VideoCapture OpenCV无法打开Android

Question

我正在尝试使用Java在Android Studio中打开VideoCapture，但出于某种原因，每当我运行videoCapture.isOpened（）时，我都被告知VideoCapture未被打开。我无法弄清楚为什么这可能是我可以做什么或我可以做什么来打开VideoCapture时我问。我的代码是：

public class SecondActivity extends Activity
{
private static final String TAG = "SecondActivity";

static
{
    if(!OpenCVLoader.initDebug())
    {
        Log.d(TAG, "OpenCV not loaded");
    }
    else
    {
        Log.d(TAG, "OpenCV loaded");


    }
}

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_second);

}

public void videoClicked(View view)
{
    VideoCapture videoCapture = new VideoCapture();
    videoCapture.open(CameraBridgeViewBase.CAMERA_ID_FRONT);
    if(videoCapture.isOpened()) Log.i(TAG, "Opened!");
    else Log.i(TAG, "Not opened");
}
}

我有一个更复杂的活动，它显示屏幕上摄像机的信号，所以我知道摄像机正在工作，但我不明白为什么VideoCapture无法工作。该活动的代码如下，您可以看到我在那里尝试打开视频捕获的位置。

public class MainActivity extends Activity implements CameraBridgeViewBase.CvCameraViewListener2
{
private static final String TAG = "MainActivity";
private CameraBridgeViewBase mOpenCvCameraView;
private static HashMap<String, Integer> images = new HashMap<String, Integer>();
private BackgroundSubtractorMOG2 bgSub = new BackgroundSubtractorMOG2(30, 4, false);
private VideoCapture videoCapture;
private Size mPreviewSize;
private Mat mCurrentFrame, mFilteredFrame, mInRangeResult, mCurrentFrameHsv;
private ConcurrentLinkedQueue<Bitmap> mResultBitmaps = new ConcurrentLinkedQueue<Bitmap>();
public static final int RESULT_MATRIX_BUFFER_SIZE = 3;

static
{
    if(!OpenCVLoader.initDebug())
    {
        Log.d(TAG, "OpenCV not loaded");
    }
    else
    {
        Log.d(TAG, "OpenCV loaded");


    }
}

@Override
protected void onCreate(Bundle savedInstanceState)
{
    Log.i(TAG, "On Create");
    super.onCreate(savedInstanceState);
    getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
    setContentView(R.layout.activity_main);
    mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.HelloOpenCvView);
    mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
    mOpenCvCameraView.setCvCameraViewListener(this);
}

//Edits the pixels of the image in image view to highlight certain colors
public void editPixelsClicked(View view)
{
    OpenCVManager manager = new OpenCVManager();
    ImageView imageView = (ImageView) findViewById(R.id.greenImage);
    Bitmap bmp = manager.editPixels(this, imageView, R.mipmap.colorfulimage);
    imageView.setImageBitmap(bmp);
}

public void captureClicked(View view)
{
    mOpenCvCameraView.disableView();
    setupCamera(0);
    if(videoCapture.grab()) Log.i(TAG, "Grabbed");
    else Log.i(TAG, "Failed to grab");
    Intent intent = new Intent(this, SecondActivity.class);
    startActivity(intent);
}

public void setupCamera(int cameraID)
{
    if(videoCapture != null)
    {
        VideoCapture camera = videoCapture;
        videoCapture = null;
        camera.release();
    }

    videoCapture = new VideoCapture();
    Log.i(TAG, "Recreated video capture");

    videoCapture.open(1);
    if(videoCapture.isOpened()) Log.i(TAG, "Video capture opened");
    else Log.i(TAG, "Video capture failed to open");
    /*List<Size> previewSizes = videoCapture.getSupportedPreviewSizes();
    double largestPreviewSize = 1280 * 720; // We should be smaller than this...
    double smallestWidth = 480; // Let's not get a smaller width than this...
    for (Size previewSize : previewSizes) {
        if (previewSize.area() < largestPreviewSize && previewSize.width >= smallestWidth) {
            mPreviewSize = previewSize;
        }
    }*/

    videoCapture.set(Highgui.CV_CAP_PROP_FRAME_WIDTH, 500);
    videoCapture.set(Highgui.CV_CAP_PROP_FRAME_HEIGHT, 300);
}

private void initMatrices() {
    mCurrentFrame = new Mat();
    mCurrentFrameHsv = new Mat();
    mFilteredFrame = new Mat();
    mInRangeResult = new Mat();

    // Since drawing to screen occurs on a different thread than the processing,
    // we use a queue to handle the bitmaps we will draw to screen
    mResultBitmaps.clear();
    for (int i = 0; i < RESULT_MATRIX_BUFFER_SIZE; i++) {
        Bitmap resultBitmap = Bitmap.createBitmap((int) mPreviewSize.width, (int) mPreviewSize.height,
                Bitmap.Config.ARGB_8888);
        mResultBitmaps.offer(resultBitmap);
    }
}

@Override
public void onPause()
{
    super.onPause();
    if(mOpenCvCameraView != null)
    {
        mOpenCvCameraView.disableView();
    }
}

public void onDestroy()
{
    super.onDestroy();
    if(mOpenCvCameraView != null)
    {
        mOpenCvCameraView.disableView();
    }
}

public void onCameraViewStarted(int width, int height)
{
    Mat mat = new Mat(2,2, CvType.CV_8UC3, new Scalar(0,0,255));
}

public void onCameraViewStopped()
{

}

public Mat onCameraFrame(CameraBridgeViewBase.CvCameraViewFrame inputFrame)
{
    return inputFrame.rgba();
}

private BaseLoaderCallback mLoaderCallback =  new BaseLoaderCallback(this) {
    @Override
    public void onManagerConnected(int status)
    {
        switch(status)
        {
            case LoaderCallbackInterface.SUCCESS:
            {
                Log.i(TAG, "OpenCV loaded successfully");
                mOpenCvCameraView.enableView();
            } break;
            default:
            {
                super.onManagerConnected(status);
            } break;
        }
    }
};

@Override
public void onResume()
{
    super.onResume();
    OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_11, this, mLoaderCallback);
}
}