Developer Reference for Intel® Integrated Performance Primitives 2018
Computes lowpass FIR filter coefficients.
IppStatus ippsFIRGenLowpass_64f(Ipp64f rFreq, Ipp64f* pTaps, int tapsLen, IppWinType winType, IppBool doNormal, Ipp8u* pBuffer);
ipps.h
Headers: ippcore.h, ippvm.h
Libraries: ippcore.lib, ippvm.lib
rFreq |
Normalized cutoff frequency, must be in the range (0, 0.5). |
pTaps |
Pointer to the array where computed tap values are stored. The number of elements in the array is tapsLen. |
tapsLen |
Number of elements in the array containing the tap values; must be equal or greater than 5. |
winType |
Specifies what type of window is used in computations. The winType must have one of the following values:
|
doNormal |
Specifies normalized or non-normalized sequence of the filter coefficients is computed. The doNormal must have one of the following values:
|
pBuffer |
Pointer to the buffer for internal calculations. To get the size of the buffer, use the ippsFIRGenGetBufferSize function. |
This function computes tapsLen coefficients for lowpass FIR filter with the cutoff frequency rFreq by windowing the ideal infinite filter coefficients. The quality of filtering is defined by the number of coefficients. The parameter winType specifies the type of the window. For more information on window types used by the function, see Windowing Functions. The computed coefficients are stored in the array pTaps.
For more information about the used algorithm, see [MIT 93].
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when the pTaps pointer is NULL. |
ippStsSizeErr |
Indicates an error when the tapsLen is less than 5, or rFreq is out of range. |