DCT8x8Fwd

Performs forward DCT on an 8x8 block of a chrominance part of NV12 plane.

Syntax

IppStatus ippiDCT8x8Fwd_8u16s_C2P2(const Ipp8u* pSrc, Ipp32s srcStep, Ipp16s* pDstU, Ipp16s* pDstV);

Parameters

pSrc	Pointer to the source image buffer.
srcStep	Distance in bytes between starts of consecutive lines in the source image buffer for operations with ROI.
pDst	Pointer to the destination image buffer.
pSrcDst	Pointer to the source and destination image for in-place operations.

Description

The function ippiDCT8x8Fwd_8u16s_C2P2 is declared in the ippvc.h file.

This function performs a forward discrete cosine transform on an 8x8 block of a chrominance part of NV12 plane and places the results into separate 8x8 blocks for U(Cb) and V(Cr) components.

NV12 Plane:

YY YY YY YY YY YY YY YY UV UV UV UV - chrominance part of NV12 plane.

The code example below illustrates the usage of ippiDCT8x8Fwd_8u16s_C2P2 function.

ippiDCT8x8Fwd_8u16s_C2P2 Usage Example

{
    // the pointer to the source block (chrominance part of NV12 plane)
    const Ipp8u *pSrcUV = src_block_ptr;
    // Step of the current source block
    Ipp32s srcStep = src_step;
    // the pointer to the destination buffer for U coefficients of DCT
    Ipp16s dstU[64];
    Ipp16s *pDstU = &dstU[0];
    // the pointer to the destination buffer for V coefficients of DCT
    Ipp16s dstV[64];
    Ipp16s *pDstV = &dstV[0];
    ippiDCT8x8Fwd_8u16s_C2P2(pSrc,srcStep,pDstU,pDstV );
}

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error condition if any of the pointers is NULL.
ippStsStepErr	Indicates an error condition if the step value is negative.