Evaluation of Hardware-based Video Encoders on Modern GPUs for UHD Live-Streaming

TL;DR

This paper evaluates the performance of modern GPU hardware encoders for UHD live-streaming, comparing their rate-distortion efficiency, speed, and power consumption against software encoders across various hardware generations and codecs.

Contribution

It provides a comprehensive comparison of hardware and software video encoders on GPUs and mobile SoCs, highlighting their RD performance, encoding speed, and power efficiency for high-resolution live streaming.

Findings

Hardware encoders match software RD performance in real-time scenarios.

Encoding speed has improved in newer hardware generations.

Negligible RD performance gains between recent hardware generations.

Abstract

Many GPUs have incorporated hardware-accelerated video encoders, which allow video encoding tasks to be offloaded from the main CPU and provide higher power efficiency. Over the years, many new video codecs such as H.265/HEVC, VP9, and AV1 were added to the latest GPU boards. Recently, the rise of live video content such as VTuber, game live-streaming, and live event broadcasts, drives the demand for high-efficiency hardware encoders in the GPUs to tackle these real-time video encoding tasks, especially at higher resolutions such as 4K/8K UHD. In this paper, RD performance, encoding speed, as well as power consumption of hardware encoders in several generations of NVIDIA, Intel GPUs as well as Qualcomm Snapdragon Mobile SoCs were evaluated and compared to the software counterparts, including the latest H.266/VVC codec, using several metrics including PSNR, SSIM, and machine-learning based VMAF. The results show that modern GPU hardware encoders can match the RD performance of software encoders in real-time encoding scenarios, and while encoding speed increased in newer hardware, there is mostly negligible RD performance improvement between hardware generations. Finally, the bitrate required for each hardware encoder to match YouTube transcoding quality was also calculated.