XvQueryExtension(3) return version and release of extension

SYNOPSIS

#include <X11/extensions/Xvlib.h>

int XvQueryExtension(Display *dpy, unsigned int *p_version,
unsigned int *p_revision,
unsigned int *p_request_base,
unsigned int *p_event_base,
unsigned int *p_error_base);

ARGUMENTS

dpy
Specifies the connection to the X server.
p_version
Pointer to where the current version number of the Xv video extension is written.
p_revision
Pointer to where the revision number of the Xv video extension is written.
p_request_base
Pointer to where the extension major request number is returned
p_event_base
Pointer to where the extension event base is returned
p_error_base
Pointer to where the extension error base is returned

DESCRIPTION

XvQueryExtension(3) returns the version and release numbers for the Xv video extension currently loaded on the system. The extension major request number, event base, and error base are also returned.

RETURN VALUES

[Success]
Returned if XvQueryExtension(3) completed successfully.
[XvBadExtension]
Returned if the Xv video extension is not available for the named display.