WHT

Syntax

IppStatus ippgWHT_32f(const Ipp32f* pSrc, Ipp32f* pDst, int order, int flag, Ipp8u* pBuffer);

IppStatus ippgWHT_64f(const Ipp64f* pSrc, Ipp64f* pDst, int order, int flag, Ipp8u* pBuffer);

IppStatus ippgWHT_<order>_32f(const Ipp32f* pSrc, Ipp32f* pDst, int flag, Ipp8u* pBuffer);

IppStatus ippgWHT_<order>_64f(const Ipp64f* pSrc, Ipp64f* pDst, int flag, Ipp8u* pBuffer);

supported value for <order>: integer in the range [1, 13].

Parameters

pSrc	Pointer to the input array.
pDst	Pointer to the output array.
flag	Specifies the result normalization method. The values for the flag argument are described in the section Flag and Hint Arguments.
order	Specifies the number of the samples 2^order in the source signal [1, 13].
pBuffer	Pointer to the working buffer.

Description

The function ippgWHT is declared in the ippgen.h file.

The function computes the discrete Walsh-Hadamard transform (WHT) of a real signal for the fixed number of samples 2^order. The number of samples can be specified by the parameter order, or by choosing the function flavor designed for the specific length of the signal and containing order in the function name, for example, the function flavor ippgWHT_11_32f performs the WHT of the 2¹¹ samples of the source signal. Intel IPP support WHT functions for fixed number of input samples corresponding to the values of order in the range [1, 13].

Caution

Data vectors for these functions 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.

Optimization Notice
Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice. Notice revision #20110804

Optimization Notice

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804

To avoid listing all the similar prototypes of function flavors of this type, only templates are given here. In the template the <order> modifier in a function name denotes a correspondent value of order.

The normalization method of the result is specified by the parameter flag.

This function requires the working buffer, its size must be computed with the function ippgWHTGetBufferSize beforehand.

The WHT is an involutary transform and the same function can be used both for forward and inverse transforms.

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error when one of the specified pointers is NULL.
ippStsFftFlagErr	Indicates an error when the flag value is incorrect.