Opencv Camera

import org.opencv.android.Utils;
import org.opencv.core.Core;
import org.opencv.core.Mat;
import org.opencv.highgui.Highgui;
import org.opencv.highgui.VideoCapture;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class CameraViewOpenCV extends SurfaceView implements SurfaceHolder.Callback, Runnable {
    private static final String TAG = "Sample::SurfaceView";

    private SurfaceHolder       mHolder;
    private VideoCapture        mCamera;
    private Mat mRgba;

    public CameraViewOpenCV(Context context) {
        super(context);
        mHolder = getHolder();
        mHolder.addCallback(this);
    }

    public void surfaceChanged(SurfaceHolder _holder, int format, int width, int height) {
        Log.i(TAG, "surfaceCreated");

        if (mCamera != null && mCamera.isOpened()) {
            mCamera.set(Highgui.CV_CAP_PROP_FRAME_WIDTH, 640);
            mCamera.set(Highgui.CV_CAP_PROP_FRAME_HEIGHT, 480);
        }
    }

    public void surfaceCreated(SurfaceHolder holder) {
        Log.i(TAG, "surfaceCreated");

        mRgba  = new Mat();
        mCamera = new VideoCapture(Highgui.CV_CAP_ANDROID);
        if(mCamera.isOpened()){
            (new Thread(this)).start();
        } else {
            mRgba.release();
            mCamera.release();
            mCamera = null;
            Log.e(TAG, "Failed to open native camera");
        }


    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        Log.i(TAG, "surfaceDestroyed");
        if (mCamera != null) {
            mCamera.release();
            mCamera = null;
        }
    }

    public double timet(double l){
        return ((Core.getTickCount() - l)/Core.getTickFrequency()) * 1000;
    }

    public void run() {
        int i = 0;
        double d, total = 0;
        while (true) {
            d = Core.getTickCount();
            Bitmap bmp = null;

            if (mCamera == null)
                break;
            if (!mCamera.grab()) {
                Log.e(TAG, "mCamera.grab() failed");
                break;
            }

            mCamera.retrieve(mRgba, Highgui.CV_CAP_ANDROID_COLOR_FRAME_RGBA);
            bmp = Bitmap.createBitmap(mRgba.cols(), mRgba.rows(), Bitmap.Config.ARGB_8888);
            Utils.matToBitmap(mRgba, bmp);

            if (bmp != null) {
                Canvas canvas = mHolder.lockCanvas();
                if (canvas != null) {
                    canvas.drawBitmap(bmp, (canvas.getWidth() - bmp.getWidth()) / 2, (canvas.getHeight() - bmp.getHeight()) / 2, null);
                    mHolder.unlockCanvasAndPost(canvas);
                }
                bmp.recycle();

                // measure frame rate
                total += timet(d);
                if((i++ % 100) == 0){
                    Log.w("Opencv Camera", "Average frame time: " + total/100 + "ms" + " ##Frame Rate:" + (100000/(total)) + "fps");
                    total = 0;
                }
            }
        }
    }
}