HTML5 (Part 4) Playing <audio> and <video>
In recent years, the popularity of video sharing sites such as YouTube and content delivery platforms like Hulu has seen a huge explosion in the use of the Web for multimedia streaming.
Unfortunately, the Web was not built with such content in mind, and as a result, the provision of video and audio has by and large been facilitated by the Flash Video (.flv) file format and the Adobe Flash platform.
HTML5, however, includes support for two new elements,<audio> and <video> , which allow Web developers to include multimedia content without relying on the
user to have additional browser plug-ins installed.
Several browsers, including Mozilla Firefox, Apple Safari, and Google
Chrome, have begun supporting these new elements and providing standard
browser playback controls, should the user choose to use them.
In addition, a set of standard JavaScript APIs has been provided to
allow developers to create their own playback controls, should they
wish to do so.
A key advantage to native multimedia playback is that it theoretically
requires less CPU resources, which can lead to energy savings.
A key issue with these new multimedia elements, however, is the file formats supported by each browser and the patent licensing
issues that go along with the various codecs that these files can be
encoded with. Mozilla and Opera want to use the open source Theora
video container and codec, which does not requirepatent licensing for the inclusion of the codecs in the Web
browser. On the other hand, Apple and Google are not happy with the
quality of Theora, particularly for the delivery of high definition
(HD) content on the likes of YouTube. They prefer the H.264 codec,
typically contained in MP4, MOV, or MKV files.
The issue is not just with video however, as the same problems reside
with audio codecs. The MP3 and AAC formats are restricted by patents,
whereas the Vorbis format is not. The problem with Vorbis audio is that
it is not in widespread use, as portable media players and many media software applications do not support it.
There are many decisions to be made about HTML5 <audio> and <video> in the near future, and it will be interesting to see what codecs and formats are facilitated in the final recommendation.
In the meantime, we can try to support all browsers by making video available in a variety of formats and by providing Flash video
as a fallback. Let's hope that a final decision is made, and that it is
not left to browser vendors to decide which formats to support, as that
would essentially render these new elements useless.
Again, we will see the <video> element in action later in new post.