man XvGetPortAttribute (Fonctions bibliothèques) - 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 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.
- 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(3) 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(3) completed successfully.
- [XvBadExtension]
- Returned if the Xv extension is unavailable.
- [XvBadAlloc]
- Returned if XvGetPortAttribute(3) 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.