Zeropad to lowest possible order of two

 gives the greatest speed since the Fourier transform is executed faster when the length of the data is order of two (e.g. 1024 samples which is 2 to the order of 10). If the time window applied to the time data does not have length that is an order of two, the data will be padded with zeros at the end to obtain this length. E.g. if the length of the time window is 700 samples, zeros are added from sample 701 etc. to obtain the length 1024.

Usually zeros are used for this padding, therefore this is usually called Zeropadding, but WinMLS does not pad zeros, instead it pads the last value of the windowed data. This is done to prevent from errors in case the data has a DC-component.

Note: Because this method is applied, this setting should not be used with a Rectangular window on non-transient data (this is not recommended in any case).