The annotation of continuous media

In principle, the presentation of continuous media is time-dependent. Examples of con­tinuous media are audio, video and graphics animation. This work is on the support for the annotation of continuous media, or the integration of voice comments with continuous- media documents like music and video clips. This application has strict synchronisation requirements, both with respect to the media involved and to user interaction. The applica­tion involves functions such as storage, management, control of GUIs, and of continuous- medium devices. These are realised by components which can be distributed across a network. New models and architectures have been defined to enable open distributed processing of applications, that is, distributed processing independent of operating systems. Abstractions are provided, which facilitate the development of applications, and these execute supported by platforms that implement such open architectures. These architectures have been based on an object-based client/server model. Our work aims at exploring object-orientation, open distributed processing and some characteristics of continuous media, through the development and use of the proposed application. The application is designed as a set of objects with well-defined functions and which interact between themselves. A distinguishing feature of the application is that it involves reusable components and mechanisms. For example, a mechanism, which enables components to control logical clocks and synchronise them, is incorporated in the application in response to its synchronisation requirements. The implementation is based on ANSAware, a platform that supports open distributed processing and allows distributed objects to bind to each other, to interact with one another, and to exhibit concurrent activities. The performance of the implementation is examined with respect to the application’s response to user requests. Response times of operations such as play, pause, etc., are measured, and the final results are better than a defined maximum tolerance. An analysis of the development approach is made with respect to support for real-time activities in the application, and to software reuse in the model proposed. This thesis concludes by reviewing the suitability of the object-oriented approach for the development of distributed continuous media applications.