While searching Omni, the library catalogue, find "Modify your results" panel on the left side of the web page, allowing to refine your search by many parameters, including Resource Type. Under "Resource Type" (Articles, Conference Proceedings, Book Chapters, and so on) click on "Show more" where  you may find  "Videos", "Images", "Web Resources" and "Audio".  Click on any of this buttons to refine your search by this particular media type.

We also have another, not-library collection: Media Resources provides, maintains and develops a collection of media to supplement the University of Waterloo's academic curriculum and research needs. The purpose of the collection is to provide video content to supplement classroom teaching. The online catalogue of this collection is available.