fix comments in configuration file, fix initialization of subpic

cfg/nonCTC-SliceConfigExamples/subpicture_4Slice2VerSubPic.cfg

@@ -19,8 +19,8 @@ SubPicWidth                             : 4 3           # specifies the width of
 SubPicHeight                          	: 4 4           # specifies the height of the i-th subpicture in units of CtbSizeY
 SubPicTreatedAsPicFlag                  : 1 1           # equal to 1 specifies that the i-th subpicture of each coded picture in the CLVS is treated as a picture in the decoding process excluding in-loop filtering operations
 LoopFilterAcrossSubpicEnabledFlag       : 0 0           # equal to 1 specifies that in-loop filtering operations may be performed across the boundaries of the i-th subpicture in each coded picture in the CLVS
-SubPicIdPresentFlag                     : 0
-SubPicIdSignallingPresentFlag           : 0
+SubPicIdPresentFlag                     : 0             # equal to 1 specifies that the subpicture ID mapping is explicitly signalled, either in the SPS or in the PPSs
+SubPicIdSignallingPresentFlag           : 0             # specifies that subpicture ID mapping is signalled in the SPS(0: OFF, 1: ON)
 SubPicIdLen                             : 0             # the number of bits used to represent the syntax element sps_subpic_id[ i ]
 SubPicId                                : 0             # subpicture ID of the i-th subpicture
 

source/Lib/CommonLib/Slice.cpp

@@ -2634,6 +2634,13 @@ void PPS::initSubPic(const SPS &sps)
 {
   CHECK(getNumSubPics() > MAX_NUM_SUB_PICS, "Number of sub-pictures in picture exceeds valid range");
   m_subPics.resize(getNumSubPics());
+  // m_ctuSize,  m_picWidthInCtu, and m_picHeightInCtu might not be initialized yet.
+  if (m_ctuSize == 0 || m_picWidthInCtu == 0 || m_picHeightInCtu == 0)
+  {
+    m_ctuSize = sps.getCTUSize();
+    m_picWidthInCtu = (m_picWidthInLumaSamples + m_ctuSize - 1) / m_ctuSize;
+    m_picHeightInCtu = (m_picHeightInLumaSamples + m_ctuSize - 1) / m_ctuSize;
+  }
   for (int i=0; i< getNumSubPics(); i++)
   {
     m_subPics[i].setSubPicIdx(i);
@@ -2667,13 +2674,6 @@ void PPS::initSubPic(const SPS &sps)
     if (m_numSlicesInPic == 1)
     {
       CHECK(getNumSubPics() != 1, "only one slice in picture, but number of subpic is not one");
-      // m_ctuSize,  m_picWidthInCtu, and m_picHeightInCtu might not be initialized yet.
-      if (m_ctuSize == 0 || m_picWidthInCtu == 0 || m_picHeightInCtu == 0)
-      {
-        m_ctuSize = sps.getCTUSize();
-        m_picWidthInCtu = (m_picWidthInLumaSamples + m_ctuSize - 1) / m_ctuSize;
-        m_picHeightInCtu = (m_picHeightInLumaSamples + m_ctuSize - 1) / m_ctuSize;
-      }
       m_subPics[i].addAllCtusInPicToSubPic(0, getPicWidthInCtu(), 0, getPicHeightInCtu(), getPicWidthInCtu());
     }
     else