---
name: "XvQueryExtension"
section: "3"
platform: "linux"
package: "libxv"
version: "1.0.13-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/XvQueryExtension"
---

# XvQueryExtension(3)

return version and release of extension

## NAME

XvQueryExtension - 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)](/XvQueryExtension/3.md) 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)](/XvQueryExtension/3.md) completed successfully.

- \[XvBadExtension\]

  Returned if the Xv video extension is not available for the named display.

## SEE ALSO

[**Xv**(3)](/Xv/3.md)