class matchPair
public:
    matchPair(int a=0, int b=0)
        : m_a(a)
        , m_b(b)
    int a() const { return m_a; }
    int b() const { return m_b; }
    bool operator<(const matchPair &rhs) const { return m_a < rhs.a(); }
//    matchPair& operator=(const matchPair& other) const;
private:
    int m_a;
    int m_b;
class videodup
public:
    videodup(QString vid = "", int m_a = 0, int m_b = 0);
    ~videodup() {}
    QString video;
    bool operator==(const QString &str) const { return video == str; }
//  videodup& operator=(QString vid, int m_a, int m_b);
    QList<matchPair> matches;
struct frm
    QString file;
    int position;
    cv::Mat descriptors;