There is no constructor for DistParam class in TComRdCost.h. Currently, there is a reliance on setting all members to valid values outside this class before computing distortion.

For example, this can cause a problem with TComRdCost::getDistPart( Pel* piCur, Int iCurStride, Pel* piOrg, Int iOrgStride, UInt uiBlkWidth, UInt uiBlkHeight, DFunc eDFunc ) function. When this function is called with DF_SADS or DF_HADS variants for eDFunc (I don't think such a call is present in the current code though), the function would return meaningless results and sometimes can cause encoder crash due to memory violation. This is because a member of DistParam class (cDtParam.iStep) is not set. Setting this value to 1 would be reasonable here.

The recommendation is to create a constructor for DistParam class. Furthermore, some members (pCb*, pCr*) are never used and can probably be removed to avoid confusion.