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/*
* Copyright (C) 2007-2008 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
/**
*
* File Name: omxVCM4P2_QuantInvIntra_I.c
* OpenMAX DL: v1.0.2
* Revision: 9641
* Date: Thursday, February 7, 2008
*
*
*
*
* Description:
* Contains modules for intra inverse Quantization
*
*/
#include "omxtypes.h"
#include "armOMX.h"
#include "omxVC.h"
#include "armCOMM.h"
/**
* Function: omxVCM4P2_QuantInvIntra_I (6.2.5.3.2)
*
* Description:
* Performs the second inverse quantization mode on an intra/inter coded
* block. Supports bits_per_pixel = 8. The output coefficients are clipped to
* the range [-2048, 2047].
*
* Input Arguments:
*
* pSrcDst - pointer to the input (quantized) intra/inter block; must be
* aligned on a 16-byte boundary.
* QP - quantization parameter (quantizer_scale)
* videoComp - video component type of the current block. Takes one of the
* following flags: OMX_VC_LUMINANCE, OMX_VC_CHROMINANCE (intra
* version only).
* shortVideoHeader - binary flag indicating presence of short_video_header
* (intra version only).
*
* Output Arguments:
*
* pSrcDst - pointer to the output (dequantized) intra/inter block
*
* Return Value:
*
* OMX_Sts_NoErr - no error
* OMX_Sts_BadArgErr - bad arguments; one or more of the following is
* true:
* - pSrcDst is NULL
* - QP <= 0 or QP >=31
* - videoComp is neither OMX_VC_LUMINANCE nor OMX_VC_CHROMINANCE.
*
*/
OMXResult omxVCM4P2_QuantInvIntra_I(
OMX_S16 * pSrcDst,
OMX_INT QP,
OMXVCM4P2VideoComponent videoComp,
OMX_INT shortVideoHeader
)
{
/* Initialized to remove compilation error */
OMX_INT dcScaler = 0, coeffCount, Sign;
/* Argument error checks */
armRetArgErrIf(pSrcDst == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(((QP <= 0) || (QP >= 32)), OMX_Sts_BadArgErr);
armRetArgErrIf(((videoComp != OMX_VC_LUMINANCE) && (videoComp != OMX_VC_CHROMINANCE)), OMX_Sts_BadArgErr);
/* Calculate the DC scaler value */
/* linear intra DC mode */
if(shortVideoHeader)
{
dcScaler = 8;
}
/* nonlinear intra DC mode */
else
{
if (videoComp == OMX_VC_LUMINANCE)
{
if (QP >= 1 && QP <= 4)
{
dcScaler = 8;
}
else if (QP >= 5 && QP <= 8)
{
dcScaler = 2 * QP;
}
else if (QP >= 9 && QP <= 24)
{
dcScaler = QP + 8;
}
else
{
dcScaler = (2 * QP) - 16;
}
}
else if (videoComp == OMX_VC_CHROMINANCE)
{
if (QP >= 1 && QP <= 4)
{
dcScaler = 8;
}
else if (QP >= 5 && QP <= 24)
{
dcScaler = (QP + 13)/2;
}
else
{
dcScaler = QP - 6;
}
}
}
/* Dequant the DC value, this applies to both the methods */
pSrcDst[0] = pSrcDst[0] * dcScaler;
/* Saturate */
pSrcDst[0] = armClip (-2048, 2047, pSrcDst[0]);
/* Second Inverse quantisation method */
for (coeffCount = 1; coeffCount < 64; coeffCount++)
{
/* check sign */
Sign = armSignCheck (pSrcDst[coeffCount]);
if (QP & 0x1)
{
pSrcDst[coeffCount] = (2* armAbs(pSrcDst[coeffCount]) + 1) * QP;
pSrcDst[coeffCount] *= Sign;
}
else
{
pSrcDst[coeffCount] =
(2* armAbs(pSrcDst[coeffCount]) + 1) * QP - 1;
pSrcDst[coeffCount] *= Sign;
}
/* Saturate */
pSrcDst[coeffCount] = armClip (-2048, 2047, pSrcDst[coeffCount]);
}
return OMX_Sts_NoErr;
}
/* End of file */
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