RDO Candidate Selection for Maximizing Coding Efficiency in a Practical HEVC Encoder
Joose Sainio, Alexandre Mercat, Jarno Vanne
Abstract
High Efficiency Video Coding (HEVC) creates the conditions for economic video transmission and storage but making most of its compression potential calls for effective rate-distortion optimization (RDO) techniques in practical HEVC encoders. This paper explores the effectiveness of the following universally applicable RDO techniques: 1) rough mode decision for intra RDO candidate selection; 2) number of intra and inter RDO search candidates; and 3) accurate bit cost estimation in entropy coding. All these techniques are implemented into Kvazaar open-source HEVC encoder and altogether they improve the coding efficiency of Kvazaar veryslow preset by 5.7%, 4.0%, and 7.1% with PSNR, SSIM, and VMAF quality metrics, respectively. Even though the proposed techniques reduce the coding speed of Kvazaar to 0.64×, Kvazaar is still, on average, 2.16× as fast as the x265 encoder and attains 12.4%, 22.3%, and 4.7% better coding gain for the same PSNR, SSIM, and VMAF quality, respectively. These results let us conclude that Kvazaar is currently the leading practical open-source solution for high-quality HEVC encoding.
BibTeX
@inproceedings{icassp2023_rdocandidatesele,
title = {RDO Candidate Selection for Maximizing Coding Efficiency in a Practical HEVC Encoder},
author = {Joose Sainio and Alexandre Mercat and Jarno Vanne},
booktitle = {ICASSP 2023},
year = {2023}
}