Details

Autor(en) / Beteiligte

• Yang, Haitao
• Chen, Huanbang
• Chen, Jianle
• Esenlik, Semih
• Sethuraman, Sriram
• Xiu, Xiaoyu
• Alshina, Elena
• Luo, Jiancong

Titel

Subblock-Based Motion Derivation and Inter Prediction Refinement in the Versatile Video Coding Standard

Ist Teil von

• IEEE transactions on circuits and systems for video technology, 2021-10, Vol.31 (10), p.3862-3877

Ort / Verlag

New York: IEEE

Erscheinungsjahr

2021

Link zum Volltext

Quelle

IEEE Xplore Digital Library

Beschreibungen/Notizen

• Efficient representation and coding of fine-granular motion information is one of the key research areas for exploiting inter-frame correlation in video coding. Representative techniques towards this direction are affine motion compensation (AMC), decoder-side motion vector refinement (DMVR), and subblock-based temporal motion vector prediction (SbTMVP). Fine-granular motion information is derived at subblock level for all the three coding tools. In addition, the obtained inter prediction can be further refined by two optical flow-based coding tools, the bi-directional optical flow (BDOF) for bi-directional inter prediction and the prediction refinement with optical flow (PROF) exclusively used in combination with AMC. The aforementioned five coding tools have been extensively studied and finally adopted in the Versatile Video Coding (VVC) standard. This paper presents technical details of each tool and highlights the design elements with the consideration of typical hardware implementations. Following the common test conditions defined by Joint Video Experts Team (JVET) for the development of VVC, 5.7% bitrate reduction on average is achieved by the five tools. For test sequences characterized by large and complex motion, up to 13.4% bitrate reduction is observed. Additionally, visual quality improvement is demonstrated and analyzed.