In universal media access (UMA) environment, because of the heterogeneous networks and terminals, flexible video adaptation, that is performed according to the network conditions and terminal capabilities as well as user preferences, is required to maximize consumer experience and ensure Quality of Service (QoS). MPEG-21 Digital Item Adaptation (DIA) support an interoperable framework for effective and efficient video adaptation. Among MPEG-21 DIA tools, utility function that describes the relations among the feasible adaptation operation, resource constraint, and utility plays the most important role in adaptation process because the optimal adaptation operation is decided among the feasible adaptation operations with given constraints. Therefore, in this paper, the overall concept of MEPG-21 DIA based adaptation framework and formulation of utility function are presented. In addition, the feasibility of the adaptation framework is presented by applying it to a few use cases for generating utility function and applications to specific adaptation scenarios involving nonscalable and scalable video.