function GuessParity(clip input){

input = AssumeFrameBased(input)

global guessparitytff = AssumeTFF(input).SeparateFields().Bob()
global guessparitybff = AssumeBFF(input).SeparateFields().Bob()

istff = input.AssumeTFF().Subtitle("Guessed TopFirst", x=20, y=20)

isbff = input.AssumeBFF().Subtitle("Guessed BottomFirst", x=20, y=20)

ConditionalFilter(guessparitytff, istff, isbff, "YDifferenceFromPrevious(guessparitytff) + YDifferenceToNext(guessparitytff)", "<", "YDifferenceFromPrevious(guessparitybff) + YDifferenceToNext(guessparitybff)", false)

}

## ShowParity by Wilbert

function ShowParity(clip clip) {

clip.subtitle(String(clip.GetParity?"TopFirst":"BottomFirst"), font="MS UI Gothic")

}

function GuessBob(clip input, string "expressiontff", "expressionbff"){

input = AssumeFrameBased(input)
expressiontff = Default(expressiontff, "Bob()")
expressionbff = Default(expressionbff, "Bob()")

global guessbobtff = AssumeTFF(input).SeparateFields().Bob()
global guessbobbff = AssumeBFF(input).SeparateFields().Bob()

input.AssumeTFF()
Eval(expressiontff)
istffa = last

istffb = istffa.SelectEven()
istffc = istffa.SelectOdd()

input.AssumeBFF()
Eval(expressionbff)
isbffa = last

isbffb = isbffa.SelectEven()
isbffc = isbffa.SelectOdd()

outputa = ConditionalFilter(guessbobtff, istffb, isbffb, "YDifferenceFromPrevious(guessbobtff) + YDifferenceToNext(guessbobtff)", "<", "YDifferenceFromPrevious(guessbobbff) + YDifferenceToNext(guessbobbff)", false)

outputb = ConditionalFilter(guessbobtff, istffc, isbffc, "YDifferenceFromPrevious(guessbobtff) + YDifferenceToNext(guessbobtff)", "<", "YDifferenceFromPrevious(guessbobbff) + YDifferenceToNext(guessbobbff)", false)

Interleave(outputa, outputb)

}