The ONVIF WSDL specs and schema definitions are retrieved from below url:

http://www.onvif.org/onvif/ver10/device/wsdl/devicemgmt.wsdl
http://www.onvif.org/ver20/ptz/wsdl/ptz.wsdl
http://www.onvif.org/onvif/ver10/media/wsdl/media.wsdl
http://www.onvif.org/ver10/schema/onvif.xsd

Currently the converted spec doesn't contain schema definition to variables in object type, user should consult original ONVIF WSDL specs in order to dereference them