VarMeanDiff16x16

Evaluate means and variances, four 8X8 blocks of difference between two 16X16 blocks

Supported Technologies

SSE2

Synopsis

FwStatus   fwiVarMeanDiff16x16_8u32s_C1R ( const Fw8u * pSrcFw32s srcStepconst Fw8u * pRefFw32s refStepFw32s * pSrcSumFw32s * pVarFw32s * pMeanFw32s mcType );

Parameters

mcType   Specifies the type of prediction used for motion compensation.
pMean   Pointer to a computed mean of pixel values.
pRef   Pointer to a prefetch buffer which contains previously decoded bits.
pSrc   Pointer to a block of DCT coefficients.
pSrcSum   Pointer to a sum of pixel values for the current block.
pVar   Pointer to a variance value.
refStep   Reference block step size (width of the block in bytes).
srcStep   Source buffer step size (width of the buffer in bytes).

Description

This function evaluates the means and variances of two 8x8 blocks of difference between two 16x16 blocks of unsigned elements.

Parameter pSrcSum is used to avoid excessive computation as the function is repeatedly called for the same current block. pSrcSum must point to the array of four 8x8 blocks that make up the current block. Parameters pVar and pMean must point to four-element arrays because variance and mean are calculated for each 8x8 block.