OpenCV多线程相机读取

Question

我正在尝试使用OpenCV通过单独的线程工作者从多个摄像头捕获图像。

最终，CaptureWorker会将帧提供给工作队列进行处理，但目前我还想保存图像。以下代码运行，但保存的“＃”框架＆＃39;已损坏，无法打开，但不是空的。

最初，我在CaptureWorker :: startCapture（）中构建和存储VideoCapture;但是，程序在打开流时崩溃了。在main（）中构建和打开VideoCapture会打开相机并允许线程运行。

是什么导致帧写入中断？没有报告错误。

的main.cpp

int main(int argc, char * argv[]) {

    if(argc <= 1) {
        cout << "No camera arguments have been specified. Exiting." << endl;
        return -1;
    }

    int numberOfCameras = argc - 1;
    int cameraNumbers[argc-1];

    for(int i=0; i<numberOfCameras; i++) {
        cameraNumbers[i] = atoi(argv[i+1]);
    }

    VideoCapture cameras[10];
    pthread_t cameraThreads[numberOfCameras];

    for(int i=0; i<numberOfCameras; i++) {
        cout << "Creating camera thread: " << i << endl;
        cameras[i] = VideoCapture(i);
        CaptureWorker capWorker(cameras[i], i);
        pthread_create(&cameraThreads[i], NULL, &CaptureWorker::startCaptureWrap, &capWorker);
    }

    cout << "Closing Main" << endl;
    pthread_exit(NULL);
} 

CaptureWorker.cpp

class CaptureWorker {

private:
    int cameraNumber;
    string cameraName;
    VideoCapture camera;

public:
    CaptureWorker(VideoCapture camera, int cameraNumber) {
        this->cameraNumber = cameraNumber;
        this->camera = camera;
        this->cameraName = "Camera_";
        cameraName.append(to_string(cameraNumber));
        cout << "CaptureWorker: Worker created" << endl;
    }

    void *startCapture(void) {
        string imageSavePath = "Resources/images/" + this->cameraName;
        mkdir(imageSavePath.c_str(), 0777);

        cout << "CaptureWorker: Starting capture from camera" << endl;
        int count = 0;
        while(count <= 3) {
            cout << "Capturing frame " << count;
            Mat frame;
            this->camera >> frame;
            cout << " --- ";

            string imageNameAndPath;
            imageNameAndPath.append(imageSavePath);
            imageNameAndPath.append("/img_");
            imageNameAndPath.append(to_string(count).c_str());
            imageNameAndPath.append(".jpg");

            cout << "Saving to: " << imageNameAndPath.c_str() << endl;
            imwrite(imageNameAndPath.c_str(), frame);

            int c = cvWaitKey(1000);
            if((char)c==27 ) {
                break;
            }
            count++;
        }
        return 0;
    }

    static void *startCaptureWrap(void *arg) {
        return ((CaptureWorker *) arg)->startCapture();
    }
};

在OSX中使用eclipse中的交叉g ++编译器。免责声明：C ++，OpenCV，多线程的新手，希望我避免了一个愚蠢的错误。