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

ID 790148
Date 3/22/2024
Public
Document Table of Contents

DCT8x8To2x2Inv, DCT8x8To4x4Inv

Perform an inverse DCT on a 2D buffer of 8x8 size with further downsampling to 2x2 or 4x4 size.

Syntax

IppStatus ippiDCT8x8To2x2Inv_16s_C1(const Ipp16s* pSrc, Ipp16s* pDst);

IppStatus ippiDCT8x8To4x4Inv_16s_C1(const Ipp16s* pSrc, Ipp16s* pDst);

IppStatus ippiDCT8x8To2x2Inv_16s_C1I(Ipp16s* pSrcDst);

IppStatus ippiDCT8x8To4x4Inv_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.

pSrcDst

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

Description

These functions compute the inverse discrete cosine transform of the 2D buffer pSrc of 8x8 size. Then the functions perform downsampling of the result by averaging to the destination buffer pDst of size 2x2 or 4x4.

In-place flavors of the functions perform operations on the source and destination buffer pSrcDst.

CAUTION:

Source data for 16s flavors must be the result of the forward discrete cosine transform of data from the range [-256, 255], they cannot be arbitrary data from the range [-32768, 32767].

Return Values

ippStsNoErr

Indicates no error. Any other value indicates an error.

ippStsNullPtrErr

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