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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_QuantInter_I.c
* OpenMAX DL: v1.0.2
* Revision: 9641
* Date: Thursday, February 7, 2008
*
*
*
*
* Description:
* Contains modules for inter Quantization
*
*/
#include "omxtypes.h"
#include "armOMX.h"
#include "omxVC.h"
#include "armCOMM.h"
/**
* Function: omxVCM4P2_QuantInter_I (6.2.4.4.3)
*
* Description:
* Performs quantization on an inter coefficient block; supports
* bits_per_pixel == 8.
*
* Input Arguments:
*
* pSrcDst - pointer to the input inter block coefficients; must be aligned
* on a 16-byte boundary.
* QP - quantization parameter (quantizer_scale)
* shortVideoHeader - binary flag indicating presence of short_video_header;
* shortVideoHeader==1 selects linear intra DC mode, and
* shortVideoHeader==0 selects non linear intra DC mode.
*
* Output Arguments:
*
* pSrcDst - pointer to the output (quantized) interblock coefficients.
* When shortVideoHeader==1, AC coefficients are saturated on the
* interval [-127, 127], and DC coefficients are saturated on the
* interval [1, 254]. When shortVideoHeader==0, AC coefficients
* are saturated on the interval [-2047, 2047].
*
* Return Value:
*
* OMX_Sts_NoErr - no error
* OMX_Sts_BadArgErr - bad arguments:
* - pSrcDst is NULL.
* - QP <= 0 or QP >= 32.
*
*/
OMXResult omxVCM4P2_QuantInter_I(
OMX_S16 * pSrcDst,
OMX_U8 QP,
OMX_INT shortVideoHeader
)
{
/* Definitions and Initializations*/
OMX_INT coeffCount;
OMX_INT fSign;
OMX_INT maxClpAC = 0, minClpAC = 0;
OMX_INT maxClpDC = 0, minClpDC = 0;
/* Argument error checks */
armRetArgErrIf(pSrcDst == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(((QP <= 0) || (QP >= 32)), OMX_Sts_BadArgErr);
/* One argument check is delayed until we have ascertained that */
/* pQMatrix is not NULL. */
/* Set the Clip Range based on SVH on/off */
if(shortVideoHeader == 1)
{
maxClpDC = 254;
minClpDC = 1;
maxClpAC = 127;
minClpAC = -127;
}
else
{
maxClpDC = 2047;
minClpDC = -2047;
maxClpAC = 2047;
minClpAC = -2047;
}
/* Second Inverse quantisation method */
for (coeffCount = 0; coeffCount < 64; coeffCount++)
{
fSign = armSignCheck (pSrcDst[coeffCount]);
pSrcDst[coeffCount] = (armAbs(pSrcDst[coeffCount])
- (QP/2))/(2 * QP);
pSrcDst[coeffCount] *= fSign;
/* Clip */
if (coeffCount == 0)
{
pSrcDst[coeffCount] =
(OMX_S16) armClip (minClpDC, maxClpDC, pSrcDst[coeffCount]);
}
else
{
pSrcDst[coeffCount] =
(OMX_S16) armClip (minClpAC, maxClpAC, pSrcDst[coeffCount]);
}
}
return OMX_Sts_NoErr;
}
/* End of file */
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