Something

source = last

backward_vec2 = source.MVAnalyse(isb = true, delta = 2, pel = 2, overlap=4, sharp=2, idx = 1, truemotion=true)
backward_vec1 = source.MVAnalyse(isb = true, delta = 1, pel = 2, overlap=4, sharp=2, idx = 1, truemotion=true)
forward_vec1 = source.MVAnalyse(isb = false, delta = 1, pel = 2, overlap=4, sharp=2, idx = 1, truemotion=true)
forward_vec2 = source.MVAnalyse(isb = false, delta = 2, pel = 2, overlap=4, sharp=2, idx = 1, truemotion=true)
mask = mvmask(kind=1, vectors=forward_vec1).UtoY().spline36resize(720,432)#its very important that this line matches the resolution you are feeding the script with
smooth = source.degrainmedian(mode=3).fft3dfilter(bw=16, bh=16, bt=3, sigma=4, plane=0)
source2 = maskedmerge(source, smooth, mask)

source3 = source2.MVDegrain2(backward_vec1,forward_vec1,backward_vec2,forward_vec2,thSAD=400,idx=1)
source3.gradfun2db(1.5)