Android - OnPreviewFrame not called

Question

This is my cameraPreview I have set the listener in SurfaceChanged. I can see the camera inside the app - yet the OnPreviewFrame is never called. Here is most of the code

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private static boolean DEBUGGING = true;
    private static final String LOG_TAG = "CameraPreviewSample";
    private static final String CAMERA_PARAM_ORIENTATION = "orientation";
    private static final String CAMERA_PARAM_LANDSCAPE = "landscape";
    private static final String CAMERA_PARAM_PORTRAIT = "portrait";
    protected Activity mActivity;
    private SurfaceHolder mHolder;
    protected Camera mCamera;
    protected List<Camera.Size> mPreviewSizeList;
    protected List<Camera.Size> mPictureSizeList;
    protected Camera.Size mPreviewSize;
    protected Camera.Size mPictureSize;
    private int mSurfaceChangedCallDepth = 0;
    private int mCameraId;
    private LayoutMode mLayoutMode;
    private int mCenterPosX = -1;
    private int mCenterPosY;
    public Mat frame1=null;
    public Mat frame2=null;
    PreviewReadyCallback mPreviewReadyCallback = null;
    //////Alon
    public static int SENSITIVITY_VALUE = 20;
    public static int BLUR_SIZE = 10;

    public Rect objectBoundingRectangle = new Rect(0, 0, 0, 0);

    double ballAverage = 131.5;
    int frameCounter = 0;

    public static enum LayoutMode {
        FitToParent, // Scale to the size that no side is larger than the parent
        NoBlank // Scale to the size that no side is smaller than the parent
    };

    public interface PreviewReadyCallback {
        public void onPreviewReady();
    }

    /**
     * State flag: true when surface's layout size is set and surfaceChanged()
     * process has not been completed.
     */
    protected boolean mSurfaceConfiguring = false;

    public CameraPreview(Activity activity, int cameraId, LayoutMode mode) {
        super(activity); // Always necessary
        mActivity = activity;
        mLayoutMode = mode;
        mHolder = getHolder();
        mHolder.addCallback(this);
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
            if (Camera.getNumberOfCameras() > cameraId) {
                mCameraId = cameraId;
            } else {
                mCameraId = 0;
            }
        } else {
            mCameraId = 0;
        }

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
            mCamera = Camera.open(mCameraId);
        } else {
            mCamera = Camera.open();
        }
        Camera.Parameters cameraParams = mCamera.getParameters();
        mPreviewSizeList = cameraParams.getSupportedPreviewSizes();
        mPictureSizeList = cameraParams.getSupportedPictureSizes();

    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        try {
            mCamera.setPreviewDisplay(mHolder);
        } catch (IOException e) {
            mCamera.release();
            mCamera = null;
        }
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
        mSurfaceChangedCallDepth++;
        doSurfaceChanged(width, height);
        mSurfaceChangedCallDepth--;
    }

    private void doSurfaceChanged(int width, int height) {
        mCamera.stopPreview();

        Camera.Parameters cameraParams = mCamera.getParameters();
        boolean portrait = isPortrait();

        // The code in this if-statement is prevented from executed again when surfaceChanged is
        // called again due to the change of the layout size in this if-statement.
        if (!mSurfaceConfiguring) {
            Camera.Size previewSize = determinePreviewSize(portrait, width, height);
            Camera.Size pictureSize = determinePictureSize(previewSize);
            if (DEBUGGING) { Log.v(LOG_TAG, "Desired Preview Size - w: " + width + ", h: " + height); }
            mPreviewSize = previewSize;
            mPictureSize = pictureSize;
            mSurfaceConfiguring = adjustSurfaceLayoutSize(previewSize, portrait, width, height);
            // Continue executing this method if this method is called recursively.
            // Recursive call of surfaceChanged is very special case, which is a path from
            // the catch clause at the end of this method.
            // The later part of this method should be executed as well in the recursive
            // invocation of this method, because the layout change made in this recursive
            // call will not trigger another invocation of this method.
            if (mSurfaceConfiguring && (mSurfaceChangedCallDepth <= 1)) {
                return;
            }
        }

        configureCameraParameters(cameraParams, portrait);
        mSurfaceConfiguring = false;

        try {
            mCamera.startPreview();
        } catch (Exception e) {
            Log.w(LOG_TAG, "Failed to start preview: " + e.getMessage());

            // Remove failed size
            mPreviewSizeList.remove(mPreviewSize);
            mPreviewSize = null;

            // Reconfigure
            if (mPreviewSizeList.size() > 0) { // prevent infinite loop
                surfaceChanged(null, 0, width, height);
            } else {
                Toast.makeText(mActivity, "Can't start preview", Toast.LENGTH_LONG).show();
                Log.w(LOG_TAG, "Gave up starting preview");
            }
        }

        if (null != mPreviewReadyCallback) {
            mPreviewReadyCallback.onPreviewReady();
        }



        //////////////////////////Alon
        if (mCamera == null) {
            return;
        }



        mCamera.setPreviewCallback(new PreviewCallback() {

            @Override
            public void onPreviewFrame(byte[] data, Camera camera) {

                Mat frame = Byte_to_Mat(data);
                if(frame1==null) {
                    frame1 = frame;
                }
                else
                {
                    if (frame2 == null)
                    {
                        frame2 = frame;
                    }
                    else
                    {
                        frame1 = frame2;
                        frame2 = frame;
                    }
                    detectBall(frame1,frame2);
                }

            }
        });
    }
    public Mat Byte_to_Mat(byte[] data) {

        Mat jpegData = new Mat(1, data.length, CvType.CV_8UC1);
        jpegData.put(0, 0, data);
        return jpegData;
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        stop();
    }

    public void stop() {
        if (null == mCamera) {
            return;
        }
        mCamera.stopPreview();
        mCamera.release();
        mCamera = null;
    }

    public boolean isPortrait() {
        return (mActivity.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT);
    }

    public void setOneShotPreviewCallback(PreviewCallback callback) {
        if (null == mCamera) {
            return;
        }
        mCamera.setOneShotPreviewCallback(callback);
    }

    public void setPreviewCallback(PreviewCallback callback) {
        if (null == mCamera) {
            return;
        }
        mCamera.setPreviewCallback(callback);
    }

    public Camera.Size getPreviewSize() {
        return mPreviewSize;
    }

    public void setOnPreviewReady(PreviewReadyCallback cb) {
        mPreviewReadyCallback = cb;
    }

I have tried setting the setPreviewCallback in the constructor too. And also on Surface Created. Does someone know the source of this?