An Empirical Study of Reducing AV1 Decoder Complexity and Energy Consumption via Encoder Parameter Tuning
Vibhoothi Vibhoothi, Julien Zouein, Shanker Shreejith, Jean-Baptiste Kempf, Anil Kokaram
TL;DR
This study addresses the high decoding energy of AV1 on battery-powered devices by evaluating encoder-side parameter tuning in libaom-av1 and SVT-AV1. It employs a tool-off analysis and system-level energy measurements using RAPL and Intel SoC Watch to quantify trade-offs between decoding complexity, energy consumption, and compression quality. Key findings show that disabling tools like CDEF in libaom-av1 or using SVT-AV1's fast-decode preset can reduce decoding cycles by about 10–24% with minimal perceptual quality loss, while system-level measurements reveal nuanced energy effects not captured by CPU metrics alone. The work provides actionable guidelines for content providers to generate energy-efficient AV1 streams and highlights the importance of holistic energy profiling, with future work extending to ARM/mobile platforms and further multi-parameter optimization including tiling.
Abstract
The widespread adoption of advanced video codecs such as AV1 is often hindered by their high decoding complexity, posing a challenge for battery-constrained devices. While encoders can be configured to produce bitstreams that are decoder-friendly, estimating the decoding complexity and energy overhead for a given video is non-trivial. In this study, we systematically analyse the impact of disabling various coding tools and adjusting coding parameters in two AV1 encoders, libaom-av1 and SVT-AV1. Using system-level energy measurement tools like RAPL (Running Average Power Limit), Intel SoC Watch (integrated with VTune profiler), we quantify the resulting trade-offs between decoding complexity, energy consumption, and compression efficiency for decoding a bitstream. Our results demonstrate that specific encoder configurations can substantially reduce decoding complexity with minimal perceptual quality degradation. For libaom-av1, disabling CDEF, an in-loop filter gives us a mean reduction in decoding cycles by 10%. For SVT-AV1, using the in-built, fast-decode=2 preset achieves a more substantial 24% reduction in decoding cycles. These findings provide strategies for content providers to lower the energy footprint of AV1 video streaming.
