XvGetPortAttribute(3X) 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