iPhone AVFoundation摄像头方向-Java 学习之路

我一直在试图让AVFoundation相机以正确的方向（即设备方向）拍摄照片，但我无法让它工作 .

我看过教程，我看过WWDC演示文稿，我已经下载了WWDC示例程序，但即便如此也没有 .

我的应用程序的代码是......

AVCaptureConnection *videoConnection = [CameraVC connectionWithMediaType:AVMediaTypeVideo fromConnections:[imageCaptureOutput connections]];
if ([videoConnection isVideoOrientationSupported])
{
    [videoConnection setVideoOrientation:[UIApplication sharedApplication].statusBarOrientation];
}

[imageCaptureOutput captureStillImageAsynchronouslyFromConnection:videoConnection
                                                completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error)
{
    if (imageDataSampleBuffer != NULL)
    {
        //NSLog(@"%d", screenOrientation);

        //CMSetAttachment(imageDataSampleBuffer, kCGImagePropertyOrientation, [NSString stringWithFormat:@"%d", screenOrientation], 0);

        NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
        UIImage *image = [[UIImage alloc] initWithData:imageData];

        [self processImage:image];
    }
}];

（processImage使用与WWDC代码相同的writeImage ...方法）

并且WWDC应用程序的代码是......

AVCaptureConnection *videoConnection = [AVCamDemoCaptureManager connectionWithMediaType:AVMediaTypeVideo fromConnections:[[self stillImageOutput] connections]];
        if ([videoConnection isVideoOrientationSupported]) {
            [videoConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];
        }

[[self stillImageOutput] captureStillImageAsynchronouslyFromConnection:videoConnection
                                                             completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
                                                                 if (imageDataSampleBuffer != NULL) {
                                                                     NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
                                                                     UIImage *image = [[UIImage alloc] initWithData:imageData];                                                                 
                                                                     ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
                                                                     [library writeImageToSavedPhotosAlbum:[image CGImage]
                                                                                               orientation:(ALAssetOrientation)[image imageOrientation]
                                                                                           completionBlock:^(NSURL *assetURL, NSError *error){
                                                                                               if (error) {
                                                                                                   id delegate = [self delegate];
                                                                                                   if ([delegate respondsToSelector:@selector(captureStillImageFailedWithError:)]) {
                                                                                                       [delegate captureStillImageFailedWithError:error];
                                                                                                   }                                                                                               
                                                                                               }
                                                                                           }];
                                                                     [library release];
                                                                     [image release];
                                                                 } else if (error) {
                                                                     id delegate = [self delegate];
                                                                     if ([delegate respondsToSelector:@selector(captureStillImageFailedWithError:)]) {
                                                                         [delegate captureStillImageFailedWithError:error];
                                                                     }
                                                                 }
                                                             }];

在他们的代码的开头，他们将AVOrientation设置为肖像，这似乎很奇怪，但我试图让它检测设备的当前方向并使用它 .

正如您所看到的，我已经将[UIApplication sharedApplication] statusBarOrientation设置为尝试获取此功能，但它仍然只能以纵向保存照片 .

任何人都可以就我需要做的事情提供任何帮助或建议吗？

谢谢！

奥利弗

11 回答

嗯，这是我永远的水力压裂，但我已经做到了！

我正在寻找的代码是

[UIDevice currentDevice].orientation;

这是如此

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

它完美无缺：D

Woop woop！

回复于 2024-04-29T23:52:50+08:00

这不是更干净吗？

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];

回复于 2024-04-29T23:52:50+08:00

以下是来自AVCam，我也补充说：

- (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];
}

并确保将此添加到您的init方法：

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

回复于 2024-04-29T23:52:50+08:00

0
有两件事需要注意

a）正如Brian King所写 - LandscapeRight和LandscapeLeft在枚举中交换 . 请参阅AVCamCaptureManager示例：
```
// AVCapture and UIDevice have opposite meanings for landscape left and right (AVCapture orientation is the same as UIInterfaceOrientation)
else if (deviceOrientation == UIDeviceOrientationLandscapeLeft)
    orientation = AVCaptureVideoOrientationLandscapeRight;
else if (deviceOrientation == UIDeviceOrientationLandscapeRight)
    orientation = AVCaptureVideoOrientationLandscapeLeft;
```
b）还有 UIDeviceOrientationFaceUp 和 UIDeviceOrientationFaceDown 状态，如果您尝试设置为视频方向，则视频将无法录制 . 确保在调用 [UIDevice currentDevice].orientation 时不使用它们！
回复于 2024-04-29T23:52:50+08:00
2
如果您正在使用AVCaptureVideoPreviewLayer，则可以在视图控制器中执行以下操作 .

（假设您有一个名为“previewLayer”的AVCaptureVideoPreviewLayer实例）
```
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
   [self.previewLayer setOrientation:[[UIDevice currentDevice] orientation]];
}
```
回复于 2024-04-29T23:52:50+08:00

我在Swift中编写此代码，以防有人可能需要 .

第1步：生成方向通知（在 viewDidLoad 中）

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

第二步：拍照 . 在这里，我们将互换 videoConnection 的方向 . 在AVFoundation中，方向略有变化，尤其是横向方向 . 所以我们将交换它 . 例如，我们将从 LandscapeRight 更改为 LandscapeLeft ，反之亦然

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()


      }
    }


  }
}

  }

注意：请注意横向方向的新方向值 . 恰恰相反 . （这是罪魁祸首:: UHHHH）

第3步：修复方向（UIImage扩展）

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)
}


   }

回复于 2024-04-29T23:52:50+08:00

-1

这使用视图控制器的方向方法 . 这对我有用，希望对你有用 .

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

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

回复于 2024-04-29T23:52:50+08:00

在Swift中你应该这样做：

videoOutput = AVCaptureVideoDataOutput()
    videoOutput!.setSampleBufferDelegate(self, queue: dispatch_queue_create("sample buffer delegate", DISPATCH_QUEUE_SERIAL))

    if captureSession!.canAddOutput(self.videoOutput) {
        captureSession!.addOutput(self.videoOutput)
    }

    videoOutput!.connectionWithMediaType(AVMediaTypeVideo).videoOrientation = AVCaptureVideoOrientation.PortraitUpsideDown

它对我来说很完美！

回复于 2024-04-29T23:52:50+08:00

4
您还可以创建中间CIImage，并获取属性字典
```
NSDictionary *propDict = [aCIImage properties];
NSString *orientString = [propDict objectForKey:kCGImagePropertyOrientation];
```
并相应变换:)

我喜欢在iOS5中访问所有这些图像元数据是多么容易！
回复于 2024-04-29T23:52:50+08:00

启动捕获会话后以及旋转设备时更新预览图层中的方向 .

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    coordinator.animate(alongsideTransition: { [weak self] context in
        if let connection = self?.previewLayer?.connection, connection.isVideoOrientationSupported {
            if let orientation = AVCaptureVideoOrientation(orientation: UIDevice.current.orientation) {
                connection.videoOrientation = orientation
            }
        }
    }, completion: nil)
    super.viewWillTransition(to: size, with: coordinator)
}

extension AVCaptureVideoOrientation {
    init?(orientation: UIDeviceOrientation) {
        switch orientation {
        case .landscapeRight: self = .landscapeLeft
        case .landscapeLeft: self = .landscapeRight
        case .portrait: self = .portrait
        case .portraitUpsideDown: self = .portraitUpsideDown
        default: return nil
        }
    }
}

回复于 2024-04-29T23:52:50+08:00

如何使用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]];
        }
    }
}

回复于 2024-04-29T23:52:50+08:00

iPhone AVFoundation摄像头方向

11 回答

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