适用于 IOS 的摄像机本机扩展

Posted 2023-02-23

【中文标题】适用于 IOS 的摄像机本机扩展

【英文标题】：Video Camera native extension for IOS

【发布时间】：2013-02-13 11:25:16

【问题描述】：

我正在为 ios 构建一个原生扩展，我想在其中实现条码扫描器。

我已经按照AVCam 的示例进行了操作，并在本机应用程序（完整的 xcode）中进行了尝试，它工作正常。

现在，我想在 Flex 移动项目中使用此代码。我已经能够创建 ANE 并将其放在 Flex Mobile 项目中，并且可以调用 ANE 的功能。

它似乎工作正常，但我的问题是我无法通过摄像头看到您所看到的内容。我的意思是，我有一个方法可以调用来启动相机并初始化捕获。我还实现了 captureOutput 委托，最奇怪的是，当我运行我的应用程序时，我可以看到 initcapture 和 captureOutput 中的日志，就像应用程序正在捕获数据一样，但在 iPad 中我看不到相机。

这是我使用的代码的一部分：

- (void)initCapture

    NSLog(@"camera view capture init");
    /*We setup the input*/
    self.device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    AVCaptureDeviceInput *captureInput = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];
    /*We setupt the output*/
    captureOutput = [[AVCaptureVideoDataOutput alloc] init];
    // If the queue is blocked when new frames are captured, those frames will be automatically dropped
    captureOutput.alwaysDiscardsLateVideoFrames = YES;
    //captureOutput.minFrameDuration = CMTimeMake(1, 10); Uncomment it to specify a minimum duration for each video frame
    [captureOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
    // Set the video output to store frame in BGRA (It is supposed to be faster)

    NSString* key = (NSString*)kCVPixelBufferPixelFormatTypeKey;
    // Set the video output to store frame in 422YpCbCr8(It is supposed to be faster)

    //************************Note this line
    NSNumber* value = [NSNumber numberWithUnsignedInt:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange];

    NSDictionary* videoSettings = [NSDictionary dictionaryWithObject:value forKey:key];
    [captureOutput setVideoSettings:videoSettings];

    //And we create a capture session
    self.captureSession = [[AVCaptureSession alloc] init];
    //We add input and output
    [self.captureSession addInput:captureInput];
    [self.captureSession addOutput:captureOutput];


    if ([self.captureSession canSetSessionPreset:AVCaptureSessionPreset1280x720])
    
        NSLog(@"camera view Set preview port to 1280X720");
        self.captureSession.sessionPreset = AVCaptureSessionPreset1280x720;
     else
        //set to 640x480 if 1280x720 not supported on device
        if ([self.captureSession canSetSessionPreset:AVCaptureSessionPreset640x480])
        
            NSLog(@"camera view Set preview port to 640X480");
            self.captureSession.sessionPreset = AVCaptureSessionPreset640x480;
        


    /*We add the preview layer*/

    self.prevLayer = [AVCaptureVideoPreviewLayer layerWithSession: self.captureSession];

    if ([self.prevLayer respondsToSelector:@selector(connection)])
        self.prevLayer.connection.videoOrientation = AVCaptureVideoOrientationLandscapeLeft;
    else
        self.prevLayer.orientation = AVCaptureVideoOrientationLandscapeLeft;

    self.prevLayer.frame = CGRectMake(150, 0, 700, 700);
    self.prevLayer.videoGravity = AVLayerVideoGravityResizeAspect;
    [self.view.layer addSublayer: self.prevLayer];


- (void) startScanning 
    NSLog(@"camera view start scanning");
    self.state = LAUNCHING_CAMERA;
    [self.captureSession startRunning];
    self.prevLayer.hidden = NO;
    self.state = CAMERA;


#pragma mark AVCaptureSession delegate

- (void)captureOutput:(AVCaptureOutput *)captureOutput
didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer
       fromConnection:(AVCaptureConnection *)connection

    NSLog(@"camera view Capture output");

我应该如何解决这个问题？

非常感谢。

【参考方案1】：

我想我已经解决了。

代替：

[self.view.layer addSublayer: self.prevLayer];

我说：

UIViewController *mainController = [UIApplication sharedApplication].keyWindow.rootViewController;
[mainController.view.layer addSublayer: self.prevLayer];

现在，我可以在我的 flex 应用程序上看到相机了。