W3C and the Entertainment Sector

The role of W3C is to establish recommendations for generic technologies on the World Wide Web that operate between the underlying transport layer and the applications specific to individual industrial sectors. Practitioners active in industrial sectors will need to establish those applications, but they also need to ensure that the generic technology on which they are built provides them with the opportunities they require and does not constrain them so much as to prevent them from producing what they need for their own industrial sector. To do this practitioners in industrial sectors other than information technology need to be aware of and involved in the development of future recommendations at the generic level that W3C operates. Here are described some of the W3C technologies on which applications in the entertainment sector are based. The information technology applications in the entertainment sector where W3C have a role address content management and re-use as well as protection of content; that is the XML technologies that allow content to be written once in a device independent way and then re-used many times for presentation on different devices in textual, graphic, auditory or synchronised multimedia presentations, as well as the protection of that content through encryption, keys and rights management.

Device Independence

The main advantage of XML is that it separates content from presentation. This allows reuse of content. In addition, the content can be formatted using several XML based markup languages, e.g., Synchronized Multimedia Integration Language (SMIL), eXtensible Stylesheet Language Formatting Objects (XSL FO), Scalable Vector Graphics (SVG), and eXtensible HyperText Markup Language (XHTML). XML based content can be transformed using XSL into these formats. This is convenient, for example, in multichannel publishing. The original content is transformed to presentations suitable for different kinds of end user terminals including personal computers, Personal Digital Assistants (PDA), and digital television Set-Top Boxes (STB). This is not possible with HTML, since the HTML file contains instructions for presentation, which is usually designed only for personal computers. In addition to transforming content for different devices, the content can also be tailored for different user profiles. This, so called personalization, requires that user profile are transferred from client to the server. For example, the Composite Capability / Preference Profile (CC/PP) protocol has been proposed for this purpose. The CC/PP Working Group is developing an RDF-based framework for the management of device profile information. CC/PP is a user-side device hardware, software and user preferences profile written in Resource Description Framework (RDF), W3C's language for modelling metadata There are significant efforts to integrate Web technologies into various devices (e.g., mobile, TV sets) other than the traditional Web access equipment such as PCs. However, we are faced with the possibility that services for those devices may not interoperate with each other or with the existing Web. That would not only cause fragmentation of the Web space, but also make Web device independent authoring impossible. To overcome this, the W3C Device Independence Activity is developing various Principles, Authoring Challenges, Overviews of Delivery Context, and Requirements for Device Independence.

Graphical presentation - SVG

SVG is a language for describing two-dimensional graphics in XML. SVG allows for three types of graphic objects: vector graphic shapes (e.g., paths consisting of straight lines and curves), images and text. Graphical objects can be grouped, styled, transformed and composed into previously rendered objects. Text can be in any XML namespace suitable to the application, which enhances searchability and accessibility of the SVG graphics. The feature set includes nested transformations, clipping paths, alpha masks, filter effects, template objects and extensibility. SVG drawings can be dynamic and interactive. The Document Object Model (DOM) for SVG, which includes the full XML DOM, allows for straightforward and efficient vector graphics animation via scripting. A rich set of event handlers such as onmouseover and onclick can be assigned to any SVG graphical object. Because of its compatibility and leveraging of other Web standards, features like scripting can be done on SVG elements and other XML elements from different namespaces simultaneously within the same Web page.

Multimedia Presentation - SMIL

W3C does not set the standards for transport protocols for streaming video or audio over the Internet (e.g. RTP, RTSP) - these are set by the Internet Engineering Task Force (IETF). W3C's role has been to standardise the integration language to synchronise together audio, video, still images and text and turn them into a single presentation. The SMIL language does this, allowing the construction of multimedia presentations from media assets held at locations distributed around the web, not necessarily all owned by one organisation.

Music Notation

As an application rather than a generic technology W3C does not itself develop mark-up languages for music, however several other bodies have done so including Music Encoding Initiative (MEI) and Music XML, Music Markup Language each of which provide XML based languages to represent Western music notation as used from the 18th to mid 20th centuries.

Encryption and Digital Key Management

W3C in conjunction with the IETFis developing series of security standards for XML. These include a process for encrypting/decrypting digital content (including XML documents and portions thereof) and an XML syntax used to represent the encrypted content and information that enables an intended recipient to decrypt it - XML Encryption. To undertake such XML encryption requires the transmission of the keys used in encryption. Therefore W3C is also developing a specification of XML application/protocol that allows a simple client to obtain key information (values, certificates, management or trust data) from a web service. This specification will be based on the XML Key Management Specification (XKMS). XKMS specifies protocols for distributing and registering public keys, suitable for use in conjunction with the standards for XML Signature and XML encryption. The XML Key Management Specification (XKMS) comprises two parts -- the XML Key Information Service Specification (X-KISS) and the XML Key Registration Service Specification (X-KRSS).

Digital Rights Management (DRM)

Building on the generic technologies for encryption and digital key management using XML are several applications addressing digital rights management developed by bodies other than W3C which include the Open Digital Rights Language (ODRL), the Extensible Rights Markup Language (XrML), Digital Property Rights language (DPRL), Extensible Media Commerce Language (XMCL), Extensible Access Control Markup Language (XACML), MPEG Rights Expression Language and Data Dictionary. The lack of digital rights management has been the chief stumbling block for open standards resulting in a chaotic and not always workable mix of technology, policy, law and business practice. In this environment, any list is incomplete, but it is essential if you are to be active in DRM to understand the underlying technologies from W3C outlined above.

Further Information