Requantization transcoding for reduced-complexity H.264/AVC video coding applications

Video adaptation constitutes an important challenge in present day video applications. In many video adaptation scenarios, not only the bandwidth availability, but also the computational power will be limited. One such example is video conferencing. In this case, conferees have different devices at their disposal, and participate under different network circumstances. In order to shape the bitstreams to the varying networks, transcoding is often used as a fast and efficient technique for bitrate reduction. In this paper, we discuss H.264/AVC coding tools, their complexity and influence on rate-distortion performance, and how they are affected by transcoding. We show that by eliminating advanced coding tools, the complexity of the overall architecture is severely reduced, while the quality loss remains limited, in particular for low resolutions and low bitrates