Function TComYuv::removeHighFreq is called only during ME for bipredictive case, where clipping of the unidirectional part is done as in the following:

pDst[x ] = xClip( (pDst[x ]<<1) - pSrc[x ] );

This makes the prediction operation to be (O is the predicted signal, R1 and R2 are references):

(clip(2*O - R1) - R2 )/ 2

When clipping is omitted, results for 24 frames are as follows (based on HM-3.0-dev):

                  Random access              Random access LoCo
         Y BD-rateU BD-rateV BD-rateY BD-rateU BD-rateV BD-rate
Class A  0.0      0.0      0.2      0.0     -0.1     -0.2 
Class B  0.1     -0.1     -0.1      0.0     -0.1      0.1 
Class C -0.1     -0.3      0.1      0.0     -0.5     -0.3 
Class D  0.0     -0.4     -0.3     -0.2     -0.2     -0.6 
All      0.0     -0.2     -0.1     -0.1     -0.2     -0.2 
 
                                                      
         Low delay                           Low delay LoCo
         Y BD-rateU BD-rateV BD-rateY BD-rateU BD-rateV BD-rate
Class B -0.1     -0.3     -0.1      0.0      0.1      0.2 
Class C  0.0      0.2     -0.1      0.0      0.2      0.2 
Class D  0.0      0.0      0.4     -0.2     -0.2     -0.6 
Class E -0.1      0.1     -0.2      0.0     -0.1      0.2 
All     -0.1      0.0      0.0      0.0      0.0      0.0