Use the built-in feature in Firefox instead:

1. Type about:config in the address bar and hit Enter.
2. Accept the warning to continue.
3. Search for media.autoplay.enabled and change the value to false by double-clicking on the row.

Enjoy your much better solution all through a built-in feature!

Installed it, tried to test at this link:
http://money.cnn.com/2017/07/18/news/economy/obamacare-trump-fail/index.html

And guess what? The adds autoplayed, the video autoplayed. The add-on simply doesn't work.

This extension causes the following prompt for MP4/H.264 videos.
"Video format or MIME type is not supported."

Test link: http://www.html5videoplayer.net/html5video/mp4-h-264-video-test/

Environment: Windows 7 (64-bit), Firefox Nightly (64-bit), OpenH264 Video Codec provided by Cisco Systems is enabled

好的很

good

It works the way it should. There are problems on some sites but all the major sites work well. I think that the author will fix minor problems in future versions. The main thing that would not abandon the addon. :)

I found these instructions and they work. You can disable HTML5 autoplay natively without an add-on.

http://www.pcworld.com/article/3119886/software/stop-html5-autoplay-videos-in-chrome-firefox-opera-but-not-edge-explorer-safari.html

Does not prevent autoplay on TV GUide

thanks a lot

Go over to the huffington post's website and load any page. It will autoplay even with this enabled.