Research on MPEG-21 digital item adaptation technology

MPEG-21 digital item adaptation framework and format-independent media resource adaptation mechanism were studied. The perceived motion energy (PME) model was incorporated into the proposed H.264/AVC video adaptation system based on MPEG-21 DIA framework, the adaptation engine for multimedia resources was designed. An adaptation decision algorithm was also presented which was realized by retaining most of the higher quality layers, and dropping lower quality layers as far as possible. The experiment results showed that most of the video sequences, with an average up to 50%-60% of dropped frames, will get an acceptable grading (fair), resulting in a corresponding reduction of an average of 24% in the transmitting bit rate. The proposed system not only ensures the viewers' perceived qualities as high as possible but also realizes format-independent video adaptation mechanism and enhances the flexibility and scalability of multimedia adaptation system.