YCbCr422To420_Interlace

Converts interlaced YCbCr image from 4:2:2 sampling format to 4:2:0 format.

Syntax

IppStatus ippiYCbCr422To420_Interlace_8u_P3R(const Ipp8u* pSrc[3], int srcStep[3], Ipp8u* pDst[3], int dstStep[3], IppiSize roiSize);

pSrc	Array of pointers to the ROI in each plane for source image.
srcStep	Array of distances in bytes between starts of consecutive lines in each plane for 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 fore 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.

The function ippiYCbCr422To420_Interlace is declared in the ippcc.h file. It operates with ROI (see Regions of Interest in Intel IPP).

This function converts the interlaced 4:2:2 image pSrc to the 4:2:0 image pDst (see Table “Planar Image Formats”).

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;

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.