[BUG] MvToolsFPSmod (AviSynth) - output plays too fast with wrong number of frames

[Selur]

try:

function MvToolsFPSmod(clip C, int "NewNum", int "NewDen", string "Preset")
{
    Preset = Default(Preset, "Film")
    P_Film = 1 P_MusicVideoClip = 2
    Pset = Preset == Preset == "Film" ? P_Film : Preset == "MusicVideoClip" ? P_MusicVideoClip : P_Film
    thSCD2nom= (Pset==P_Film) ? 130 : (Pset==P_MusicVideoClip) ? 255 : 130
    NewNum = Default(NewNum, 60)
    NewDen = Default(NewDen, 1)
    
    FramRat = Floor(Framerate( C ))
    FramRatNew = Floor(NewNum / NewDen)
    NewNumN = (FramRatNew / 2 == FramRat) ? FramRatNew : FramRat*5

    superfilt = MSuper(C, hpad=8, vpad=8, pel=4, sharp=2, rfilter=4)
    bak = MAnalyse(superfilt, isb=true, blksize=16, blksizev=16, badSAD=1000, badrange=-3, overlap=0, overlapv=0, search=4, searchparam=0, dct=5)
    fwd = MAnalyse(superfilt, isb=false, blksize=16, blksizev=16, badSAD=1000, badrange=-3, overlap=0, overlapv=0, search=4, searchparam=0, dct=5)
    Flow = MFlowFps(C, superfilt, bak, fwd, num=NewNum, den=NewDen, blend=False, ml=5800, mask=0, thSCD2=thSCD2nom)

    return Flow
}

Cu Selur