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

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

DCT8x8Inv, DCT8x8Inv_A10

Performs an inverse DCT on a 2D buffer of 8x8 size.

Syntax

Case 1: Not-in-place operation

IppStatus ippiDCT8x8Inv_<mod>(const Ipp<datatype>* pSrc, Ipp<datatype>* pDst);

Supported values for mod:

16s_C1

32f_C1

IppStatus ippiDCT8x8Inv_A10_16s_C1(const Ipp16s* pSrc, Ipp16s* pDst);

Case 2: Not-in-place operation with ROI

IppStatus ippiDCT8x8Inv_<mod>(const Ipp<srcDatatype>* pSrc, Ipp<dstDatatype>* pDst, int dstStep);

Supported values for mod:

16s_C1R

16s8u_C1R

Case 3: In-place operation

IppStatus ippiDCT8x8Inv_<mod>(Ipp<datatype>* pSrcDst);

Supported values for mod:

16s_C1I

32f_C1I

IppStatus ippiDCT8x8Inv_A10_16s_C1I( Ipp16s* pSrcDst);

Include Files

ippi.h

Domain Dependencies

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

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

Parameters

pSrc

Pointer to the source image.

pDst

Pointer to the destination buffer.

dstStep

Distance in bytes between starts of consecutive lines in the destination buffer for operations with ROI.

pSrcDst

Pointer to the source and destination image for in-place operations.

Description

Some flavors operate with ROI (see Regions of Interest in Intel IPP).

This function computes the inverse discrete cosine transform of data in a 2D buffer of 8x8 size. No prerequisites are needed to use this transform function.

CAUTION:

Source data for 16s functions must be the result of the forward discrete cosine transform of data from the range [-512, 511] for flavors with A10 modifier (ippiDCT8x8Inv_A10), and from the range [-256, 255] for flavors without A10 modifier (ippiDCT8x8Inv); they cannot be arbitrary data from the range [-32768, 32767].

Return Values

ippStsNoErr

Indicates no error. Any other value indicates an error or a warning.

ippStsNullPtrErr

Indicates an error condition if pSrc, pDst, or pSrcDst pointer is NULL.

ippStsStepErr

Indicates an error condition if dstStep value is zero or negative.