HTML and CSS Reference
Support for HTML5 audio and video, especially video, in mobile devices is varied and can be
challenging for web page authors and designers.
Challenges of a Mobile Environment
There are known quirks about the use of the HTML5 media elements in mobile devices. For
instance, Apple has been a big fan of HTML5 from the beginning, deciding against support
for Flash on iOS devices in favor of HTML5 video. However, some things that work on the
desktop don't in an Apple mobile environment. As an example, using the poster attribute
caused the video element to fail in iOS 3, though this problem has been fixed in iOS 4. Anoth-
er interesting little quirk was iPad's only checking the first source element, so you needed to
place the MP4 video first in the list (again, since corrected).
In addition, the iOS environment has its own native application for playback control, so it ig-
nores the controls attribute.
Then there are the issues of how to test your HTML5 media applications. Most of us can't
afford to buy half a dozen devices (some of us can't afford to buy any) and emulators don't
really work when it comes to testing out hardware and resource limitations.
A good article on the issues of mobile testing is “Testing Apps For SmartPhones and Mobile
Devices (Without Buying Out the Store)” at http://www.softwarequalityconnection.com/2011/03/
Most importantly, the video capability itself is limited in mobile environments. There is the
resolution/size issue, of course, but there are also issues with containers and codecs. Mobile
devices don't have the processing power our computers have, which means that the file sizes
are larger (because of simpler compression techniques). At the same time, mobile devices
have data access limitations as well as issues with storage, so larger files aren't mobile-
There's also the challenge associated with the sheer number of mobile operating systems, mo-
bile browsers, and devices—especially devices.