.TH XvGetPortAttribute __libmansuffix__ __vendorversion__
.\" $XFree86: xc/doc/man/Xv/XvGetPortAttribute.man,v 1.6 2001/01/27 18:20:35 dawes Exp $
.SH Name
XvGetPortAttribute \- return current port attribute value
.\"
.SH Syntax
.B #include <X11/extensions/Xvlib.h>
.sp 1l
.B XvGetPortAttribute(\fIdpy, port, attribute, p_value\fR)
.sp 1l
\fBDisplay \fI*dpy\fR;
.br
\fBXvPortID \fIport\fR;
.br
\fBAtom \fIattribute\fR;
.br
\fBint \fI*p_value\fR;
.sp 1l
.\"
.SH Arguments
.\"
.IP \fIdpy\fR 8
Specifies the display screen on which the
X Server is to accept requests from X clients.  If the
display option is not specified, X uses the display screen
specified by your DISPLAY environment variable.  The display
option has the format hostname:number.  Using two colons
(::) instead of one (:) indicates that DECnet is to be used
for transport.
.IP \fIport\fR 8
Specifies the port, associated with the given display, for
which the attribute values are to be returned. 
.IP \fIattribute\fR 8
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.
.IP \fIp_value\fR 8
Pointer to the location where the attribute value is written on
return.
.\"
.SH Description
.\"
.PP
XvGetPortAttribute(__libmansuffix__) returns the current value of the requested
port attribute in the integer pointed to by \fIp_value\fR.  
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.
.bp
.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
.nf
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
.fi
.SH Returned Values
.IP [Success] 8
Returned if XvGetPortAttribute(__libmansuffix__) completed successfully.
.IP [XvBadExtension] 8
Returned if the Xv extension is unavailable.
.IP [XvBadAlloc] 8
Returned if XvGetPortAttribute(__libmansuffix__) failed to allocate memory to process
the request.
.SH Diagnostics
.IP [XvBadPort] 8
Generated if the requested port does not exist.
.IP [BadMatch] 8
Generated if the requested attribute atom does not specify an attribute 
supported by the adaptor.
.SH See Also
.\"
XvSetPortAttribute(__libmansuffix__), XvPortNotify(__libmansuffix__)
.br