'\" t
.TH XvSetPortAttribute 3  "libXv 1.0.12" "X Version 11" "libXv Functions"
.SH NAME
XvSetPortAttribute \- sets an attribute of a video port
.\"
.SH SYNOPSIS
.B #include <X11/extensions/Xvlib.h>
.sp
.nf
.BI "int XvSetPortAttribute(Display *" dpy ", XvPortID " port ","
.BI "                       Atom " attribute ", int " value ");"
.fi
.SH ARGUMENTS
.\"
.IP \fIdpy\fR 15
Specifies the connection to the X server.
.IP \fIport\fR 15
Specifies the port for which the attribute is to be used.
.IP \fIattribute\fR 15
Identifies the port attribute to be set by this request.
Can be one of the table entries under the column "String," below.
.IP \fIvalue\fR 15
Identifies the value to which \fIattribute\fP is to be set.
Can be one of the table entries under the column "Type," below.
.\"
.SH DESCRIPTION
.BR XvSetPortAttribute (3)
 permits a client to set the port attribute
to specified values.  This request supports the following values:
.PP
.TS
tab(@);
lfHB lfHB lfHB
lfR  lfR  lfR .
_
.PP
.sp 4p
Attribute String@Type@Default
.sp 6p
_
.sp 6p
"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
.sp 6p
.TE
.PP
The supplied encoding must be one of the encodings listed for the
adaptor, otherwise an Encoding error results.
.PP
If the adaptor does not support the exact hue, saturation,
brightness, and contrast levels supplied, the closest levels
supported are assumed.  Use
.BR XvGetPortAttribute (3)
to query the resulting levels.
.PP
When an
.BR XvSetPortAttribute (3)
request is processed, a
.BR XvPortNotify (3)
event is generated for all clients that have requested notification of
port changes using
.BR XvSelectPortNotify (3).
.SH RETURN VALUES
.IP [Success] 8
Returned if
.BR XvSetPortAttribute (3)
completed successfully.
.IP [XvBadExtension] 8
Returned if the Xv extension is unavailable.
.IP [XvBadAlloc] 8
Returned if
.BR XvSelectVideoNotify (3)
failed to allocate memory to process the request.
.SH DIAGNOSTICS
.IP [XvBadPort] 8
Generated if the requested port does not exist.
.IP [XvBadEncoding] 8
Generated if an encoding is specified that does not exist.
.IP [BadMatch] 8
Generated if the requested attribute atom does not specify an attribute
supported by the adaptor.
.SH SEE ALSO
.\"
.BR XvGetPortAttribute (3),
.BR XvQueryPortAttributes (3),
.BR XvSelectPortNotify (3),
.BR XvPortNotify (3)