Lloyd-Max quantization-based priority index assignment for the scalable extension of H.264/AVC

A fast priority index (PID) assignment algorithm is developed for the MGS (Medium Grain Scalability) packets in the scalable extension of the H.264/AVC. The contributions of the paper are threefold. First, we formulate the index assignment problem as the quantization of the rate-distortion (R-D) slopes of MGS packets, and use the Lloyd-Max algorithm to find the optimal solution. The slope quantization index of a packet is used as its PID. The complexity of our method is much lower than existing method. Secondly, the quantization-based PIDs facilitate the comparisons of packets from different video streams. Video multiplexing results show that the overall PSNR can be improved up to 1 dB. Finally, we propose some real-time and adaptive implementations of the proposed method, which have the same performance as the offline method.