Decoding Energy Optimal Video Encoding for x265

Herglotz C, Bader M, Fischer K, Kaup A (2020)

Publication Language: English

Publication Type: Conference contribution, Conference Contribution

Publication year: 2020

Event location: Tampere FI

DOI: 10.1109/MMSP48831.2020.9287054


This paper presents optimal x265-encoder configurations and an enhanced optimization algorithm for minimizing the software decoding energy of HEVC-coded videos. We reach this goal with two contributions. First, we perform a detailed analysis on the influence of various encoder settings on the decoding energy. Second, we include an enhanced version of an algorithm called decoding-energy-rate-distortion optimization into x265, which we optimize for fast and efficient encoding. This algorithm introduces the estimated  decoding energy as an additional optimization criterion into the rate-distortion cost function. We evaluate the extended encoder in terms of bitrate, distortion, and decoding energy, where we perform energy  measurements to prove the superior energy efficiency. We find that the combination of the ‘fastdecoding’ tuning option of x265 with the enhanced decoding-energy-rate-distortion optimization leads to 27.2% and 26.0% of decoding energy savings for OpenHEVC and HM decoding, respectively. At the same time, compression efficiency losses of 4.31% and negligible decreases in encoder runtime of 0.39% can be observed.

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How to cite


Herglotz, C., Bader, M., Fischer, K., & Kaup, A. (2020). Decoding Energy Optimal Video Encoding for x265. In Proceedings of the IEEE 22nd Workshop on Multimedia Signal Processing (MMSP). Tampere, FI.


Herglotz, Christian, et al. "Decoding Energy Optimal Video Encoding for x265." Proceedings of the IEEE 22nd Workshop on Multimedia Signal Processing (MMSP), Tampere 2020.

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