Utilising Macroblock SKIP Mode Information to Accelerate Cropping of an H.264/AVC Encoded Video Sequence for User Centric Content Adaptation

Constraints on the storage, transmission and consumption deter seamless access to massive supply of multimedia contents readily available for consumers. Consequently, universal multimedia access (UMA) still remains a challenging objective. Context based digital item adaptation (DIA) is seen as a key technology to realise UMA. Scalability options in modern video coding standards provide inherent support for video adaptation. However, it is unlikely that all digital items (DIs) are coded with required scalability options. User centric adaptation adds even more strain on scalability. One such application is to deliver a user defined region of interest (ROI) from a high resolution video to a low resolution terminal. Transcoding is still the solution for such adaptation scenarios. This paper discusses a framework to accomplish such adaptation in H.264 coded video and demonstrates the effectiveness of utilising SKIP mode macroblocks to reduce the transcoding complexity.