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AVS2/3 is the National Standard of the People's Republic of China.

AVS3 is divided into the 3 following parts:

  • Part 1: System;
  • Part 2: Video;
  • Part 3: Audio.

Part 2 is divided into 2 parts:

  • AVS3-phase1;
  • AVS3-phase2;

AVS3 Video uses only really effective and the most used algorithms and technologies.

AVS3-phase1 has coding-transform unit (CTU) splitting modes like HEVC and uses the most efficient additional algorithms sets for Intra coding:

  • Intra Prediction Filter (IPF)
  • Two-Step cross Component Prediction Mode (TSCPM)
  • Derived Tree (DT) splitting
  • Derived Tree (DT) splitting

and additional algorithms sets for inter coding:

  • Adaptive Motion Vector Resolution (AMVR)
  • History-based MV Prediction (HMVP)
  • Extended AMVR (EMVR)
  • Ultra MV Expression (UMVE) scheme
  • Affine motion prediction
  • Symmetric MV Difference (SMVD)

and for filtering:

  • Adaptive Leveling Filter (ALF)

It allows the AVS3-phase1 standard to keep efficiency above HEVC but not to be significantly slower.

AVS3-phase2 is under development and currently uses much more algorithms sets:

  • Extended Intra Prediction Mode (EIPM)
  • Enhanced TSCPM (ETSCPM)
  • Implicit Selection of Transforms (IST)
  • Multiple Intra Prediction Filter (MIPF)
  • Prediction from Multiple Cross-components (PMC)
  • Intra Prediction Filter for chroma (IPF_Chroma)
  • Improved Intra Prediction (IIP)
  • Spatial Angular Weighted Prediction (SAWP)
  • Intra Block Copy (IBC)
  • Frequency-based Intra Mode Coding (FIMC)
  • Implicit Selection of Transform Skip (ISTS)

Additional inter sets:

  • Sub-Block Transform (SBT)
  • Decoder side MV Refinement (DMVR)
  • Bi-directional Optical Flow (BIO)
  • Inter Prediction Filtering (InterPF)
  • Motion Vector Angular Prediction (MVAP)
  • Affine UMVE
  • Angular Weighted Prediction (AWP)
  • AWP with Motion Vector Refinement (AWP_MVR)
  • Enhanced Temporal MV Prediction (ETMVP)
  • Subblock-based TMVP (SbTMVP)
  • Enhanced UMVE
  • Overlapped Block Motion Compensation (OBMC)
  • Bi-directional Gradient Correction (BGC)
  • Affine Secondary Prediction (ASP)
  • Inter Predictor Correction (IPC)
  • Transform Skip for inter blocks (TS_Inter)
  • String Prediction (SP)

Transform and filtering sets:

  • Scan Region-based Coefficient Coding(SRCC)
  • Counter-based multi-probability CABAC
  • Enhanced Secondary Transform (EST)
  • Secondary Transform for Intra Chroma residual (STC)
  • DeBlocking Refinement (DBR)
  • Enhanced Sample Adaptive Offset (ESAO)
  • Cross-Component Sample Adaptive Offset (CCSAO)
  • ALF enhancement (EALF)
  • Neuro Network filter (NNLF)

Those instruments may give AVS3-phase2 efficiency near VVC’s one with faster execution.