it doesnt do anything at all

Twitch being the worst affected. Video doesn't load at all when it's not whitelisted.

Do the job on some website (not all), but breaks some others too, and sometime adblocks.

I've had a few websites break with this enabled.

As of a week ago (8th September) it doesn't seem to work with YouTube videos any more. It is a real shame as I've found the add-on to be very useful, and I hope this issue can be fixed quickly. Come on, dev, we know you can do this! ;·)

doesn't always work on youtube

Ttffy

Can`t play youtubes video. It even block play button!

You deserve some sort of medal for getting cnn.com to STFU.

No, seriously, they try to load and play their videos in at least a half dozen ways ....

Disable preloading doesn't work.
Non autostart works well on youtube, I like the option to enable/disable it at any point without having to go the plugins page

It simply doesn't work with the BBC News site. I've removing this pile of junk!

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