Transcoding pattern generation for adaptation of digital items containing multiple media streams in ubiquitous environment

Digital item adaptation (DIA) is one of main parts in MPEG21. The goal of the DIA is to achieve interoperable transparent access to multimedia contents by shielding users from network and terminal installation, management and implementation issues. In general, a digital item consists of multiple discrete or continuous media and adaptation process is to be applied to one of its multiple media. Therefore in the process of adapting the given digital item, the transcoding order of its media has great impact on the adaptation performance because the adaptation process may stop at the point of satisfying a adaptation QoS(Quality of Services). In order to reduce the transcoding time which result in reducing the initial delay time, we propose a pattern based transcoding model for DIA. Because the performance of the model is dependent on the pattern, we also suggest a EPOB based pattern generation method. Finally a sample pattern was suggested based on the experimental results of the method.