Evaluate predicted 4X4 block
|FwStatus||fwiGetDiff4x4_8u16s_C1||(||const Fw8u * pSrcCur, Fw32s srcCurStep, const Fw8u * pSrcRef, Fw32s srcRefStep, Fw16s * pDstDiff, Fw32s dstDiffStep, Fw16s * pDstPredictor, Fw32s dstPredictorStep, Fw32s mcType, Fw32s roundControl );|
|dstDiffStep||Destination block step size (width of the block in bytes).|
|dstPredictorStep||Destination predictor block step size (width of the block in bytes).|
|mcType||Specifies the type of prediction used for motion compensation.|
|pDstDiff||Pointer to a 16X16 block in the destination plane which contains differences between current and reference blocks.|
|pDstPredictor||Pointer to a destination predictor block.|
|pSrcCur||Pointer to a block in the current plane.|
|pSrcRef||Pointer to a block in the reference plane.|
|roundControl||Specifies the type of rounding used for half-pixel approximation.|
|srcCurStep||Source current block step size (width of the block in bytes)|
|srcRefStep||Source reference block step size (width of the block in bytes)|
This function compares a 4X4 source block to an 4X4 reference block and writes results to a difference block and a predictor block in a destination plane. The results are used to reduce error when subsequent blocks that refer to the source block are encoded.
Values in the predictor block are based on the values in a reference block, using a compensation type specified by the mcType parameter.
When mcType = FWVC_MC_APX_FF, the reference block is used as the predictor block.
When mcType = FWVC_MC_APX_FH or FWVC_MC_APX_HF, each element of the predictor block is the average of two reference block elements.
When mcType = FWVC_MC_APX_HH, each element of the predictor block is the average of four reference block elements.
Encoding has half-pixel accuracy, and a rounding method must be specified.