Missing context initialization for TsResidualSign in BDPCM mode

[auyeung]

In VTM6.0, we have

const CtxSet ContextSetCfg::TsResidualSign = ContextSetCfg::addCtxSet
({
  {  28,  25,  53, CNU, CNU, CNU, },
  {   5,  10,  53, CNU, CNU, CNU, },
  {  20,   2,  46, CNU, CNU, CNU, },
  {   1,   4,   4, DWS, DWS, DWS, },
});

The context initialization values for BDPCM mode is missing. It might be caused by not using classF.cfg for Class F and Class TGM test sequences in the retraining process.

Suggested value based on JVET-N-CE1 retraining method:

const CtxSet ContextSetCfg::TsResidualSign = ContextSetCfg::addCtxSet
({
  {  28,  25,  53,  35,  26,  30, },
  {   5,  10,  53,  35,  33,  38, },
  {  20,   2,  46,  28,  33,  38, },
  {   1,   4,   4,   5,   5,   8, },
});

[fbossen]

The reason init values show as "CNU" is that the class F config file was broken in VTM 6.0rc1, which is the version that was used for training.

The class F config file was broken here:
​https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/merge_requests/731/

and fixed here:
​https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/merge_requests/858/

I expect other syntax elements might affected by this. Unless you have data showing this has a significant impact, I wouldn't bother fixing this until the next training round (VTM 7.0).