private Ratio CalculateFramerate()
{
Maybe <string> rawTrackTextMaybe = from track in _videoTrack.Value
select track.Framerate;
Maybe <Ratio> fpsFromParenthesis = from framerateText in rawTrackTextMaybe
let startParenths = framerateText.IndexOf("(")
let endParenths = framerateText.IndexOf(")")
where startParenths != -1 && endParenths != -1
let fpsSubstring = framerateText.Substring(startParenths + 1, endParenths - startParenths - 1)
let splitOnSlash = fpsSubstring.Split('/')
where splitOnSlash.Length == 2
let numerator = NumericUtils.TryParseInt(splitOnSlash[0])
let denominator = NumericUtils.TryParseInt(splitOnSlash[1])
where numerator != null && denominator != null
select new Ratio(numerator.Value, denominator.Value);
Maybe <Ratio> fpsFromDirectParse = from framerateText in rawTrackTextMaybe
let indexOfFpsMarker = framerateText.IndexOf("fps", StringComparison.OrdinalIgnoreCase)
where indexOfFpsMarker != -1
let fpsAsDecimal = framerateText.Substring(0, indexOfFpsMarker - 2)
let fpsAsDouble = NumericUtils.TryParseDouble(fpsAsDecimal)
where fpsAsDouble != null
select NumericUtils.ConvertDoubleToFPS(fpsAsDouble.Value);
return(fpsFromParenthesis.Or(fpsFromDirectParse).OrElse(new Ratio()));
}