Technical Information
Memory Requirement
The memory allocated by NewDSP() is as follows:
Ø N*(1+ 1.75*(sizeof COMPLEX)) if you allocate one block using NewDSP().
Ø N*(1+ 2.75*(sizeof COMPLEX)) if you allocate two blocks using NewDSP().
Optimization
A lot of effort has been done (as far as I could) in optimizing the design of this library regarding execution speed. Here are some hints to help you use it in an efficient way:
Ø Use an FFT length (N) of 256. My tests showed that this is the optimum length. After it comes 1024, then 64 (I don’t recommend a length of 4096 or above.
Ø Keep your signals & spectrum aligned in data segment.
Ø Of course using FilterSignal() is better than an FFT()-IFFT() pair. Using FilterSignal_1for2() is even better (if two signals are available for filtering). FFT_FloatInOut is faster than FFT() & so on…