JVET-S0097: set default values in VPS

Set default values when the bitstream does not contain any VPS

source/Lib/CommonLib/TypeDef.h

@@ -67,6 +67,8 @@
 #define JVET_S_SUB_PROFILE                                1 // Move signalling of ptl_num_sub_profiles
 
 #define JVET_R0324_REORDER                                1 // Reordering of syntax elements JVET-R0324/JVET-R2001-v2
+ 
+#define JVET_S0097_VPS_default_values                     1 // JVET-S0097: infer values of variables in VPS when not present
 
 #define JVET_S0219_ASPECT2_CHANGE_ORDER_APS_PARAMS_TYPE   1 // JVET-S0219 aspect2: change the order to put the aps_params_type before the aps_adaptation_parameter_set_id.
 

source/Lib/DecoderLib/DecLib.cpp

@@ -1534,6 +1534,20 @@ void DecLib::xActivateParameterSets( const InputNALUnit nalu )
 
     // update the stored VPS to the actually referred to VPS
     m_vps = m_parameterSetManager.getVPS(sps->getVPSId());
+#if JVET_S0097_VPS_default_values
+    if(sps->getVPSId() == 0)
+    {
+      //No VPS in bitstream: set defaults values of variables in VPS to the ones signalled in SPS
+      m_vps->setMaxSubLayers( sps->getMaxTLayers() );
+      m_vps->setLayerId( 0, sps->getLayerId() );
+      m_vps->deriveOutputLayerSets(); 
+    }
+    else
+    {
+      //VPS in the bitstream: check that SPS and VPS signalling are compatible
+      CHECK(sps->getMaxTLayers() > m_vps->getMaxSubLayers(), "The SPS signals more temporal sub-layers than allowed by the VPS");
+    }
+#endif
 
     m_parameterSetManager.getApsMap()->clearActive();
     for (int i = 0; i < ALF_CTB_MAX_NUM_APS; i++)