OpenCV阻塞了我的GTK接口

我用GTK3编写了一个非常简单的GUI，有三个按钮：

• 启动：调用OpenCV VideoCapture
• 停止：停止VideoCapture
• 退出：破坏窗口

当我点击"停止"时，问题就出现了，OpenCV进程会阻塞GUI，并且命令会在几秒钟（通常是一分钟）后执行。

这是我的主菜：

bool stop = false;
static void start_webcam (GtkWidget *widget, gpointer   data)
{
    cout<<"Webcam On"<<endl;
    int err = 0;
    **err = opencv_webcam(); // this function loads the OpenCV Webcam**
    // troubles?
    if (err != 0)
    {
        cout<<"Unable to load the webcam. Error Code # "<<err<<endl;
    }
}
static void stop_webcam (GtkWidget *widget, gpointer  data)
{
    stop = true;
    cout<<"Webcam Off"<<endl;
}
int main (int   argc, char *argv[])
{
    // Widgets
    GtkWidget *window;
    GtkWidget *grid;
    GtkWidget *button;
    // GTK Init
    gtk_init (&argc, &argv);
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title (GTK_WINDOW (window), "WEBCAM CONTROL PANEL");
    g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), NULL);
    gtk_container_set_border_width (GTK_CONTAINER (window), 10);
    grid = gtk_grid_new ();
    gtk_container_add (GTK_CONTAINER (window), grid);
    /// START WEBCAM
    button = gtk_button_new_with_label ("Start");
    g_signal_connect (button, "clicked", G_CALLBACK (start_webcam), NULL);
    gtk_grid_attach (GTK_GRID (grid), button, 0, 0, 1, 1);
    /// STOP WEBCAM
    button = gtk_button_new_with_label ("Stop");
    g_signal_connect (button, "clicked", G_CALLBACK (stop_webcam), NULL);
    gtk_grid_attach (GTK_GRID (grid), button, 1, 0, 1, 1);

    /// QUIT
    button = gtk_button_new_with_label ("Quit");
    g_signal_connect (button, "clicked", G_CALLBACK (gtk_main_quit), NULL);
    gtk_grid_attach (GTK_GRID (grid), button, 0, 1, 2, 1);

    /// GO!
    gtk_widget_show_all (window);
    gtk_main ();

    return 0;
}

我想为"退出"按钮设置一些高优先级。我尝试在Windows中通过SetPriorityClass（）设置main中的最高优先级，但没有成功。

非常感谢！

编辑

这是我的openCV代码：

extern bool stop;
int opencv_webcam()
{
    /// Various stuff
    cv::Mat frame;
    cv::namedWindow("Webcam Session");
    /// Webcam Opening
    cv::VideoCapture clip(0);
    while(stop != true)
    {
        // frames extraction
        clip.grab();
        clip.retrieve(frame);
        // troubles?
        if ((frame.empty()==1))
        {
            // errore!
            return -1;
        }
        /// SHOW the frames
        cv::imshow("Webcam Session", frame);
        if (waitKey(30)>= 0)
        {
            break;
        }
    }
    return 0;
}