JavaCV OpencvFrameRecorder问题

Question

我正在运行在Dragonboard 820上运行Android API 23的本机android上，该文件读取/ storage / emulated / 0 /目录中的视频文件。它使用Android的JAVACV库，我手动设置该库以将视频文件读取为Frame对象，然后将其转换为Mat对象。该Mat对象作为参数传递给本机代码，程序在其中获取帧并生成Mat对象的灰度级。本机代码还发送转换是否成功。然后将该灰度Mat对象转换回Frame对象后，使用OpenCVFrameRecorder（）进行记录。此外，我正在使用Async在单独的线程中运行JavaCV代码。代码在下面

import android.os.AsyncTask;  
import android.os.Bundle;  
import android.os.Environment; 
import android.support.v7.app.AppCompatActivity; 
import android.util.Log; 
import android.widget.TextView;

import org.bytedeco.javacpp.opencv_core;  
import org.bytedeco.javacv.FFmpegFrameGrabber;  
import org.bytedeco.javacv.Frame; 
import org.bytedeco.javacv.FrameGrabber;  
import org.bytedeco.javacv.FrameRecorder;  
import org.bytedeco.javacv.OpenCVFrameConverter; 
import org.bytedeco.javacv.OpenCVFrameRecorder;  
import org.opencv.core.CvType;  
import org.opencv.core.Mat;

public class MainActivity extends AppCompatActivity {

Mat inImage,outImage;
opencv_core.Mat mat,mat2;
int state;
Frame outFrame = null;
Frame vFrame = null;
FrameGrabber videoGrabber;
FrameRecorder videoRecorder;
// Used to load the 'native-lib' library on application startup.
static {
    System.loadLibrary("native-lib");
    System.loadLibrary("opencv_java3");
}

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

    TextView tv = (TextView) findViewById(R.id.sample_text);
    tv.setText(R.string.msg);

    MyTask myTask = new MyTask();
    myTask.execute("Hello");

}

private class MyTask extends AsyncTask<String, String, Void> {

    String url;
    @Override
    protected Void doInBackground(String... params) {

        OpenCVFrameConverter.ToMat converterToMat = new OpenCVFrameConverter.ToMat();

        try
        {
            videoGrabber.start();
            Log.d("Status Check : ","Video Grabber started");

        } catch (Exception e){
            Log.e("Status Check :", "Failed to start grabber" + e);
        }

        try {
            videoRecorder.start();
        } catch (FrameRecorder.Exception e) {
            e.printStackTrace();
        }

        do
        try {
            vFrame = videoGrabber.grabFrame();
            if (vFrame != null) {
                mat = converterToMat.convert(vFrame);
                //if (mat != null) {
                Log.d("Status Check :", "Working...");
                inImage = new Mat(mat.address());

                state = processStateFromJNI(inImage.getNativeObjAddr(), outImage.getNativeObjAddr());

                if (state == 1) {
                    Log.d("Status Check :", "Starting process...");
                    mat2 = new opencv_core.Mat() { { address = outImage.getNativeObjAddr(); } };
                    Log.d("Status Check :", "Got mat2...");
                    outFrame = converterToMat.convert(mat2);
                    if(outFrame != null){
                        Log.d("Status Check :", "Starting to record video...");
                        videoRecorder.record(outFrame);
                        Log.d("Status Check :", "\n Process completed!!!");
                    }
                } else if (state == 0) {
                    Log.d("Status Check :", "\n Process not completed!!!");
                 //   }
                }
            }
        } catch (Exception e) {
            Log.e("Status Check :", "video grabFrame failed: " + e);
        } while(vFrame != null);

        return null;
    }

    @Override
    protected void onPostExecute(Void result) {

        super.onPostExecute(result);

        TextView tv = (TextView) findViewById(R.id.sample_text);
        tv.setText(tv.getText()+"\nonPostExecute!!!!!");

        try
        {
            videoGrabber.stop();
            videoRecorder.stop();
        }catch (Exception e) {
            Log.e("Status Check :", "failed to stop video grabber", e);
        }

        Log.d("Status Check", "Ended video processing...");

        if (state == 1) {
            tv.setText(tv.getText() + "\n Process completed!!!");
        } else if (state == 0) {
            tv.setText(tv.getText() + "\n Process Error!!!");
        }
    }

    @Override
    protected void onPreExecute() {
        inImage = new Mat(480,640, CvType.CV_8UC4);
        outImage = new Mat(480,640, CvType.CV_8UC1);
        videoRecorder = new OpenCVFrameRecorder(Environment.getExternalStorageDirectory().getPath()+"/output.avi",640,480);
        //videoRecorder.setVideoCodec(CV_FOURCC('M','J','P','G'));
        videoRecorder.setFrameRate(30);
        videoRecorder.setPixelFormat(1);

        videoGrabber = new FFmpegFrameGrabber(Environment.getExternalStorageDirectory().toString()+"/vtest.avi");
        videoGrabber.setFormat("avi");

        TextView tv = (TextView) findViewById(R.id.sample_text);
        tv.setText(tv.getText()+"\nonPreExecute!!!!!");
    }
}

/**
 * A native method that is implemented by the 'native-lib' native library,
 * which is packaged with this application.
 */
public native int processStateFromJNI(long matAddrRgba, long matAddrGray);  
}  

本机代码是

#include <jni.h>
#include <string>
#include <stdexcept>

#include <opencv2/opencv.hpp>
#include <opencv2/core.hpp>
#include <opencv2/objdetect.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/imgproc.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/video.hpp>
#include <opencv2/videoio.hpp>

#include <android/log.h>

#define LOG_TAG "FaceDetection/DetectionBasedTracker"
#define LOGD(...) (__android_log_print(ANDROID_LOG_DEBUG, LOG_TAG, __VA_ARGS__))


using namespace cv;
using namespace std;

int toGray(Mat img, Mat& gray);

extern "C" JNIEXPORT jint

JNICALL
Java_com_example_iq3_computervisionapp_MainActivity_processStateFromJNI(
        JNIEnv *env,
        jobject /*this*/, jlong addrRgba, jlong addrGray ) {
    Mat& mRgb = *(Mat*)addrRgba;
    Mat& mGray = *(Mat*)addrGray;

    LOGD("Before starting...");

    int conv;
    jint retVal;

    conv = toGray(mRgb,mGray);

    retVal = (jint)conv;

    return retVal;
}

int toGray(Mat img, Mat& gray){

    cvtColor(img,gray,CV_RGBA2GRAY);
    if(gray.rows == img.rows && gray.cols == img.cols){
        return 1;
    }
    else{
        return 0;
    }
}

我面临的问题是程序完全运行，但是未创建视频“ output.avi”。我已经在AndroidManifest.xml中提供了用于外部读写的权限。请告诉我我要去哪里了。欢迎任何链接和建议。