Error: "Fatal signal 11 (SIGSEGV), code 1" when passing Mat object from java to jni function

Issue

I am running the video camera using the OpenCV function. I pass the Mat object to the jni function it works for awhile, them the error:

10-10 13:03:17.978: A/libc(28693): Fatal signal 11 (SIGSEGV), code 1, fault addr 0x9 in tid 28791 (Thread-5418)

Java code that runs the camera and calls the jni function:

package com.adhamenaya;

import java.util.ArrayList;

import org.opencv.android.BaseLoaderCallback;
import org.opencv.android.CameraBridgeViewBase;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewFrame;
import org.opencv.android.CameraBridgeViewBase.CvCameraViewListener2;
import org.opencv.android.LoaderCallbackInterface;
import org.opencv.android.OpenCVLoader;
import org.opencv.core.Mat;
//import org.opencv.highgui.Highgui;
import org.opencv.imgproc.Imgproc;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnTouchListener;
import android.view.WindowManager;

public class MainActivity extends Activity implements CvCameraViewListener2,
        OnTouchListener {

    private static final String TAG = "OCVSample::Activity";
    private Mat mRgba;
    private Mat mGray;
    private CameraBridgeViewBase mOpenCvCameraView;

    private ArrayList<Mat> mats = new ArrayList<Mat>();

    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();
                mOpenCvCameraView.setOnTouchListener(MainActivity.this);

            }
                break;
            default: {
                super.onManagerConnected(status);
            }
                break;
            }
        }
    };

    public MainActivity() {
        Log.i(TAG, "Instantiated new " + this.getClass());
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Log.i(TAG, "called onCreate");
        super.onCreate(savedInstanceState);

        Native.loadlibs();


        mOpenCvCameraView = (CameraBridgeViewBase) findViewById(R.id.cam_view);
        mOpenCvCameraView.setVisibility(SurfaceView.VISIBLE);
        mOpenCvCameraView.setCvCameraViewListener(this);

        Native.setup(mFaceCascadeFile, mNoseCascadeFile, mLandmarks);
    }

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

    @Override
    public void onResume() {
        super.onResume();
        OpenCVLoader.initAsync(OpenCVLoader.OPENCV_VERSION_2_4_3, this,
                mLoaderCallback);
    }

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

    public void onCameraViewStarted(int width, int height) {
        mGray = new Mat();
        mRgba = new Mat();
    }

    public void onCameraViewStopped() {
    }

    public Mat onCameraFrame(CvCameraViewFrame inputFrame) {
        mRgba = inputFrame.rgba();
        Imgproc.cvtColor(mRgba, mGray, Imgproc.COLOR_BGRA2GRAY);
        Native.runJni(mFaceCascadeFile, mNoseCascadeFile, mLandmarks,
                mRgba.getNativeObjAddr());

        return mRgba;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        // TODO Auto-generated method stub
        return false;
    }


}

Jni function:

JNIEXPORT jbyteArray JNICALL Java_com_adhamenaya_Native_runJni(JNIEnv * env,
        jobject obj, jstring faceCascadeFile, jstring noseCascadeFile,
        jstring landmarks, jlong frame) {

    cv::Mat& inFrame = *(cv::Mat*) frame;

    if (!gsys.loadFaceCascade(faceCascadeFnameStr)) {
        LOG("Could not load face cascade");
        gsys.loadFaceCascade(faceCascadeFnameStr);
    } else {
        LOG("Face cascade: OK");

    }

    if (!gsys.loadNoseCascade(noseCascadeFnameStr)) {
        LOG("Could not load nose cascade");
        gsys.loadNoseCascade(noseCascadeFnameStr);

    } else {
        LOG("Nose cascade: OK");

    }

    gsys.setFrameRate(30);
    gsys.setProgramState(DETECT);

    clock_t tin, tout = 0;

    cv::flip(inFrame, inFrame, 0);
    cv::transpose(inFrame, inFrame);

    dlib::shape_predictor pose_model;
    dlib::deserialize(landmarksStr) >> pose_model;


     gsys.setCurrentFrame(inFrame);

     tin = clock();
     trigger_hr(gsys, faces, pose_model);

     // Process the frame
     size_t spm;
     float motionStrengthX, motionStrengthY;
     float phiYaw = -0xFFFFFFFF, thetaPitch = -0xFFFFFFFF;

     if (faces.size()) {
     faces[0].getSpm(gsys, spm, motionStrengthX, motionStrengthY);
     faces[0].getFacePose(phiYaw, thetaPitch);
     }

     tout = tout + clock() - tin;
     if ((gsys.getFrameCount() % 30) == 29) {
     double secs_between_frames = (double) (tout) / (CLOCKS_PER_SEC * 30.0f);
     printf("FPS = %2.2f\n", 1.0f / secs_between_frames);
     LOG("FPS = %2.2f ", 1.0f / secs_between_frames);
     tout = 0;
     }

     char spmText[100];

     //sprintf(spmText,
     //     "SPM = %zu, P = %2.2f, T = %2.2f, MS-X = %2.2f, MS-Y = %2.2f", spm,
     //     phiYaw, thetaPitch, motionStrengthX, motionStrengthY);

     LOG("SPM = %zu, P = %2.2f, T = %2.2f, MS-X = %2.2f, MS-Y = %2.2f", spm,
     phiYaw, thetaPitch, motionStrengthX, motionStrengthY);

    std::string str;
    str = "SPM=";

    jbyteArray arr = env->NewByteArray(str.length());
    env->SetByteArrayRegion(arr, 0, str.length(), (jbyte*) str.c_str());

    return arr;

}

Kindly help me.

Solution

After two days of searching online, I could figure out that the problem is because of the 'Memory leak', and this happens when I am reading the frames from a video and send them the jni function, without releasing frames after finishing working on them, so always I will have the frames in the memory.

What I did is to move the Mat object in the C++ code outside the scope of the function and make it a class scope object, so it will not create a new object each time the function is called.

Also, I called:

inFrame.release();

to free the memory after finishing working on it.

Answered By - Adham Enaya