encoder rootCbf calculation bug

[zhaoyin]

The rootCbf is calculated by the following code, i.e., using the cbf of the first TU inside CU to derive the root cbf. It may be wrong when a CU is tiled into multiple TUs (i.e., the first TU has cbf = 0 but any other TU has cbf = 1). A fix (see "ROOT_CBF_FIX") is to use the cbf of trDepth = 0 instead.
However, this fix does not bring gain on average.

const int numValidTBlocks = ::getNumberValidTBlocks( *cs.pcv );
for (uint32_t i = 0; i < numValidTBlocks; i++)
{

#if ROOT_CBF_FIX <- fix here

cu.rootCbf |= TU::getCbfAtDepth( firstTU, ComponentID( i ), 0 );

#else

cu.rootCbf |= TU::getCbf( firstTU, ComponentID( i ) );

#endif

}

[ksuehring]

BMS is not maintained anymore. VTM is the currently supported reference software of VVC. If the report is still valid, please re-open and assign to VTM.