)

    switch imageOrientation {
    case UIImageOrientation.Left, UIImageOrientation.LeftMirrored, UIImageOrientation.Right, UIImageOrientation.RightMirrored:
        CGContextDrawImage(ctx, CGRectMake(0, 0, size.height, size.width), CGImage)
        break
    default:
        CGContextDrawImage(ctx, CGRectMake(0, 0, size.width, size.height), CGImage)
        break
    }

    let cgImage: CGImageRef = CGBitmapContextCreateImage(ctx)!

    return UIImage(CGImage: cgImage)
}


   }