CbYCr422ToYCbCr420

Converts interlaced 4:2:2 CbYCr image to 4:2:0 YCbCr image.

Syntax

IppStatus ippiCbYCr422ToYCbCr420_Interlace_8u_C2P3R(const Ipp8u* pSrc, int srcStep, Ipp8u* pDst[3], int dstStep[3], IppiSize roiSize);

Parameters

pSrc	Pointer to the source image ROI.
srcStep	Distance in bytes between starts of consecutive lines in the source image.
pDst	Array of pointers to the ROI in each plane for destination image.
dstStep	Array of distances in bytes between starts of consecutive lines in each plane for a three-plane destination image.
roiSize	Size of the source and destination ROI in pixels, its width must be multiple of 2, and height must be multiple of 4.

Description

The function ippiCbYCr422ToYCbCr420_Interlace is declared in the ippcc.h file. It operates with ROI (see Regions of Interest in Intel IPP ).

This function converts interlaced 4:2:2 CbYCr two-channel image pSrc to the 4:2:0 YCbCr three-plane image pDst (see Table “Pixel-Order Image Formats” and Table “Planar Image Formats”). The source image has the following sequence of samples: Cb0, Y0, Cr0, Y1, Cb1, Y2, Cr1, Y3, Cb2, ... . Three-plane destination image has the following order of pointers: Y-plane, Cb-plane, Cr-plane.

The conversion is performed in accordance with the following formulas:

Y1_dest = Y1_src;

Cb0(Cr0)_dest = (3*Cb0(Cr0)_src + Cb2(Cr2)_src + 2)/4;

Cb1(Cr1)_dest = (Cb1(Cr1)_src + 3*Cb3(Cr3)_src + 2)/4;

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error.
ippStsNullPtrErr	Indicates an error condition if any of the specified pointers is NULL.
ippStsSizeErr	Indicates an error condition if roiSize.width is less than 2, or roiSize.height is less than 4.
ippStsDoubleSize	Indicates a warning if roiSize.width is not multiple of 2, or roiSize.height is not multiple of 4.