具有多个方向问题的AVCaptureSession [英] AVCaptureSession with multiple orientations issue

问题描述

我正在尝试实施条形码扫描仪。我有一个AVCaptureSession从AVCaptureDevice接收视频。我想支持所有方向。使用以下代码，当我运行应用程序时，纵向方向的一切都很好。但是在横向方向上，视图会旋转但视频输入不会旋转。所以我最终得到了90度旋转视频。

I am attempting to implement a barcode scanner. I have an AVCaptureSession that takes in video from AVCaptureDevice. I want to support all orientations. With the following code, when I run the app, everything is fine in the portrait orientation. However in landscape orientation, the view rotates but the video input does not. So I end up with a 90degree rotated video.

当我实现 - （NSUInteger）supportedInterfaceOrientations方法时，一切都被锁定到纵向位置。

When I implement -(NSUInteger)supportedInterfaceOrientations method, then everything gets locked to the portrait position.

谁能告诉我如何解决这个问题？

Can anyone tell me how I can fix this issue?

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    [self setupCaptureSession];

    _previewLayer.frame = _previewView.bounds;
    _previewView.center = self.view.center;
    _previewView.backgroundColor = [UIColor redColor];
    [_previewView.layer addSublayer:_previewLayer];

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationWillEnterForeground:) name:UIApplicationWillEnterForegroundNotification object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(applicationDidEnterBackground:) name:UIApplicationDidEnterBackgroundNotification object:nil];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    [self startRunning];
}

-(void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    [self stopRunning];
}

-(void) setupCaptureSession
{
    if (_captureSession)
        return;

    _videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    if (!_videoDevice)
    {
        NSLog(@"No video camera on this device");
        return;
    }

    _captureSession = [[AVCaptureSession alloc]init];

    _videoInput = [[AVCaptureDeviceInput alloc]initWithDevice:_videoDevice error:nil];

    if ([_captureSession canAddInput:_videoInput])
    {
        [_captureSession addInput:_videoInput];
    }

    _previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];

    _previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;

}

-(void) startRunning
{
    if (_running)
        return;

    [_captureSession startRunning];
    _running = YES;
}

- (void) stopRunning
{
    if (!_running)
        return;

    [_captureSession stopRunning];
    _running = NO;
}

/*
-(NSUInteger)supportedInterfaceOrientations
{
    return UIInterfaceOrientationLandscapeLeft|UIInterfaceOrientationLandscapeRight|UIInterfaceOrientationPortrait|UIInterfaceOrientationPortraitUpsideDown;
}

*/

编辑：

我尝试了以下代码，但previewLayer方向仍然是颠倒/横向。

I tried the following code but the previewLayer orientation is still upsidedown/sideways.

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(orientationChanged)
                                                 name:UIDeviceOrientationDidChangeNotification
                                               object:nil];
-(void) orientationChanged
{
    if (self.interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown)
        [_previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationPortraitUpsideDown];

    if (self.interfaceOrientation == UIInterfaceOrientationPortrait)
        [_previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationPortrait];

    if (self.interfaceOrientation == UIInterfaceOrientationLandscapeLeft)
        [_previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeLeft];

    if (self.interfaceOrientation == UIInterfaceOrientationLandscapeRight)
        [_previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeRight];
}

推荐答案

用以下内容修复它

-(void) orientationChanged {
    UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
    if (deviceOrientation == UIInterfaceOrientationPortraitUpsideDown)
        [_previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationPortraitUpsideDown];

    else if (deviceOrientation == UIInterfaceOrientationPortrait)
        [_previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationPortrait];

    else if (deviceOrientation == UIInterfaceOrientationLandscapeLeft)
        [_previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeLeft];

    else
        [_previewLayer.connection setVideoOrientation:AVCaptureVideoOrientationLandscapeRight];
}

这篇关于具有多个方向问题的AVCaptureSession的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！