Intra Encoding Complexity Control with a Time-Cost Model for Versatile Video Coding

TL;DR

This paper introduces a novel intra encoding complexity control scheme for VVC using a Time-Cost model, enabling precise complexity management with minimal rate-distortion impact.

Contribution

It proposes a Time-PlanarCost model for CTU encoding time estimation and a framework for accurate picture-level complexity control in VVC.

Findings

Complexity error converges under 3.21%

Achieves significant time savings with minimal RD loss

Effective for challenging intra coding scenarios

Abstract

For the latest video coding standard Versatile Video Coding (VVC), the encoding complexity is much higher than previous video coding standards to achieve a better coding efficiency, especially for intra coding. The complexity becomes a major barrier of its deployment and use. Even with many fast encoding algorithms, it is still practically important to control the encoding complexity to a given level. Inspired by rate control algorithms, we propose a scheme to precisely control the intra encoding complexity of VVC. In the proposed scheme, a Time-PlanarCost (viz. Time-Cost, or T-C) model is utilized for CTU encoding time estimation. By combining a set of predefined parameters and the T-C model, CTU-level complexity can be roughly controlled. Then to achieve a precise picture-level complexity control, a framework is constructed including uneven complexity pre-allocation, preset selection and feedback. Experimental results show that, for the challenging intra coding scenario, the complexity error quickly converges to under 3.21%, while keeping a reasonable time saving and rate-distortion (RD) performance. This proves the efficiency of the proposed methods.