How to put an alternative picture instead of a video?

Question

css

Good day! On the site you need to put a video instead of the background. I registered it with the tag. Everything works well, but on android it is not displayed everywhere. I decided to put the image as alternative content if the video doesn't play.
Here is the code:

<video autoplay loop>
    <source src="b_video/eldorado_bg.webm" type="video/webm"/>
    <source src="b_video/eldorado_bg.mp4" type="video/mp4"/>
    <source src="b_video/eldorado_bg.ogv" type="video/ogg"/>
          <OBJECT data="logo.png" type="image/png">
          </OBJECT>
  </video>

But the picture still does not go as alternative content.
Tell me how to put it right?
Thank you!

Answer 1

www.w3schools.com/tags/att_video_poster.asp
poster="/images/something.jpg"