I need to run a Vimeo video in the video tag, how do I? I found it here:
<video src="http://player.vimeo.com/external/85569724.sd.mp4?s=43df5df0d733011263687d20a47557e4"></video>
Well, that's not my video, does anyone know how to explain it? Or how do you generate this URL?
Well, Vimeo does not allow you to have access to this raw video (.MP4), but you can easily do so by simply inspecting the page with your browser and removing the video snippet.
As for example the video below that I removed from the official site of the vimeo, just inspecting the element and copying the code snippet.
<video controls autoplay preload="" src="https://01-lvl3-pdl.vimeocdn.com/01/4863/2/74317104/189249795.mp4?expires=1505088239&token=0ea4e3812d7a0bf4aa0bb"></video>IfyouareusingGoogleChrome,doastheexampleofthisprint: 
I hope I have helped.
By default I use a formula in the URL.
In the example below, where identifier 141401442 is, use your.
<html>
<iframe id="playerSOpt" class='player' src='https://player.vimeo.com/video/141401442?title=0&byl&api=1&player_id=player_1' width='800px' height='600px' frameborder='0' ></iframe>
</html>