Is there a way to let embedded videos (primarily Flash, but I'd prefer something that will also work with HTML5 video) automatically background load, but not start playing until explicitly started?
The typical use case where I want this ability is when opening a number of what I expected to be text pages in separate tabs using middle-clicks only to have something start yapping at me; at which point I need to click through all the new tabs to find and stop the offender.
I'd prefer not to completely block video download to avoid the startup delay if I decide to watch the video when I view the page its embedded in.
Best Answer
For embeded videos you can set media.autoplay.enabled to false in about:config.
For flash-players you can either disable automatic flash loading/start with some addon or use custom addons/greasemonkey scripts to disable each specific player's autoplay. For example: http://userscripts.org/scripts/show/13333