Architecture for using Java bytecode for processing Digital Items

Abstract

The MPEG-21 Multimedia Framework aims to provide an end-to-end framework for transparent and universal access to media content. It defines mechanisms to represent, process and exchange aggregate media objects, called Digital Items.

One of the main requirements in MPEG-21 is to devise a mechanism for making Digital Items dynamic, by allowing program code to be packaged along with them. This executable code consists of operations that are used to process the

Digital Item. The design of this mechanism is categorized into three parts: a specification to express and package these processing operations, an engine on the platform to execute the processing operations, and base APIs on the platform that will assist in implementing these processing operations.

This thesis proposes a solution that uses Java for expressing Digital Item processing operations. Also as a part of this solution, it proposes adapting the MPEG-J specification to define an engine for the execution of the the Java based processing operations. The MPEG-J specification is an application engine specification for the execution of mobile Java code, defined in the MPEG-4 systems standard.

The MPEG-21 standards committee later realized that two kinds of processing operations should be supported: simple processing operations, and complex processing operations. It was decided that a scripting language should be used to support simple processing operations, while complex processing operations should be supported by a language like Java. The thesis adapts the first solution and proposes a second one to use Java to specify complex processing operations under the new architecture.

Apart from the specification of the two solutions, the thesis focusses on maintaining compatibility between the solutions and other parts of the MPEG-21 architecture. Other contributions of this thesis are the arguments for design choices made and recommendations presented to the MPEG-21 standards committee.