Go to chrome://flags, search for Autoplay policy, and select Document user action is required.
Note that if you use the Imagus extension, this could block some videos/gifs/etc from playing when you hover over a link.
Quoting the blog post, Google’s decision that ”Muted autoplay is always allowed” is the problem. If any other Chrome users wondered why videos now auto-play without sound (even with this option set), at least based on the relatively minimal docs about this flag, this is why.
I can't seem to find the issue, but in the Safari issue tracker, the point was made that given the way HTML5 video and APIs work, it is impossible to reliably prevent autoplay without breaking some sites. It seems that Firefox went for "reliably prevent autoplay" while Chrome went for "without breaking sites".
FWIW, I switched from Chrome to Firefox because of the autoplay issue.