ipp 实现图像空间的转换

void Rgb2NV12(const unsigned char I[],
              const int image_width, 
              const int image_height,
              unsigned char J[])
{
    //memcpy(J, I, image_width*image_height*3);

    IppStatus ipp_status;

    int srcStep = image_width*3;
    int dstYStep = image_width;
    int dstCbCrStep = image_width;
    IppiSize roiSize = {image_width, image_height};

    const Ipp8u* pSrc = (Ipp8u*)I;

    Ipp8u *pDstY    = (Ipp8u*)J;                            //Y color plane is the first image_width*image_height pixels of J.
    Ipp8u *pDstCbCr    = (Ipp8u*)&J[image_width*image_height];    //In NV12 format, UV plane starts below Y.

    ipp_status = ippiRGBToYCbCr420_8u_C3P2R(pSrc, srcStep, pDstY, dstYStep, pDstCbCr, dstCbCrStep, roiSize);

    if (ipp_status != ippStsNoErr)
    {
        memset(J, 128, image_width*image_height*3/2);
    }
}

IPPAPI(IppStatus, ippiRGBToYCbCr420_8u_C3P2R,( const Ipp8u* pRGB, int rgbStep,  Ipp8u* pY, int YStep,Ipp8u* pCbCr, int CbCrStep, IppiSize roiSize ))//  RGB24-->NV12
IPPAPI(IppStatus, ippiRGBToYCbCr420_8u_C4P2R,( const Ipp8u* pRGB, int rgbStep,  Ipp8u* pY, int YStep,Ipp8u* pCbCr, int CbCrStep, IppiSize roiSize ))//  ARGB-->NV12
IPPAPI(IppStatus, ippiBGRToYCbCr420_8u_C3P2R,( const Ipp8u* pRGB, int rgbStep,  Ipp8u* pY, int YStep,Ipp8u* pCbCr, int CbCrStep, IppiSize roiSize ))//  BGR24-->NV12
IPPAPI(IppStatus, ippiBGRToYCbCr420_8u_AC4P2R,( const Ipp8u* pRGB, int rgbStep,  Ipp8u* pY, int YStep,Ipp8u* pCbCr, int CbCrStep, IppiSize roiSize ))// ABGR-->NV12

IppiSize roiSize;
roiSize.width = m_mfxEncParams.mfx.FrameInfo.CropW;
roiSize.height = m_mfxEncParams.mfx.FrameInfo.CropH;
mfxU16 pitch = m_pVPPSurfacesVPPOutEnc[nEncSurfIdx].Data.Pitch;
ippiBGRToYCbCr420_8u_AC4P2R( (Ipp8u*)pInputBuffer, roiSize.width*4,  (Ipp8u*)m_pVPPSurfacesVPPOutEnc[nEncSurfIdx].Data.Y, pitch, (Ipp8u*)m_pVPPSurfacesVPPOutEnc[nEncSurfIdx].Data.UV,pitch, roiSize);