Efficient binary representation of delta Quantization Parameter for High Efficiency Video Coding

This paper proposes an efficient binary representation of delta Quantization Parameter (QP) for High Efficiency Video Coding (HEVC). Video encoders adapt QPs of coding blocks for visual quality optimization and rate control. Although they send only delta QPs (dQPs) obtained by causal prediction, the side information overhead is expensive. Therefore the HEVC design necessitates an efficient dQP coding. The proposed scheme converts a dQP to a binary string in which the first and second bins indicate the significance and sign of the dQP respectively and the rest represents the magnitude minus 1. Furthermore, it detects and truncates redundant bins in the binary strings by using the sign and an admissible dQP range. Thus it reduces the length of dQP binary strings and improves dQP coding efficiency. Simulation results using HEVC reference software demonstrate that the proposed scheme improves the dQP coding efficiency by 6% while reducing its bin rates by 25%.