Intel® Integrated Performance Primitives Developer Guide and Reference

ID 790148
Date 11/07/2023
Public

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Document Table of Contents

DCT8x8FwdLS

Performs a forward DCT on a 2D buffer of 8x8 size with prior data conversion and level shift.

Syntax

IppStatus ippiDCT8x8FwdLS_8u16s_C1R(const Ipp8u* pSrc, int srcStep, Ipp16s* pDst, Ipp16s addVal);

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 buffer.

pDst

Pointer to the destination buffer.

srcStep

Distance in bytes between starts of consecutive lines in the source image buffer.

addVal

The level shift value.

Description

This function operates with ROI (see Regions of Interest in Intel IPP) that is a 2D buffer of 8x8 size in this case, thus there is no need to specify its size.

This function first converts data in the buffer pSrc from unsigned Ipp8u type to the signed Ipp16s type and then performs level shift operation by adding the constant value addVal to each sample. After that, the function performs the forward discrete cosine transform of the modified data. The result is stored in pDst.

Return Values

ippStsNoErr

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

ippStsNullPtrErr

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

ippStsStepErr

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