ABSTRACT
This chapter addresses several transcoding aspects related to the distribution of digital content. The universal multimedia access (UMA) concept is an important topic for the content distribution. The primary function of UMA services is to provide the best quality of service (QoS) or user experience by either selecting/adapting the content format to meet the playback environment, or adapting the content playback environment to accommodate the content. After reviewing the concept of UMA, we describe how the concept of UMA relates to the emerging MPEG standard, digital item adaptation (DIA), which is Part 7 of the MPEG-21 standard. An update on the standards activity in this area is presented. Finally, we discuss the impact that DIA will have on transcoding strategies and analyze some areas of future research.
