Wie effizientesten ein MultiSelect mit X% und Y-SegmentLength?

chunking(clip c, float percent, float lengthInSeconds) 
{
	clip = last
	cFrameCount = last.framecount # aktueller frame count
	cFrameRate = last.FrameRate() # aktuelle frame rate
	chunkLengthInFrames = Ceil(lenghtInSeconds*cFrameRate) # Länge eines chunks in frames
	maxChunkCount = Ceil(cFrameCount/chunkLengthInFrames) # maximal mögliche Anzahl an chunks dieser Länge
	actualChunkCount = Floor(maxChunkCount/100*percent) # Anzahl der chunks die verwendet werden
	distance = Ceil(cFrameCount/actualChunkCount) # Abstand zwischen chunks

	# die For-Schleife geht so nicht direkt in Avisynth, aber ich weiß nicht mehr direkt wie man die ordentlich in Avisynth-Syntax umschreibt :)
	for(int i = 0; i < cFrameCount; i = i + distance) { # sollte jetzt die chunks zusammen fügen
		ret = ret ++ Trim(i, -chunkLengthInFrames) 
	}
	return ret
}

const string DETECTION_SCRIPT = 
`Import("%s") #original script filename
global unused_ = blankclip(pixel_type="yv12", length=10).TFM()
file="%s"
global sep="-"
function IsMoving() {
  global b = (diff < 1.0) ? false : true}
c = last
global clip = last
c = WriteFile(c, file, "a", "sep", "b")
c = FrameEvaluate(c, "global a = IsCombedTIVTC(clip, cthresh=9)")
c = FrameEvaluate(c, "IsMoving")
c = FrameEvaluate(c,"global diff = YDifferenceFromPrevious(clip)")
crop(c,0,0,16,16)
SelectRangeEvery(%d,%d,0)
`;

function dumbSelect(clip c, float percent, float lengthInSeconds) 
{
	cFrameCount = c.framecount # current frame count; 37943 frames
	chunkLengthInFrames = Ceil(lengthInSeconds*c.FrameRate()) # chunk size in frames ; 5*29.97 = 149,85 -> 150
	maxChunkCount = Floor(cFrameCount/chunkLengthInFrames) # maximal possible chunk size; 37943/150 = 252,953 -> 252
	actualChunkCount = Floor(maxChunkCount*percent/100.0) # actual used chunk count; 252*5/100.0 = 12,6 -> 12
	distance = Floor(cFrameCount/actualChunkCount) # distance between chunks; 37943/12 = 3161,91 -> 3161
	return SelectRangeEvery(c, distance, chunkLengthInFrames) # selects and returns the wanted parts -> select 252 out of 3161 ; result should be 12*150
}
SetMemoryMax(768)
SetMTMode(6,0) # change MT mode
LoadPlugin("G:\Hybrid\avisynthPlugins\DGDecodeNV.dll")
LoadPlugin("G:\Hybrid\avisynthPlugins\TIVTC.dll")
# loading source
DGSource(dgi="H:\Temp\2799176231mp4_1259d7c77aa195f1a1313752923578cb_4827.dgi",fieldop=0)
RequestLinear(rlim=50,clim=50)
#without: 37943 frames; 5% would be 1897
#with dumbSelect 1811 frames shouldn't it be 1800?
return dumbSelect(last, 5, 5)