Some Intel IPP functions use special structures to store function-specific (context) information. For example, the

IppsFFTSpec

structure stores twiddle factors and bit reverse indexes needed in the fast Fourier transform.

Two different kinds of structures are used:

The function context interpretation is processor dependent. Therefore, these context-related structures are not defined in the public headers, and their fields are not accessible. Intel IPP provides no option of modifying these structures or creating a function context as an automatic variable.