Announced by Jer Noble in a post to the WebKit blog on Monday, the forthcoming changes come thanks to new WebKit policies regarding how the browser engine handles video elements.
In a bid to improve user experience, Apple’s mobile Safari web browser in iOS 10 will autoplay silent videos and pause those with sound, a change that enables automatic playback of GIFs — at least those converted to video — while halting potentially disruptive content like ads.
Currently, WebKit policies require a user gestures, like a tap or touch, to play media in video and audio elements in Safari for iOS. The restrictions were initially implemented to save on operating bandwidth and power usage, but came at the cost of a somewhat clunky user interface.
More importantly, Safari gesture requirements can in some cases prevent media-rich webpages from rendering correctly, making them unusable.
WebKit’s new policies are crafted to take into consideration both the correct presentation of video elements and the costs of displaying those elements in Safari. As a result, WebKit will allow video elements to autoplay without a user gesture if the source media contains no audio track or if that track is muted. Once an audio track is detected, or if the track becomes un-muted without user intervention, playback will automatically pause. Playback also stops when the element is no longer visible on screen.
Further, video media encoded as an inline element will no longer default to fullscreen playback.
For end users, the policy modifications should deliver a more intuitive experience when browsing modern webpages in Safari. For example, WebKit’s policies will afford automatic playback of popular animated GIF images (a number of major GIF providers now convert the resource-intensive format into bite-sized video elements).
Apple is expected to release iOS 10 alongside a next-generation iPhone lineup this fall.