Performance Comparison of Emerging EVC and VVC Video Coding Standards with HEVC and AV1

Abstract

<i>The recent dramatic increase in video content consumption requires efficient video coding standards, which is specifically true for ultrahigh-definition (UltraHD) resolutions, such as 4K and 8K (i.e., 3840&#x00D7;2160 or 7680&#x00D7;4320 resolutions in terms of luma samples, respectively). The well-known high-efficiency video coding (HEVC) [H.265/Moving Pictures Expert Group (MPEG)-H] standard was approved in 2013. Although HEVC provides approximately 50&#x0025; coding gain compared to its predecessor advanced video coding (AVC) (H.264/MPEG-4), its adoption is still relatively slow. In addition, larger bitrate savings than those provided by HEVC are currently in demand. At the same time, work on the versatile video coding (VVC) and essential video coding (EVC) standards started in 2018. After intensive development efforts that continued for two and a half years, these two video coding standards have been recently finalized. VVC (H.266/MPEG-I) was developed jointly by the MPEG and the International Telecommunication Union-Telecommunication (ITU-T) Video Coding Experts Group (VCEG). On the other hand, EVC (MPEG-5) is an MPEG-only effort. In this paper, we compare the performance of EVC and VVC, in terms of both coding gains and computational complexity, to their predecessor&#x2014;the HEVC video coding standard. In addition, given the growing popularity of the AV1 video codec, which was recently developed by the Alliance for Open Media (AOM), we also include AV1 as an alternative baseline and provide corresponding comparison results. According to the experimental results, which have been carried out in a constant bitrate (CBR) mode, EVC provides about 30&#x0025; bitrate savings compared to HEVC for encoding 4K/2160p entertainment content (such as VoD) in terms of Bj&#x00F8;ntegaard-delta bitrate (BD-BR) peak-signal-to-noise ratio (PSNR)_YUV, while introducing an encoding computational complexity increase of approximately five times. VVC provides larger bitrate savings of about 40&#x0025; at a price of a significant encoding computational complexity increase of more than nine times. When the performance of HEVC CBR encoding (i.e., with the rate control disabled) was compared to that of AV1 VBR encoding (i.e., with the rate control enabled), it was found that AV1 provides bitrate savings of about 20&#x0025; compared to HEVC for encoding 4K/2160p video sequences, as a tradeoff of an encoding computational complexity increase by a factor of approximately four. The authors find both EVC and VVC to be very promising successors to HEVC in terms of coding gains and computational complexity, but the jury is still out on the speed of their adoption</i>.