Embedding video content (stored in Plone) with a page/TinyMCE

It's trivial nowadays to add an external video e.g. directly for a given YouTube URL or some embedding code into Plone using "Insert media" in TinyMCE. But how do you embed video "File" stored directly in Plone in the same way? What is preferred solution here (constraint: Plone 5.2, Python 3)?

wildcard.media, python3 branch is likely the way to go

Working with Plone 5.2, Python 3 so far..TinyMCE integration seems to be broken so far.