A framework for MPEG-21 DIA based adaptation and perceptual encryption of H.264 video

A ubiquitous computing concept permits end users to have access to multimedia and digital content anywhere, anytime and in any way they want. As a consequence, the importance of resource customization according to user preferences and device requirements set the primary challenge towards seamless access. Moreover, once a suitable customization approach has been decided (e.g. adaptation), deploying it in the existing network requires a generic and widely accepted standard applied to the process. With the advancement of time, performing encryption in the compressed domain should also be taken care of not only for serving sensitive digital contents but also for offering security as an embedded feature of the adaptation practice to ensure digital right management and confidentiality. In this paper, we present an architecture for temporal adaptation of ITU-T H.264 video conforming to ISO/IEC MPEG-21 DIA. In addition, we present a perceptual encryption scheme that is integrated in the system for video encryption. The framework enables video bitstreams to be adapted and encrypted in the compressed domain, eliminating cascaded adaptation (i.e. decoding - adaptation - encoding). The encryption framework is applied on the adapted video content, which reduces computational overhead compared to that on the original content. A prototype, based on the proposed architecture and experimental evaluations of the system as well as its performance supporting the architecture are also presented.