HTML5 - A Game Changer?

HTML (HyperText Markup Language) is the language of the code that sits behind every web page displayed by a browser. You find it on any web page by right-clicking your mouse and selecting View Page Source. Compared to HTML4 which was introduced in 1997, HTML5 introduces many new interesting elements. For example, the HTML5 dictionary includes “canvas” which allows inserting moving graphics that can be used in games and animations.

The HTML5 specification enables the browser to store 1000 times more data than is currently possible, so that it is possible to use web pages even when there is no connection to the Internet. For broadcasters and content providers, the most useful feature is a new capability for the native support of audio and video playback.

HTML5 is not yet fully developed and still lacks a support for many features that are critically important for the content provider: adaptive streaming, digital rights management, advertising and monetisation. In spite of that, it has already been implemented by all major browsers, e.g., Mozilla Firefox, Apple Safari, Google Chrome, Opera and lately Microsoft Internet Explorer 9.

Before the advent of HTML5, in order to get video to play, websites added proprietary programmes (e.g., Adobe Flash and Microsoft Silverlight) and required the users to download “plug-ins” to play them. That made websites more complex and dependent on a plug-in presence in the client device.

HTML5 provides a new <video> tag to play video directly (“natively”) in the browser itself, therefore no third party plug-in is required. Contrary to a plug-in where video is locked away and trapped in a black box, the <video> element can be manipulated flexibly: it can be styled with CSS, resized on hover using CSS transition, it can be tweaked and redisplayed onto <canvas> with JavaScript, etc.

The <video> tag itself is codec agnostic and leaves the browser developer open to support whatever codec they wish. This leaves the door open to the situation where each browser could use a codec of their choice. This could potentially lead to a market fragmentation and indeed to reverting back to the use of proprietary plug-ins. The table below shows which video codecs (embedded in the appropriate containers) are currently supported by the most recent browsers.

Today H.264 is the most widely used video codec in digital broadcasting. In the internet several codecs are being used, the most popular ones being H.264 and WebM/VP8. In today’s convergent environments where the IT, consumer electronics (including mobile) and broadcast worlds are coming together and the borderline between them is blurring, it would be advantageous to consider common audio and video coding for the internet and broadcasting.

Not surprising, broadcasters prefer using H.264 not only for broadcasting but also for internet distribution of video files and streams. The H.264 license issues have been successfully resolved. MPEG LA announced in August 2010 that “H.264 will be royalty-free forever so long as video encoded with the standard is free to end users and delivered via the Internet”. This means that no royalties are required for the H.264 web videos that are delivered free of charge.

However, Google recently decided to discontinue supporting H.264, as it only intends to use “open source, licence-free” codecs such as WebM/VP8. Many experts however, fear that the unresolved WebM “submarine” patent issues might later hit those who have implemented this codec. Google’s decision may force the content providers wishing to target the most popular browsers to produce two video versions, one in H.264 and the other in VP8. As things stand today, Apple and Microsoft will probably continue to support the H.264 codec, whereas Mozilla Firefox, Opera and now Google are likely to support merely WebM/VP8. It is unlikely that these two camps will ever agree on a common approach.

Although some optimists believe that HTML5 signifies the web’s rebirth, many sceptics share the opinion that HTML5 may rise or fall depending on whether or not the browsers are able to reach a consensus on a common native video and audio codec. Unfortunately, the prospects of reaching such consensus seem to be meagre.

By Franc Kozamernik, EBU Tech-i