Is there a way to turn this off? Would an adaptation of @david’s pull request dealing with datamotion videos work?
The problem is especially confusing/annoying if the user follows a link to a post deep in a topic and a video at the top of the topic starts playing automatically.
I do see in both Firefox and Chrome. Agree that it is annoying. Did you notice that the video re-starts if you re-load the page?
I do see that the iframe link rendered in the no-script zone has “autoplay=1”. I’m wondering if this is partly due to how the embed link is being created by Vimeo?
That’s odd – when I try and embed the same video on the latest version of Discourse it doesn’t autoplay. I saw that your forum is using a relatively recently install, so I wonder if Vimeo was temporarily returning autoplay markup from opengraph?
Can you try posting a different vimeo video on your forum? I suspect it won’t autoplay anymore. You should be able to edit the post with the autoplaying video and it will update the onebox.