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/* ----------------------------------------------------------------
*
*
* File Name: omxVCM4P10_TransformDequantChromaDCFromPair.c
* OpenMAX DL: v1.0.2
* Revision: 9641
* Date: Thursday, February 7, 2008
*
* (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
*
*
*
* H.264 inverse quantize and transform module
*
*/
#include "omxtypes.h"
#include "armOMX.h"
#include "omxVC.h"
#include "armCOMM.h"
#include "armVC.h"
/*
* Description:
* Dequantize Chroma 2x2 DC block
*/
static void DequantChromaDC2x2(
OMX_S16* pDst,
OMX_INT QP
)
{
int Shift = (QP/6)-1 ;
int Scale = armVCM4P10_VMatrix[QP%6][0];
int i, Value;
if (Shift >= 0)
{
for (i=0; i<4; i++)
{
Value = (pDst[i] * Scale) << Shift;
pDst[i] = (OMX_S16)Value;
}
}
else
{
for (i=0; i<4; i++)
{
Value = (pDst[i] * Scale) >> 1;
pDst[i] = (OMX_S16)Value;
}
}
}
/*
* Description:
* Inverse Transform DC 2x2 Coefficients
*/
static void InvTransformDC2x2(OMX_S16* pData)
{
int c00 = pData[0];
int c01 = pData[1];
int c10 = pData[2];
int c11 = pData[3];
int d00 = c00 + c01;
int d01 = c00 - c01;
int d10 = c10 + c11;
int d11 = c10 - c11;
pData[0] = (OMX_S16)(d00 + d10);
pData[1] = (OMX_S16)(d01 + d11);
pData[2] = (OMX_S16)(d00 - d10);
pData[3] = (OMX_S16)(d01 - d11);
}
/**
* Function: omxVCM4P10_TransformDequantChromaDCFromPair (6.3.4.2.2)
*
* Description:
* Reconstruct the 2x2 ChromaDC block from coefficient-position pair buffer,
* perform integer inverse transformation, and dequantization for 2x2 chroma
* DC coefficients, and update the pair buffer pointer to next non-empty
* block.
*
* Input Arguments:
*
* ppSrc - Double pointer to residual coefficient-position pair buffer
* output by CALVC decoding
* QP - Quantization parameter QpC
*
* Output Arguments:
*
* ppSrc - *ppSrc is updated to the start of next non empty block
* pDst - Pointer to the reconstructed 2x2 ChromaDC coefficients buffer;
* must be aligned on a 4-byte boundary.
*
* Return Value:
* OMX_Sts_NoErr, if the function runs without error.
* OMX_Sts_BadArgErr - bad arguments: if one of the following cases occurs:
* - ppSrc or pDst is NULL.
* - pDst is not 4-byte aligned.
* - QP is not in the range of [0-51].
*
*/
OMXResult omxVCM4P10_TransformDequantChromaDCFromPair(
const OMX_U8 **ppSrc,
OMX_S16* pDst,
OMX_INT QP
)
{
armRetArgErrIf(ppSrc == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(*ppSrc == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(pDst == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(armNot4ByteAligned(pDst), OMX_Sts_BadArgErr);
armRetArgErrIf(QP<0, OMX_Sts_BadArgErr);
armRetArgErrIf(QP>51, OMX_Sts_BadArgErr);
armVCM4P10_UnpackBlock2x2(ppSrc, pDst);
InvTransformDC2x2(pDst);
DequantChromaDC2x2(pDst, QP);
return OMX_Sts_NoErr;
}
/* End of file */
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