State of Media Accessibility in HTML5

Today I gave a talk at the Open Video Conference about the state of the specifications in HTML5 for media accessibility.

To be clear: at this exact moment, there is no actual specification text in the W3C version of HTML5 for media accessibility. There is, however, some text in the WHATWG version, providing a framework for text-based alternative content. Other alternative content still requires new specification text. Finally, there is no implementation in any browser yet for media accessibility, but we are getting closer. As browser vendors are moving towards implementing support for the WHATWG specifications of the <track> element, the TimedTrack JavaScript API, and the WebSRT format, video sites can also experiment with the provided specifications and contribute feedback to improve the specifications.

Attached are my slides from today’s talk. I went through some of the key requirements of accessibility users and showed how they are being met by the new specifications (in green) or could be met with some still-to-be-developed specifications (in blue). Note that the talk and slides focus on accessibility needs, but the developed technologies will be useful far beyond just accessibility needs and will also help satisfy other needs, such as the needs of internationalization (through subtitles), of exposing multitrack audio/video (through the JavaScript API), of providing timed metadata (through WebSRT), or even of supporting Karaoke (through WebSRT). In the tables on the last two pages I summarize the gaps in the specifications where we will be working on next and also show what is already possible with given specifications.

7 thoughts on “State of Media Accessibility in HTML5

  1. @antistress: what is used on for providing subtitles is a hand-crafted JavaScript. This is the way in which you can provide captions and subtitles today. However, it is not standardized and therefore everyone will provide it differently, making it impossible for search engines to build on it and index it. Once the HTML5 specification is adopted by browsers and Websites, search engines can build on it and start indexing it, so you will be able to search into video fragments.

  2. I was wondering if JavaScript was really essential to have that kind of experience : wouldn’t it be possible to only use HTML ? I’d like to think that a web is still possible using only HTML (& CSS). Some people see some security concerns in JavaScript (look at NoScript Firefox add-on for instance).

  3. @antistress No, I am not aware of any browsers having implemented support for track yet. They may be working on it.

    It seems though that Safari5 supports mpeg4 files that have encapsulated caption tracks. That’s new and a first step towards getting in-band caption support.

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