[pancserzso]

Thanks for the suggestions, but there is nothing I can do with the source at the moment. I am not sure if I need to do denoising or something else, but I would like to make it visually pleasing, without bright points / flickering in brightness.

Here are some filtering I have been trying:

DeGrainMedian(limitY=10, limitUV=13, mode=1, interlaced=false, norow=false)
DeGrainMedian(limitY=10, limitUV=13, mode=1, interlaced=false, norow=false)

=> result not too bad, handles the extreme noisy part quite well (2-7 sec)

FFT3DFilter(sigma=3, plane=4, bw=48, bh=48, bt=4, ow=16, oh=16, sharpen=0)

=> result

tr = 24
FFT3DFilter(sigma=12,bw=tr,bh=tr,ow=tr/2,oh=tr/2,bt=5,plane=0)

=> result

FFT3DFilter( sigma=6, plane=0, bt=5, bw=32, bh=32, ow=16, oh=16 )

=> result my favourite so far, but may be a bit too blurry

FluxSmoothST(temporal_threshold=7, spatial_threshold=7)

=> result

o = last
pre = o.fft3dfilter(sigma=8,sigma2=12,sigma3=10,sigma4=5,bw=24,bh=24,ow=12,oh=12,bt=5).FluxSmoothT(4)

sup1 = o.MSuper(hpad=16, vpad=16, pel=2, levels=1,sharp=2)
sup2 = pre.MSuper(hpad=16, vpad=16, pel=2, levels=0,sharp=0)
bv3  = MAnalyse(sup2,delta=3,truemotion=false,global=true,blksize=16,overlap=16/2,search=5,searchparam=4,isb=true, dct=5)
bv2  = MAnalyse(sup2,delta=2,truemotion=false,global=true,blksize=16,overlap=16/2,search=5,searchparam=4,isb=true, dct=5)
bv1  = MAnalyse(sup2,delta=1,truemotion=false,global=true,blksize=16,overlap=16/2,search=5,searchparam=4,isb=true, dct=5)
fv1  = MAnalyse(sup2,delta=1,truemotion=false,global=true,blksize=16,overlap=16/2,search=5,searchparam=4,isb=false,dct=5)
fv2  = MAnalyse(sup2,delta=2,truemotion=false,global=true,blksize=16,overlap=16/2,search=5,searchparam=4,isb=false,dct=5)
fv3  = MAnalyse(sup2,delta=3,truemotion=false,global=true,blksize=16,overlap=16/2,search=5,searchparam=4,isb=false,dct=5)

o.MDegrain3(sup1,bv1,fv1,bv2,fv2,bv3,fv3,thSAD=360)

=> result really nice looking result at the beginning (0-1 sec) and the end (7-16 sec), but really bad in the middle (2-7 sec)