Rate-Quality or Energy-Quality Pareto Fronts for Adaptive Video Streaming?
Angeliki Katsenou, Xinyi Wang, Daniel Schien, David Bull
TL;DR
The paper challenges rate-only optimizations in adaptive video streaming by introducing energy-quality (EQ) curves and corresponding Pareto fronts, alongside conventional rate-quality (RQ) analysis. It builds three-resolution decoding-energy and VMAF-based quality spaces, derives rate-quality-energy (RQE) and energy-quality (EQ) Pareto fronts via Akima interpolation, and constructs both rate-driven and quality-driven ladders from these fronts. Empirical results on YouTube-UGC using x265 show decoding energy reductions of up to ~31% at comparable QoE, with quality-driven ladders achieving additional bitrate and energy savings. The work highlights the potential of energy-aware ladder design to improve streaming efficiency and motivates future work on including display power and carbon emissions and refining perceived-quality sufficiency.
Abstract
Adaptive video streaming is a key enabler for optimising the delivery of offline encoded video content. The research focus to date has been on optimisation, based solely on rate-quality curves. This paper adds an additional dimension, the energy expenditure, and explores construction of bitrate ladders based on decoding energy-quality curves rather than the conventional rate-quality curves. Pareto fronts are extracted from the rate-quality and energy-quality spaces to select optimal points. Bitrate ladders are constructed from these points using conventional rate-based rules together with a novel quality-based approach. Evaluation on a subset of YouTube-UGC videos encoded with x.265 shows that the energy-quality ladders reduce energy requirements by 28-31% on average at the cost of slightly higher bitrates. The results indicate that optimising based on energy-quality curves rather than rate-quality curves and using quality levels to create the rungs could potentially improve energy efficiency for a comparable quality of experience.
