Comparison of Compression Efficiency between HEVC/H.265, VP9 and AV1 based on Subjective Quality Assessments

Abstract

Abstract-The growing requirements for broadcasting and streaming of high quality video continue to trigger demands for codecs with higher compression efficiency. AV1 is the most recent open and royalty free video coding specification developed by Alliance for Open Media (AOMedia) with a declared ambition of becoming the most popular next generation video coding standard. Primary alternatives to AV1 are the VP9 and the HEVC/H.265 which are currently among the most popular and widespread video codecs used in applications. VP9 is also a royalty free and open specification similar to AV1, while HEVC/H.265 requires specific licensing terms for its use in commercial products and services. In this paper, we compare AV1 to VP9 and HEVC/H.265 from rate distortion point of view in a broadcasting use case scenario. Mutual comparison is performed by means of subjective evaluations carried out in a controlled environment using HD video content with typical bitrates ranging from low to high, corresponding to very low up to completely transparent quality. We then proceed with an in-depth analysis of advantages and drawbacks of each codec for specific types of content and compare the subjective comparisons and conclusions to those obtained by others in the state of the art as well to those measured by means of objective metrics such as PSNR.

A Subjective Comparison of AV1 and HEVC for Adaptive Video Streaming

“…We consider two codecs: AV1 and HEVC, selected because they are generally considered to be competing technologies with similar performance [3,6,8,11,13,22]. Each codec was configured such that the structural delay was limited to 16 frames (i.e.…”

“…These comparisons were however based solely on objective metrics -none of them report subjective results. In contrast, recent subjective comparisons between AV1 and HEVC [11][12][13] do not consider the impact of the adaptive streaming environment.…”

An Overview of Coding Tools in AV1: the First Video Codec from the Alliance for Open Media

“…Firstly, when random access mode is used for HEVC and VVC codecs, the counterpart mode of libaom is two-pass coding with non-zero (19 is recommended) lagin-frames, rather than 1-pass mode and zero lag-in-frames which will disable all bi-directional prediction tools as in Refs. [10][11][12]. Secondly, as constant quality mode is usually used for HEVC and VVC codecs in the comparison, to match the setting, libaom needs to choose such mode as well by specifying end-usage = q and passing in the QP (cq-level), rather than either using libaom in vbr mode to match the rates produced by other codecs [13], or manually restraining libaom's QP by setting min-q and max-q [14].…”

Objective Quality Assessment of Multi-Resolution Video based on H.264/AVC and H.265/HEVC Encoding

“…This triggers an increasing need for video compression. Thus, one of the most critical needs in the realm of video coding is to increase efficiency at lower costs [5].…”

“…H.264 is considered a mature standard [11] and is widely used for various applications both real-time and non-real-time [12] [13]. Whereas H.265 is an evolution of its predecessor with the target of 50% bitrate saving but has similar quality encoding results [5] [8].…”