Pierluigi Paganini
December 21, 2015
It may help the fact that Facebook is leaving Flash behind and it is adopting HTML5 (YouTube has done in the a recent past).
“We recently switched to HTML5 from a Flash-based video player for all Facebook web video surfaces, including videos in News Feed, on Pages, and in the Facebook embedded video player. We are continuing to work together with Adobe to deliver a reliable and secure Flash experience for games on our platform, but have shipped the change for video to all browsers by default.” States the announcement issued by Facebook.
“From development velocity to accessibility features, HTML5 offers a lot of benefits. Moving to HTML5 best enables us to continue to innovate quickly and at scale, given Facebook’s large size and complex needs.”
We are big supporters of the HTML5 since it eliminates the weakest link in the user environment and in terms of development, it makes the job easier for developers.
Facebook explains the benefits of HTML5 that they will be using:
Development velocity
“Using web technologies allows us to tap into the excellent tooling that exists in browsers, among the open source community, and at Facebook in general. Not having to recompile code and being able to apply changes directly in the browser allow us to move fast.”
Testability
“We have an excellent testing infrastructure at Facebook. By moving to HTML5 video, we can avail ourselves of all the web tools in that infrastructure, like jest and WebDriver, at our disposal.”
Accessibility
“HTML5 made it possible for us to build a player that is fully accessible to screen readers and keyboard input. We can leverage the accessibility tools that HTML5 provides to make it easier for people with visual impairments to use our products. Making Facebook accessible to everyone is an important part of our mission to make the world more open and connected.”
When doing such a big move, there are challenges that needs to be overcome, and Facebook is no exception, and for that reason Facebook needed to:
Getting logging right
“To ensure logging correctness, we created a test suite that performs the same user-interaction scenarios against both video players and then validates that the logs are equivalent. This way we had high confidence in the data that our new HTML5 video player reports.”
Browser bugs
“One of the major issues we wanted to solve before shipping the HTML5 player was the number of bugs in various browsers around HTML5 videos. One specific bug in Chrome’s implementation of the SPDY protocol caused the browser to simply stop loading and playing videos in News Feed. We determined that the issue was triggered by loading too many videos concurrently, so we reduced the number of videos we load at the same time and make sure we cancel loading videos as soon as they are no longer required.”
Worse performance in older browsers
“In theory, most browsers in use support HTML5 video. However, in practice we noticed that a lot of the older browsers would simply perform worse using the HTML5 player than they had with the old Flash player. We saw more errors, longer loading times, and a generally worse experience. We decided to initially launch the HTML5 player to only a small set of browsers, and continuously roll out to more browsers, versions, and operating systems as we improved it and fixed small bugs. That’s why we waited until recently to ship the HTML5 player to all browsers by default, with the exception of a small set of them.”
Page load time regression
“The last major issue we faced while launching the HTML5 player was a regression in the time it takes to load Facebook. At Facebook, we care about the experience we provide to people. How long Facebook takes to load is a contributing factor we look at to gauge user experience. When we shipped the HTML5 player, we noticed that on average it took slightly longer for Facebook to load. By fixing several small performance regressions and making multiple micro-optimizations, we finally reached a level we felt happy with shipping.”
As said before, this can be a huge improvement for the user but also for the developers. On the user side, they will have an improved video experience, videos will start playing faster which is good.
It is good that big companies like Facebook and Google are adopting HTML5 forcing sooner or later other websites to switch to HTML5, making everyone a bit safer.
About the Author Elsio Pinto
Edited by Pierluigi Paganini
(Security Affairs – HTML5, Flash)
