Energy consumption evaluation of H.264 and HEVC video encoders in high-resolution live streaming

Green computing and energy efficiency has become an important issue in today's rapidly growing multimedia transmission. Meanwhile users want high-quality content to be viewed anywhere, content producers must think alternatives for cutting expenses in the server. Usually multiple sub-streams from the original video feed are needed for clients with unique device characteristics, which can notably load the video encoding server leading also to increased energy consumption. Furthermore, social sharing applications using live video streaming can consume battery notably, which also drives developing energy-efficient video coding solutions. Therefore, it is essential to find ways for optimizing and selecting the proper tools for energy-efficient content production already in the server. In this paper, we evaluate the energy and power consumption for the existing top-rated open source video encoders in proportion to video quality and bit rate. The selected video coding formats include current dominant H.264 Advanced Video Coding (H.264/AVC), latest standard High Efficiency Video Coding (HEVC) and Google's royalty free VP9. The results show that the selected H.264 encoder (x264) has the lowest energy consumption, but the worst compression efficiency. On the contrast, x265 for HEVC has the best compression efficiency, but suffers from increased energy consumption. For our experiments, VP9 provides the best trade-off between compression efficiency and energy consumption.