Simplified Level Decision in Rate-distortion Optimized Quanitzation
Motong Xu, Thuong Nguyen Canh, Byeungwoo Jeon · 2019
Rate-distortion optimized quantization (RDOQ) provides a considerable compression improvement in High efficiency video coding (HEVC) but with high computational complexity. This paper addresses a simplified RDOQ scheme for HEVC encoder by developing a level estimation (LE) bypass scheme based on the coefficient group location and transform coefficient value. Early termination of last nonzero coefficient search is also investigated to further save the number of rate-distortion cost calculation. Its experimental result shows that our proposed simplified level decision scheme can save the total quantization time by 5.11% and 4.08% with BDBR loss of just 0.02% and 0.01%, respectively under all intra and random access coding configurations.