Module 

Header 
/Engine/Source/Runtime/SignalProcessing/Public/DSP/FFTAlgorithm.h 
Include 
#include "DSP/FFTAlgorithm.h" 
namespace Audio
{
enum EFFTScaling
{
None,
MultipliedByFFTSize,
MultipliedBySqrtFFTSize,
DividedByFFTSize,
DividedBySqrtFFTSize,
}
}
Name 
Description 

None 
No scaling needed to maintain equal energy. 
MultipliedByFFTSize 
Output is effectively multiplied by FFTSize. 
MultipliedBySqrtFFTSize 
Output is effectively multiplied by the square root of the FFTSize. 
DividedByFFTSize 
Output is effectively divided by the square root of the FFTSize. 
DividedBySqrtFFTSize 
Output is effectively divided by the square root of the FFTSize. 
EFFTScaling
EFFTScaling describes how transformed data is scaled. IFFTAlgorithm implementations must return this value to describe how to achieve equal energy between input data and transformed data. It is assumed that applying the logical inverse of the scaling will produce equal energy.