typedef union {
        int type;
        XvVideoNotifyEvent xvvideo;
        XvPortNotifyEvent xvport;
        long pad[24];
      } XvEvent;
      typedef struct {
        int type;
        unsigned long serial;
        Bool send_event;
        Display *display;
        Drawable drawable;
        unsigned long reason;
        XvPortID port_id;
        Time time;
      } XvVideoNotifyEvent;
Specifies the type of event: XvVideoNotify(3X) .
Number of the last request processed by the server.
True if the event was generated by a SendEvent request.
A pointer to the display the event was read from.
The drawable for which the event was generated.
The reason the event was generated: XvStarted, XvStopped, XvPreempted, XvBusy, XvHardError.
The port processing the video for which the event was generated.