International organisation for standardisation

Partial merge;

Planar prediction for chroma;

Adaptive switching on/off combined coding for CAVLC.

Various methods to simplify ALF-related tools were also investigated including:

8. 
   Region-based ALF only;
   
9. 
   Single pass ALF;
   
10. 
    One filter only for ALF.
    

It is also recommended in this contribution that a tool experiment similar to TE12 for HM1.0 establishment stage be done before the current WD moves to committee draft (CD).

This contribution underlines the desire, also reported in the discussion of the software integration AHG report, that confirmation testing be performed immediately after integration of each adopted proposal to make sure it is providing the intended benefit.

Agreed principles:

• 
  Confirmation of intended benefit is to be performed immediately after integration of the full set of adoptions from a meeting cycle (which implies having the ability to disable each adoption individually).
  
• 
  Contributions of things to remove/simplify are to be treated in the same way as other proposals.
  

This contribution presents results of tests applied to several tools in the current WD and HM (3.0) to verify whether the included tool produced the intended effects. Each set of results have been cross-checked. Based on the results, this contribution recommends removal of the following tools as they do not show clear benefits in terms of coding efficiency, complexity and even for the design consistency: Center position of TMVP candidates; Chroma codeword switch; Direct coding of Intra DC coefficient in CAVLC mode; Parallel deblocking filter decision; Partial merge; and Planar prediction for chroma; Adaptive switching on/off combined coding for CAVLC. Various methods to simplify ALF-related tool were also investigated including: Region-based ALF only; Single pass ALF and One filter only for ALF. It is also recommend in this contribution that a tool experiments similar to TE12 for HM1.0 establishment stage be done before current WD moves to committee draft (CD).

Relates to the issue discussed previously in the context of the software AHG: There is no mechanism currently to perform a sanity check about integrated tools and their interaction. It should be implemented as mandatory exercise starting from this meeting, that after completion of the new software bundle the benefit of each integrated tool is proven again.

In general, it is agreed that an exercise of investigating benefit of tools is useful, and people should be encouraged to proceed on this. It is however doubted that an exercise like TE12 would be useful to achieve this. Instead, proposals for simplification or removal should be investigated in the usual process of CE.

The suggested specific recommended actions were allocated for consideration in the context of the relevant respective topics.