---
name: "XvGetPortAttribute"
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/XvGetPortAttribute/3x"
---

# XvGetPortAttribute(3x)

return current port attribute value

## Name

XvGetPortAttribute - return current port attribute value

## Syntax

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

**XvGetPortAttribute(*dpy, port, attribute, p\_value*)**

**Display** *\*dpy*;\
 **XvPortID** *port*;\
 **Atom** *attribute*;\
 **int** *\*p\_value*;

## Arguments

- *dpy*

  Specifies the connection to the X server.

- *port*

  Specifies the port, associated with the given display, for which the attribute values are to be returned.

- *attribute*

  An atom that identifies the attribute to be queried by this request.  Control atoms are obtained using the XInternAtom request with a string from the following table.

- *p\_value*

  Pointer to the location where the attribute value is written on return.

## Description

[XvGetPortAttribute(3x)](/XvGetPortAttribute/3x.md) returns the current value of the requested port attribute in the integer pointed to by *p\_value*.   The attribute is identified using an Atom that equates to the attribute name.   The XInternAtom request can be used with one of the strings below to return a matching Atom.

```
Attribute String        Type             Default
"XV_ENCODING"           XvEncodingID     Server dependent
"XV_HUE"                [-1000...1000]   0
"XV_SATURATION"         [-1000...1000]   0
"XV_BRIGHTNESS"         [-1000...1000]   0
"XV_CONTRAST"           [-1000...1000]   0
```

## Returned Values

- \[Success\]

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

- \[XvBadExtension\]

  Returned if the Xv extension is unavailable.

- \[XvBadAlloc\]

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

## Diagnostics

- \[XvBadPort\]

  Generated if the requested port does not exist.

- \[BadMatch\]

  Generated if the requested attribute atom does not specify an attribute  supported by the adaptor.

## See Also

[XvSetPortAttribute(3x)](/XvSetPortAttribute/3x.md), [XvPortNotify(3x)](/XvPortNotify/3x.md)\