Mismatch between spec and VTM on signalling of sn_layer_id

[wangyang.cs]

1. There is a mismatch between spec and VTM on signalling of sn_layer_id.

In VTM-10.0, sn_layer_id is parsed with index from 0 to m_snNumLayersMinus1 inclusive.
In void SEIReader::xParseSEIScalableNesting()

  if (sei.m_snOlsFlag)
  {
    ...
  }
  else
  {
    sei_read_flag(decodedMessageOutputStream, symbol, "sn_all_layers_flag"); sei.m_snAllLayersFlag = symbol;
    if (!sei.m_snAllLayersFlag)
    {
      sei_read_uvlc(decodedMessageOutputStream, symbol, "sn_num_layers_minus1"); sei.m_snNumLayersMinus1 = symbol;
      for (uint32_t i = 0; i <= sei.m_snNumLayersMinus1; i++)
      {
        sei_read_code(decodedMessageOutputStream, 6, symbol, "sn_layer_id[i]"); sei.m_snLayerId[i] = symbol;
      }
    }
  }

sn_layr_id is parsed with index from 0 to m_snNumLayersMinus1 inclusive.

However, in JVET-T2001-v1, sn_layer_id is signalled with index from 1 to m_snNumLayersMinus1 inclusive.
D.6.1 Scalable nesting SEI message syntax
scalable_nesting( payloadSize ) {

sn_ols_flag
sn_subpic_flag
if( sn_ols_flag ) {

sn_num_olss_minus1
for( i = 0; i <= sn_num_olss_minus1; i++ )

sn_ols_idx_delta_minus1[ i ]

} else {

sn_all_layers_flag
if( !sn_all_layers_flag ) {

sn_num_layers_minus1
for( i = 1; i <= sn_num_layers_minus1; i++ )

sn_layer_id[ i ]

}

}

2. There is a typo in void SEIReader::parseSEImessage()

{
const SEIMessages pictureTiming = getSeisByType(seiListInCurNalu, SEI::PICTURE_TIMING);
CHECK(hrd.getGeneralHrdParameters().getGeneralSamePicTimingInAllOlsFlag() && pictureTiming.size() > 0 && pictureTiming.size() != pictureTiming.size(), ...
}

should be corrected as follows:

{
const SEIMessages pictureTiming = getSeisByType(seiListInCurNalu, SEI::PICTURE_TIMING);
CHECK(hrd.getGeneralHrdParameters().getGeneralSamePicTimingInAllOlsFlag() && pictureTiming.size() > 0 && pictureTiming.size() != seiListInCurNalu.size(),...
}

[wangyang.cs]

A MR ​https://vcgit.hhi.fraunhofer.de/jvet/VVCSoftware_VTM/-/merge_requests/1940 is submitted.

[ksuehring]

fixed as suggested