Question about how to aggregate the MV for the AV_Motion feature

[Easoncyx]

Hi,
Thanks for the great work. I had a question about the way MV_Length for each frame are calcualted.
Av_Motion feature is calcualted from S->MV_Length.
For each PU, there is a NormFwd and NormBwd multiplied to each decoded MV before calculating the sum.
Any insight why is this factor multipled to MV? Does the MV need to be scaled based on the POC difference? I counldn't find any reference related to this factor.

HEVC calculation of the Norm factor

bitstream_mode3_videoparser/VideoParser/VideoStatHEVC.c

Lines 112 to 115 in 0995775

	if( (CurrType == FORWARD) || (CurrType == DIRECT) || (CurrType == BIDIRECT) )
	NormFwd = 1.0 / (2 * fabs( (FrmStat->CurrPOC - Ref0POC) / (double)FrmStat->POC_DIF )) ;
	if( (CurrType == BACKWARD) || (CurrType == DIRECT) || (CurrType == BIDIRECT) )
	NormBwd = 1.0 / (2 * fabs( (FrmStat->CurrPOC - Ref1POC) / (double)FrmStat->POC_DIF )) ;

HEVC mutipling the Norm factor on MV

bitstream_mode3_videoparser/VideoParser/VideoStatHEVC.c

Lines 132 to 133 in 0995775

	mvX = abs( (int)(CurrMvF->mv [0].x) ) * NormFwd ;
	mvY = abs( (int)(CurrMvF->mv [0].y) ) * NormFwd ;