Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference

ID 790148
Date 10/31/2024
Public
Document Table of Contents

BWTInv

Performs the inverse BWT transform.

Syntax

IppStatus ippsBWTInv_8u(const Ipp8u* pSrc, Ipp8u* pDst, int len, int index, Ipp8u* pBWTInvBuff);

Include Files

ippdc.h

Domain Dependencies

Headers: ippcore.h, ippvm.h, ipps.h

Libraries: ippcore.lib, ippvm.lib, ipps.lib

Parameters

pSrc

Pointer to the source vector.

pDst

Pointer to the destination vector.

len

Number of elements in the source and destination vectors.

index

Index of first position for the inverse BWT transform.

pBWTInvBuff

Pointer to the additional buffer.

Description

This function performs the inverse BWT transform of len elements starting from pIndex element of the source vector pSrc and stores result in the vector pDst. The function uses the external buffer pBWTInvBuff. The size of this buffer must be computed by calling the function ippsBWTInvGetSize beforehand.

Return Values

ippStsNoErr

Indicates no error.

ippStsNullPtrErr

Indicates an error if one of the specified pointers is NULL.

ippStsSizeErr

Indicates an error if len is less than or equal to 0.

Example

The code example below shows how to use the function ippsBWTInv_8u.

void func_BWT() {
	int wndSize = 8;
	int pBWTFwdBuffSize;
	int pBWTInvBuffSize;
	
	Ipp8u pSrc[] = "baadeffg";
	int len = 8;
	int pIndex;
	
	Ipp8u* pDst = ippsMalloc_8u(len);
	Ipp8u* pDstInv = ippsMalloc_8u(len);
	
	ippsBWTFwdGetSize_8u(wndSize, &pBWTFwdBuffSize);
	Ipp8u* pBWTFwdBuff = ippsMalloc_8u(pBWTFwdBuffSize);
	ippsBWTFwd_8u(pSrc, pDst, len, &pIndex, pBWTFwdBuff);
	
	ippsBWTInvGetSize_8u( wndSize, &pBWTInvBuffSize);
	Ipp8u* pBWTInvBuff = ippsMalloc_8u(pBWTInvBuffSize);
	ippsBWTInv_8u(pDst, pDstInv, len, pIndex, pBWTInvBuff);
}

Result:

    
pDst ->     "bagadeff"
pDstInv ->  "baadeffg"