Mining for Riches:A technical look at rich media platforms

Business platforms for application development have made significant evolutionary progress. Only recently has there been a truly open and portable platform implemented by multiple vendors for building business applications and services. But, these application platforms lack the ability to sufficiently handle today’s digital assets, such as product photographs, streaming audio and video, and marketing materials. Existing relational-database systems are often a company’s most important asset. But these systems don’t provide the structure required to efficiently manipulate and manage a wide variety of rich-media content.

In addition, new business models are evolving around the delivery of digital assets. These new ways of doing business require expanding application-integration capabilities for digital content. Existing media businesses are also realizing the value of managing and digitizing their assets in order to reduce costs and generate revenue. Current proprietary business platforms, however, do not meet these application requirements because there exists a fundamental difference between a relational asset and a digital asset.

Standards are emerging for the manipulation of digital assets, but they are complex and require specialized knowledge. What is needed is an open-software platform that understands the structural details of rich-media content and provides a straightforward, standards-based interface for application development. This article will describe the components needed to build a Rich Media platform.

Platform Requirements

The Rich Media Platform is an important part of an application environment. It does not redefine the world in terms of rich media, but integrates into the modern business platform. The platform is inclusive of existing applications and services. The Rich Media Platform needs to be part of a middleware architecture that enables and delivers applications that merge traditional business processing and modern rich-media elements. Middleware is the bridge between those with different domains of expertise. This difference is great between those who know media, such as file formats, color spaces, and stream encoding, and those who know business applications, such as database structures, messaging systems, and XML.

The architecture of the Rich Media Platform is based on a J2EE-compliant application server. The metadata framework is based on work in the digital-library community. It is a modernization and adaptation of the concept of the Repository Access Protocol (RAP), originally targeted at CORBA deployments. The core concepts are the digital object (or DO) and the disseminator. The digital object encapsulates both the metadata and the digital asset, the stream, which represents the raw digital asset. The disseminator is a unit of code capable of delivering the digital object in a particular format. Before describing details about digital object and the disseminator, an understanding of metadata standards is needed.

Metadata Standards

Meta information is being standardized in many vertical industries, just as XML standards have formed in most vertical industries. There are some common standards that apply to all domains.

Dublin Core metadata is used to supplement existing methods for searching and indexing Web-based metadata, regardless of whether the corresponding resource is an electronic document or a physical object. The Dublin Core Metadata Element Set (DCMES) was the first metadata standard delivered out of the DCMI, as IETF RFC 2413. DCMES provides a semantic vocabulary for describing the core information properties, such as description, creator, and date attributes.

The Warwick Framework describes an architecture for aggregating multiple sets of metadata. The Warwick Framework has two fundamental components, containers and packages. Packages are typed metadata sets. Containers are the unit for aggregating packages.

WebDAV stands for "Web-based Distributed Authoring and Versioning". It is a set of extensions to the HTTP protocol that allows users to collaboratively edit and manage files on remote web servers. The WebDAV specification (RFC 2518) provides a protocol that allows clients to perform remote web-content authoring. WebDAV provides two basic elements: properties and collections.

Properties are metadata about the resource being held. This metadata set is not specific, allowing each resource to have its own metadata definitions. Properties may be used to describe the asset as well as the state of the asset. There are two types of properties, described as live and dead. Live properties are enforced by the server, but can originate from the server or the client. Dead properties are stored on the server but the client enforces the semantics.

Collections are sets of digital assets contained within a hierarchical structure. Each digital asset and hierarchical folder contains an independent set of properties.

Solution overview
The Evolution of Rich Media
The Digital Object