This video was created using Tao Presentations, which uses XLR as a document description language. The XLR program runs in real-time, 60 times per second, to update page contents. In that specific case, it synchronizes the various text and 3D object animations with the background video.
Attached is the whole code (
Voeux.ddd) if you want to get an idea of what this looks like.
Credits for the original video: PhotoByNight69