Deoldify Vapoursynth filter

[Dan64]

Hello Selur,

  I found a way to stabilize DDColor, with a method that I called AdaptiveMerge, the problem is that is too slow.
  Using this method the encoding speed is reduced by 50% and this method is very simple, I was unable to find a way to speed up the computation.
  I don't know very well Vapoursynth and the available documentation is "poor". Maybe there is a way to get a faster encoding...
  The current code is the following

  

def AdaptiveMerge3(clipa: vs.VideoNode = None, clipb: vs.VideoNode = None, clipb_weight: float = 0.0) -> vs.VideoNode:
    #Vapoursynth version
    def merge_frame(n, f):               
        clip1 = clipa[n]
        clip2 = clipb[n] 
        clip2_yuv = clip2.resize.Bicubic(format=vs.YUV444PS, matrix_s="709", range_s="limited") 
        clip2_avg_y = vs.core.std.PlaneStats(clip2_yuv, plane=0)
        luma = clip2_avg_y.get_frame(0).props['PlaneStatsAverage']
        #vs.core.log_message(2, "Luma(" + str(n) + ") = " + str(luma))
        brightness = min(1.5 * luma, 1)
        w = max(clipb_weight * brightness, 0.15)
        clip3 = vs.core.std.Merge(clip1, clip2, weight=w)  
        f_out = f.copy()
        f_out = clip3.get_frame(0)
        return f_out
    clipm = clipa.std.ModifyFrame(clips=clipa, selector=merge_frame)
    return clipm

  Since DDColor on dark scenes shows a psychedelic effect (try to use it with the attached video), the adaptive merge "weight" the weight_merge parameter by the brightness of the image.
  In order to not penalize too much DDColor I multiply this value by 1.2.
  For example if the brightness is 45% and the weight_merge is 50% the effective weight used in the merge is given by = 50%*(1.2*45%) = 27%
  This computation must executed at frame level.
  Do you have any idea on how it is possible to speed up the function AdaptiveMerge3 ?

Thanks,
Dan