See this example properly formatted in the QUT Cite tool.
Standard in-text citation examples are in Getting started - In-text citation.
Author AA. Unit Code Title [Format]. Place of publication: Publisher; Year [cited Year Month Day]. Available from http://www.xxx.xxx.xxx
Dunbabin M. EGB100 The Engineering Method [Online lecture recording]. Brisbane (QLD): Queensland University of Technology; 2016 [cited 2016 Mar 22]. Available from http://blackboard.qut.edu.au
The URL for the Blackboard homepage is provided rather than that of the specific page.
For notes about a lecture made available through Blackboard see Blackboard material.