source = AVISource("C:\Videos\kite surf 04.15\Second flight.avi")

#####set parameters in the 'return Slowdn' line below to suit exact clip  slo-mo timing requirements  (steady - slowdown - steady slow - speedup - steady)#####

return Slowdn(source, 0, 160, 1.0, 1.0) ++ Slowdn(source, 160, 170, 1.0, 0.2) ++ Slowdn(source, 170, 210, 0.2, 0.2)++ Speedup(source, 210, 260, 0.2, 1.0)++ Speedup(source, 260, Framecount(source), 1.0, 1.0)


######The remainder of this script allows MVTools to control the slo-mo. --Thanks to 'lecapitan' from the Doom 9 forum for this clever piece of scripting....######

function Slowdn(clip source, int startFrame, int endFrame, float startRatio, float endRatio)
{  mfpsn = FramerateNumerator(source)
    mfpsd = FramerateDenominator(source)
    mclip = Trim(source, startFrame, endFrame)
    
   GScript(""" if (endFrame < startFrame) { temp = endFrame endFrame = startFrame startFrame = temp } """)
   
    super = MSuper(mclip, pel=4)
    backward_vec = MAnalyse(super, overlap=4, isb = true, blksize=8, truemotion=true, search=3)
    forward_vec = MAnalyse(super, overlap=4, isb = false, blksize=8, truemotion=true, search=3)
    slowdown = MFlowFPS(mclip, super, backward_vec, forward_vec, Round(mfpsn * 1.0/endRatio), mfpsd)
    slowdown = AssumeFPS(slowdown, mfpsn, mfpsd)
    startFrames = (mfpsn * 1.0/startRatio)/mfpsd                
    endFrames = (mfpsn * 1.0/endRatio)/mfpsd                   
    framesRange = endFrames - startFrames                       
    currentFrame = 0                                                      
    counter = 0                                                              
    lastFrame = Framecount(slowdown)                            
    desiredFrames = 0                                                    
    removeFrameCounter = 0                                          
    removeFrameThreshold = Float(endFrames)/Float(startFrames)  
    overflow = 0                                                           
    
    GScript(""" while (counter < lastFrame) { removeFrameCounter = removeFrameCounter + 1
    if (removeFrameCounter >= Floor(removeFrameThreshold + overflow)) {
    if (overflow > 1) { overflow = overflow - 1.0 }
    else { overflow = overflow + removeFrameThreshold - Floor(removeFrameThreshold) }
    # Calculate the desired frames. You could use a higher power to make the transition even smoother.
    desiredFrames = startFrames + Pow(Float(counter)/Float(lastFrame), 4) * framesRange
    removeFrameThreshold = Float(endFrames)/Float(desiredFrames)
    if (removeFrameThreshold < 1.1) { removeFrameThreshold = 1.0 overflow = 0 }
    removeFrameCounter = 0  }
    if (removeFrameCounter == 0) { currentFrame = currentFrame + 1  }
    else { slowdown = DeleteFrame(slowdown, currentFrame) }
    counter = counter + 1 }  """)
    
    slowdown = DeleteFrame(slowdown, Framecount(slowdown))
    return slowdown}


function Speedup(clip source, int startFrame, int endFrame, float startRatio, float endRatio)
{  mfpsn = FramerateNumerator(source)
    mfpsd = FramerateDenominator(source)
    mclip = Trim(source, startFrame, endFrame)

    GScript(""" if (endFrame < startFrame) { temp = endFrame endFrame = startFrame startFrame = temp } """)

    super = MSuper(mclip, pel=4)
    backward_vec = MAnalyse(super, overlap=4, isb = true, blksize=8, truemotion=true, search=3)
    forward_vec = MAnalyse(super, overlap=4, isb = false, blksize=8, truemotion=true, search=3)
    slowdown = MFlowFPS(mclip, super, backward_vec, forward_vec, Round(mfpsn * 1.0/startRatio), mfpsd)
    slowdown = AssumeFPS(slowdown, mfpsn, mfpsd)
    startFrames = (mfpsn * 1.0/startRatio)/mfpsd                 
    endFrames = (mfpsn * 1.0/endRatio)/mfpsd                   
    framesRange = startFrames - endFrames                       
    currentFrame = Framecount(slowdown)                         
    counter = 0                                                               
    lastFrame = Framecount(slowdown)                             
    desiredFrames = 0                                                     
    removeFrameCounter = 0                                          
    removeFrameThreshold = Float(startFrames)/Float(endFrames)  
    overflow = 0 
                                                               
    GScript(""" while (counter < lastFrame) { removeFrameCounter = removeFrameCounter + 1
    if (removeFrameCounter >= Floor(removeFrameThreshold + overflow)) {
    if (overflow > 1) { overflow = overflow - 1.0 }
    else { overflow = overflow + removeFrameThreshold - Floor(removeFrameThreshold)}
    # Calculate the desired frames. You could use a higher root to make the transition even smoother.
    desiredFrames = endFrames + Pow(Float(counter)/Float(lastFrame), 4) * framesRange
    removeFrameThreshold = Float(startFrames)/Float(desiredFrames)
    if (removeFrameThreshold < 1.1) { removeFrameThreshold = 1.0
    overflow = 0}
    removeFrameCounter = 0 }
    if (removeFrameCounter == 0) { currentFrame = currentFrame - 1 }
    else {slowdown = DeleteFrame(slowdown, currentFrame)
    currentFrame = currentFrame - 1 }
    counter = counter + 1 } """)
    
    return slowdown   }