Visible to Intel only — GUID: GUID-70F07A51-F781-43ED-A926-32905898A875
Visible to Intel only — GUID: GUID-70F07A51-F781-43ED-A926-32905898A875
DFTFwd_Direct_CToC
Computes the forward discrete Fourier transform of a complex signal.
Syntax
IppStatus ippsDFTFwd_Direct_CToC_16fc(const Ipp16fc *pSrc, Ipp16fc *pDst, int length);
Include Files
ipps.h
Domain Dependencies
Flavors declared in ipps.h:
Headers: ippcore.h, ippvm.h
Libraries: ippcore.lib, ippvm.lib
Parameters
pSrc |
Pointer to the input array containing complex values. |
pDst |
Pointer to the output array containing complex values. |
length |
Length of transform |
Description
This function computes the forward DFT according to the transform length.
The function operating on the complex data type processes the input complex array pSrc and stores the result in pDst.
Data vectors for this function must be aligned to an appropriate number of bytes that is determined by the SIMD width that is supported by the customer's platform - use ippMalloc function for such alignment.
The direct form of DFT uses the static twiddle tables and therefore supports only the limited set of transform lengths. 47 DFT lengths and 11 FFT lengths: 12, 24, 36, 48, 60, 72, 96, 108, 120, 144, 180, 192, 216, 240, 288, 300, 324, 360, 384, 432, 480, 540, 576, 600, 648, 720, 768, 864, 900, 960, 972, 1080, 1152, 1200, 1296, 1440, 1500, 1536, 1620, 1920, 1944, 2160, 2400, 2700, 2916, 3000, 3240 - DFT, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096 - FFT
The forward DFT functionality can be described as follows:
where k is the index of elements in the frequency domain, n is the index of elements in the time domain, N is the input signal len, and A is a multiplier equal to 1.0 (no normalization). Also, x(n) is pSrc[n] and X(k) is pDst[k].
Product and Performance Information |
---|
Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex. Notice revision #20201201 |
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when one of the specified pointers with exception of pBuffer is NULL. |
ippStsSizeErr |
This length is not supported by direct function. |