Encoding Complexity Analysis and Reduction for a Practically-Oriented VVC Encoder Implementation

Abstract

The latest international Versatile Video Coding (VVC) standard was finalized in July 2020 by the Joint Video Experts Team (JVET) from ITU-T and ISO/IEC. Compared to the High Efficiency Video Coding (HEVC) standard, VVC offers up to 50% of bitrate savings. However, the encoder runtime of the reference software increases tenfold compared to the HEVC equivalent. This paper shows that VVC coding tools which do not consume much of the reference encoder time can have prohibitive computational cost for practical encoders, such as VVenC. VVenC is an optimized open-source real-world implementation with high relevance for practical applications. After analyzing the encoding tools in VTM and VVenC, Symmetric Motion Vector Difference (SMVD) was identified as one of the tools whose efficiency-complexity trade-off may be unfavorable for practical applications. For that reason, two complexity reduction methods for the SMVD search are proposed in this paper. The experimental evaluation on VVenC encoder at an optimized operation point confirms the SMVD encoding runtime reduction by over 72%, with minimal impact on the encoding efficiency.