There is a disable autoplay in Firefox as a hidden pref. Enabling it break YouTube (offender number 1) and Vimeo.
Vimeo's take is that it is a bug in the browser hence it should be fixed. But then Vimeo are the same that told use to use Safari on Linux because Firefox "didn't support HTML5" (it did, just not encumbered H264 codec, but when you are lying, do the extra mile).
Vimeo's take is that it is a bug in the browser hence it should be fixed. But then Vimeo are the same that told use to use Safari on Linux because Firefox "didn't support HTML5" (it did, just not encumbered H264 codec, but when you are lying, do the extra mile).