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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_IDCT8x8blk.c
* OpenMAX DL: v1.0.2
* Revision: 9641
* Date: Thursday, February 7, 2008
*
*
*
*
* Description:
* Contains modules for 8x8 block IDCT
*
*/
#include <math.h>
#include "omxtypes.h"
#include "armOMX.h"
#include "omxVC.h"
#include "armCOMM.h"
#include "armVCM4P2_DCT_Table.h"
/**
* Function: omxVCM4P2_IDCT8x8blk (6.2.3.2.1)
*
* Description:
* Computes a 2D inverse DCT for a single 8x8 block, as defined in
* [ISO14496-2].
*
* Input Arguments:
*
* pSrc - pointer to the start of the linearly arranged IDCT input buffer;
* must be aligned on a 16-byte boundary. According to
* [ISO14496-2], the input coefficient values should lie within the
* range [-2048, 2047].
*
* Output Arguments:
*
* pDst - pointer to the start of the linearly arranged IDCT output buffer;
* must be aligned on a 16-byte boundary.
*
* Return Value:
*
* OMX_Sts_NoErr - no error
* OMX_Sts_BadArgErr - bad arguments:
* - pSrc or pDst is NULL.
* - pSrc or pDst is not 16-byte aligned.
*
*/
OMXResult omxVCM4P2_IDCT8x8blk (const OMX_S16 *pSrc, OMX_S16 *pDst)
{
OMX_INT x, y, u, v;
/* Argument error checks */
armRetArgErrIf(pSrc == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(!armIs16ByteAligned(pSrc), OMX_Sts_BadArgErr);
armRetArgErrIf(pDst == NULL, OMX_Sts_BadArgErr);
armRetArgErrIf(!armIs16ByteAligned(pDst), OMX_Sts_BadArgErr);
for (x = 0; x < 8; x++)
{
for (y = 0; y < 8; y++)
{
OMX_F64 sum = 0.0;
for (u = 0; u < 8; u++)
{
for (v = 0; v < 8; v++)
{
sum += pSrc[(u * 8) + v] *
armVCM4P2_preCalcDCTCos[x][u] *
armVCM4P2_preCalcDCTCos[y][v];
}
}
pDst[(x * 8) + y] = (OMX_S16) floor(sum + 0.5);
/* Saturate to [-256, 255] */
pDst[(x * 8) + y] = armClip (
-256,
255,
pDst[(x * 8) + y]);
}
}
return OMX_Sts_NoErr;
}
/* End of file */
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