基类

class CameraOpt{
public:
    QLabel label;
    int type;//1 DH;2、HIK；3、OpenCV初始化时根据这个字段来区分这个类是那个子类的
    Param param;

public:
    bool virtual openVideo();

    bool virtual closeVideo();

    bool virtual getVideoStatus();
protect:
    bool virtual initParam();
}

子类CameraOptOpenCV

class CameraOptOpenCV : public CameraOpt{
    public:
        VideoCapture cap;
        Mat mat;

    public:
        bool openVideo() override;

        bool closeVideo() override;

        bool getVideoStatus() override;

    protected:
        bool initParam() override;
}

子类 CameraOptSDK

class CameraOptSDK : public CameraOpt{
    public:
        bool virtual ratate();//旋转
        bool virtual ptz();
        bool virtual wiper();//雨刷

    private:
        bool virtual login();
        bool virtual logout();
}

子类 CameraOptDH

class CameraOptDH : public CameraOptSDK{
    public:
        bool openVideo() override;

        bool closeVideo() override;

        bool getVideoStatus() override;

        bool ratate() override;

        bool ptz() override;

        bool wiper() override;

    protected:
        bool initParam() override;

    private:
        bool login() override;
        bool logout() override;
        LONG port = -1;
}

子类 CameraOptHIK

class CameraOptHIK : public CameraOptSDK{
    public:
        bool openVideo() override;

        bool closeVideo() override;

        bool getVideoStatus() override;

        bool ratate() override;

        bool ptz() override;

        bool wiper() override;

    protected:
        bool initParam() override;

    private:
        bool login() override;
        bool logout() override;

        friend void CALLBACK realDataCallback(LLONG lRealHandle);
}

结构基本上如图

问题

我想通过 CameraOpt的属性 flag ，将其动态类型转换为各个子类，完成对子类方法的调用。
即在项目中有多个CameraOpt指针，当需要使用时，对其flag对象赋值，然后动态类型转换为对应的子类，完成那么多方法操作……

怎么便捷地把CameraOpt转换为各子类？