Techniques for authoring multimedia documents: Scheduling and flow control.

Abstract

The area of multimedia applications keeps growing as more media become accessible and affordable on various computer platforms. Through the use of multiple information channels, more effective and expressive communication among people using computers is possible. However, due to the lack of a systematic authoring environment, multimedia documents are difficult to construct and their production is unnecessarily constrained in the ways that temporal and spatial relationships within the document can be expressed, and in the ways which user interactions can be employed. In this dissertation, a number of techniques to enhance the multimedia authoring environment are presented. A hierarchical framework is provided to form the basic multimedia document structure and to support various media materials uniformly, including regular media as well as user interactions. Based on this framework a set of algorithms for low-level analysis and synthesis are developed to support high level authoring tools. Error checking such as resource conflict detection and resolution, as well as better understanding of a multimedia document therefore become possible. A number of flow control primitives have also been identified to support flexible user interactivity. Finally, mechanisms to realize a novel multimedia authoring approach, the walk-through paradigm, are developed. All these techniques are implemented and tested in a multimedia authoring prototype environment following object-oriented design principles. Together, these techniques support more interesting multimedia documents, better authoring aids and more friendly authoring environment. Better user interaction is possible in multimedia documents with flexible scheduling and presentation flow control. Interactively analyzing and modifying the document provides useful authoring support, and the walk-through mechanism supports an easy-to-use authoring tool.