How to disable HTML5 autoplay in Chrome and Firefox

I don't like many web sites automatic play the video in HTML5. I just slow me down and annoy.

To disable it:

For Google Chrome: No way to do it unless I install the add-on plug-in or extension. I don't like that. So just be patient to wait for Google provide that feature or try Eloston extension

For Mozilla Firefox: Set media.autoplay.enabled to false in about:config (Source: http://superuser.com/questions/670214/how-can-i-disable-html5-content-in-popular-browsers-like-firefox-and-chrome ).

Note: Never, never run or enable Adobe Flash player.