Divi uses a stucture of Sections, Rows and Modules. The section is the base level that can contain one or more rows. Rows may contain one or more modules. Sections and Rows are basically containers.
The previous examples I tried used the video as a background to the section. Therefore there are no specific video controls and the video tries to fill the entire Section background (and scales automatically).
The example above comprises a Section, a Row and a Module (video module). The Section has a black background, The row has no background (transparent) and the module has no background (transparent).
The video module has the scaled down video and presents the correct aspect ratio. However the module cannot be full width. I have however used Divi’s Transform tool to enlarge the video module so that it fills more of the container. This is a test only and I am unsure as to how it will look on different resolution devices. But is is better I think.