---
name: "XvQueryExtension"
section: "3x"
platform: "linux"
package: "libxv-dev"
version: "1:1.0.2-1"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/XvQueryExtension/3x"
---

# XvQueryExtension(3x)

return version and release of extension

## Name

XvQueryExtension - return version and release of extension

## Syntax

**#include \<X11/extensions/Xvlib.h\>**

**XvQueryExtension(***dpy, p\_version, p\_release,* \
\
 	*p\_request\_base, p\_event\_base, p\_error\_base*)

**Display** *\*dpy*;\
 **unsigned int** *\*p\_version, \*p\_release*;\
 **unsigned int** *\*p\_request\_base, \*p\_event\_base, \*p\_error\_base*;

## Arguments

- *p\_version*

  Pointer to where the current version number of the *Xv* video extension is written.

- *p\_release*

  Pointer to where the release 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(3x)](/XvQueryExtension/3x.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.

## Returned Values

- \[Success\]

  Returned if [XvQueryExtension(3x)](/XvQueryExtension/3x.md) completed successfully.

- \[XvBadExtension\]

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

- \[XvBadAlloc\]

  Returned if [XvQueryExtension(3x)](/XvQueryExtension/3x.md) failed to allocate memory to process the request.\