Fast partitioning strategies for VVC and their implementation in an Open Optimized Encoder
Adam Wieckowski, Benjamin A. Bross, Detlev Marpe · 2021
In July 2020 the new video coding standard Versatile Video Coding (VVC) was released. VVC delivers bitrate savings of up to 50% relative to its predecessor High Efficiency Video Coding (HEVC) without compromising subjective quality. It has been designed for a broad range of applications and input material ranging from standard dynamic range to high dynamic range camera-captured content, screen content, and immersive applications. One of the key technologies included in the new standard is the flexible block partitioning using a quad-tree with multi-type tree structures (QT+MTT). Based on the VVC test model VTM, the VVenC project provides an open optimized VVC encoder. VVenC inherits and utilizes all of VTMs in-built partitioning search strategies. The QT+MTT partitioning search still poses a challenge for fast encoder implementations. After defining alternative low-depth partitioning configurations to VTM, it was observed that the initial search algorithm performs less optimal. We analyze and propose in this paper a set of additional fast search strategies for partitioning within VVenC, optimized for low-depth partitioning configurations. As a result, an average of 38% runtime reduction is achieved at the managable cost of less than 2% BD-rate loss.