An adaptive Lagrange multiplier determination method for rate-distortion optimisation in hybrid video codecs

TL;DR

This paper introduces an adaptive method for selecting Lagrange multipliers in rate-distortion optimization, improving video compression efficiency by tailoring parameters to content characteristics, with minimal added complexity.

Contribution

It presents a novel adaptive Lagrange multiplier estimation technique integrated into H.264 and HEVC codecs for better rate-distortion performance.

Findings

Up to 11% bitrate savings on tested sequences

Effective across various video contents

Minimal increase in computational complexity

Abstract

This paper describes an adaptive Lagrange multiplier determination method for rate-quality optimisation in video compression. Inspired by the experimental results of a Lagrange multiplier selection test, the presented approach adaptively estimates the optimum Lagrange multiplier for different video content, based on distortion statistics of recently encoded frames. The proposed algorithm has been fully integrated into both the H.264 and HEVC reference codecs, and is used in rate-distortion optimisation for encoding B frames. The results show promising (up to 11% on the sequences tested) overall bitrate savings, for a minimal increase in complexity, on various types of test content based on Bjontegaard delta measurements.