XvGrabPort - lock port for exclusive use by client
#include <X11/extensions/Xvlib.h>
int XvGrabPort(Display *dpy, XvPortID port, Time time);
  - dpy
- Specifies the connection to the X server.
- port
- Defines the port to be grabbed.
- time
- Specifies the request timestamp.
XvGrabPort(3) grabs a port. Once a client grabs a port, only that client
  can make video requests to that port.If the time is before the current port time, the XvGrabPort
    request is ignored and XvInvalidTime is returned. If the port is already
    grabbed by another client, XvAlreadyGrabbed is returned. Otherwise it
    returns a status of Success. The port time is updated when the
    following requests are processed: XvGrabPort(3),
    XvUngrabPort(3), XvPutVideo(3), XvPutStill(3),
    XvGetVideo(3), XvGetStill(3).
If the port is actively processing video for another client, the
    video is preempted, and an XvVideoNotify event with detail XvPreempted is
    generated for its drawable.
  - [Success]
- Returned if XvGrabPort(3) completed successfully.
- [XvInvalidTime]
- Returned if requested time is older than the current port time.
- [XvAlreadyGrabbed]
- Returned if the port is already grabbed by another client.
- [XvBadExtension]
- Returned if the Xv extension is unavailable.
- [XvBadAlloc]
- Returned if XvGrabPort(3) failed to allocate memory to process the
      request.
  - [XvBadPort]
- Generated if the requested port does not exist.
XvUngrabPort(3), XvVideoNotify(3)