CalmGrain (old)

function CalmGrain(clip clp,int "tstr",float "nboost",bool "soften")
{
# Requirements: RemoveGrain(SSE3).dll, FluxSmooth.dll, MaskTools2
# By yours truly, Bloax.

# ~~~~~ Wuzzis now?
# This 'should' calm grain down, whether or not it improves compressibility is a good question.
# It certainly reduces the eye-tearing effect of heavy noise compression artifacts post-encoding though. :-)
# ~~~~~

# ~~~~~ Wuzzis do now?
# "tstr" Is the strength of FluxSmoothT, higher values cause more pixels to hang around for the ride.
# Use values around 10 (for very slight reduction) to about 30-50 (or 255 if you so wish), too high values can look bad though.

# "nboost" Is a little something I'd hope tricks RemoveGrain to detect more grain. (Contrast boosting, *cough*)
# Just leave it at the default value, unless you feel like messing around with it.

# "soften" Adds a little blurring before FluxSmooth kicks in.
# Results are quite nice, though it blurs the scene a little bit.
# ~~~~~

tstr = Default(tstr, 25)
nboost = Default(nboost, 1.5)
soften = Default(soften, false)

a = clp.IsYV12() ? clp : clp.ConvertToYV12()

b = a.Tweak(Cont=1.66*nboost,Bright=-33*nboost,interp=0).RemoveGrain(mode=4,modeu=-1).RemoveGrain(mode=9,modeu=-1).Tweak(Cont=0.66/nboost,Bright=33)
c = Mt_MakeDiff(a,b).Mt_Expand().Mt_Inflate()
d = soften ? a.RemoveGrain(mode=19).FluxSmoothT(tstr) : a.FluxSmoothT(tstr)
Mt_Merge(a,d,c)
}