SampleDown444LS

Creates 444 MCU with level shift from pixel-order data.

Syntax

IppStatus ippiSampleDown444LS_MCU_8u16s_C3P3R(const Ipp8u* pSrc, int srcStep, Ipp16s* pDstMCU[3]);

Parameters

pSrc	Pointer to the source image ROI.
srcStep	Distance in bytes between starts of consecutive lines in the source image.
pDstMCU	Array of 3 pointers to the destination image blocks.

Description

The function ippiSampleDown444LS_MCU is declared in the ippj.h file. It operates with ROI (see Regions of Interest in Intel IPP).

This function converts interleaved data to the 444 MCU that consists of three 8x8 blocks - one block for each channel (see Figure “MCU Structure for Different JPEG Sampling Formats”).

Additionally, this function converts data from unsigned Ipp8u range [0..255] to the signed Ipp16s range [-128..127 ] performing level shift operation (by subtracting 128).

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error condition if any of the specified pointers are NULL.
ippStsStepErr	Indicates an error condition if srcStep has a zero or negative value.