I created this project starting with subtitles creation for my 7 years old son. Than added video highlighting and finally it evolves in offline video analyzer on which are working group of 3 close friends.
Free AGPL: https://github.com/Aseiel/VideoHighlighter Demo: https://github.com/Aseiel/VideoHighlighter#demo Site: https://aseiel.github.io/VideoHighlighter-site/
There is optional Pro version.
There is simple view for highlight creation and advanced timeline when You can drag and drop all signals as small boxes.
Happy to answer any questions.