If only iOS (and Android?) allowed you to play inline videos the way you can on the desktop, and the way they play animated GIF's inline. Besides allowing us to adopt video throughout and save on bandwidth and have better video quality, this will be a huge productivity boost to developers: we can finally stop having the GIF vis JIF pronunciation debate.
I think this should definitely be an option. This is a really personal preference and there is no reason you should suffer through autoplay videos if you don't want to.
I would want it on, at least for some sites, like Gyfcat and Imgur because otherwise my phone slows down to a crawl, trying to load and render a GIF.
To replace GIFs. I don't have a problem with users being able to opt out, etc. But GIF's are still useful, yet a huge drain on resources. If for nothing, I want my cat videos still available inline without having to click them.
Hardware video decoders mostly only handle one video at a time and if you could multiplex the one decoder the chip has, to keep up with multiple videos playing at once it just might take a milliwatt or two.
I never wanted any movable ads while trying to read something on the phone. Even less the movable the cat gifs. If something is not worth the click, it's certainly not worth to be inline in the text.
AFAIK the Apple Watch doesn't support video of any sort, so if you want to get moving pictures on your watch the gif is the only way. Gif is about to make a comeback if anything.
is it possible to have pixel-perfect animations (avoid compression artifacts completely) while using h.264 or VP8 and still get good filesize?
also, what about alpha transparency? video formats do not have this. GIF is shitty for video clips, but it's not without uses. it just needs to be replaced by APNG [1].
