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      1 /**
      2  *
      3  * File Name:  omxVCM4P2_DCT8x8blk.c
      4  * OpenMAX DL: v1.0.2
      5  * Revision:   9641
      6  * Date:       Thursday, February 7, 2008
      7  *
      8  * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
      9  *
     10  *
     11  *
     12  * Description:
     13  * Contains modules for 8x8 block DCT
     14  *
     15  */
     16 
     17 #include <math.h>
     18 #include "omxtypes.h"
     19 #include "armOMX.h"
     20 
     21 #include "armCOMM.h"
     22 #include "armVCM4P2_DCT_Table.h"
     23 
     24 /**
     25  * Function:  omxVCM4P2_DCT8x8blk   (6.2.4.4.1)
     26  *
     27  * Description:
     28  * Computes a 2D forward DCT for a single 8x8 block, as defined in
     29  * [ISO14496-2].
     30  *
     31  * Input Arguments:
     32  *
     33  *   pSrc - pointer to the start of the linearly arranged input buffer; must
     34  *            be aligned on a 16-byte boundary.  Input values (pixel
     35  *            intensities) are valid in the range [-255,255].
     36  *
     37  * Output Arguments:
     38  *
     39  *   pDst - pointer to the start of the linearly arranged output buffer; must
     40  *            be aligned on a 16-byte boundary.
     41  *
     42  * Return Value:
     43  *
     44  *    OMX_Sts_NoErr - no error
     45  *    OMX_Sts_BadArgErr - bad arguments, returned if:
     46  *    -    pSrc or pDst is NULL.
     47  *    -    pSrc or pDst is not 16-byte aligned.
     48  *
     49  */
     50 
     51 OMXResult omxVCM4P2_DCT8x8blk (const OMX_S16 *pSrc, OMX_S16 *pDst)
     52 {
     53     OMX_INT x, y, u, v;
     54 
     55     /* Argument error checks */
     56     armRetArgErrIf(pSrc == NULL, OMX_Sts_BadArgErr);
     57     armRetArgErrIf(!armIs16ByteAligned(pSrc), OMX_Sts_BadArgErr);
     58     armRetArgErrIf(pDst == NULL, OMX_Sts_BadArgErr);
     59     armRetArgErrIf(!armIs16ByteAligned(pDst), OMX_Sts_BadArgErr);
     60 
     61 
     62     for (u = 0; u < 8; u++)
     63     {
     64         for (v = 0; v < 8; v++)
     65         {
     66             OMX_F64 sum = 0.0;
     67             for (x = 0; x < 8; x++)
     68             {
     69                 for (y = 0; y < 8; y++)
     70                 {
     71                     sum += pSrc[(x * 8) + y] *
     72                        armVCM4P2_preCalcDCTCos[x][u] *
     73                        armVCM4P2_preCalcDCTCos[y][v];
     74                 }
     75             }
     76             pDst[(u * 8) + v]= armRoundFloatToS16 (sum);
     77         }
     78     }
     79 
     80     return OMX_Sts_NoErr;
     81 }
     82 
     83 
     84 
     85 /* End of file */
     86 
     87 
     88