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      1 /**
      2  *
      3  * File Name:  armVCM4P10_InterpolateHalfDiag_Luma.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  * Description:
     12  * This functions will help to calculate Half Pel luma interpolation
     13  *
     14  */
     15 
     16 #include "omxtypes.h"
     17 #include "armOMX.h"
     18 #include "omxVC.h"
     19 
     20 #include "armCOMM.h"
     21 #include "armVC.h"
     22 
     23 
     24 /**
     25  * Function: armVCM4P10_InterpolateHalfDiag_Luma
     26  *
     27  * Description:
     28  * This function performs interpolation for (1/2, 1/2)  positions
     29  * around a full-pel position.
     30  *
     31  * Remarks:
     32  *
     33  *  [in]    pSrc        Pointer to top-left corner of block used to interpolate
     34  *                      in the reconstructed frame plane
     35  *  [in]    iSrcStep    Step of the source buffer.
     36  *  [in]    iDstStep    Step of the destination(interpolation) buffer.
     37  *  [in]    iWidth      Width of the current block
     38  *  [in]    iHeight     Height of the current block
     39  *  [out]   pDst        Pointer to the interpolation buffer of the (1/2,1/2)-pel
     40  *
     41  * Return Value:
     42  * Standard OMXResult value.
     43  *
     44  */
     45 
     46 OMXResult armVCM4P10_InterpolateHalfDiag_Luma(
     47         const OMX_U8*     pSrc,
     48         OMX_U32     iSrcStep,
     49         OMX_U8*     pDst,
     50         OMX_U32     iDstStep,
     51         OMX_U32     iWidth,
     52         OMX_U32     iHeight
     53 )
     54 {
     55     OMX_S32     HalfCoeff, pos;
     56     OMX_S16     Buf [21 * 16];  /* 21 rows by 16 pixels per row */
     57     OMX_U32     y, x;
     58 
     59     /* check for argument error */
     60     armRetArgErrIf(pSrc == NULL, OMX_Sts_BadArgErr)
     61     armRetArgErrIf(pDst == NULL, OMX_Sts_BadArgErr)
     62 
     63     /*
     64      * Intermediate values will be 1/2 pel at Horizontal direction
     65      * Starting at (0.5, -2) at top extending to (0.5, height + 3) at bottom
     66      * Buf contains a 2D array of size (iWidth)X(iHeight + 5)
     67      */
     68     for (y = 0; y < iHeight + 5; y++)
     69     {
     70         for (x = 0; x < iWidth; x++)
     71         {
     72             pos = (y-2) * iSrcStep + x;
     73             HalfCoeff =
     74                 pSrc [pos - 2] -
     75                 5 * pSrc [pos - 1] +
     76                 20 * pSrc [pos] +
     77                 20 * pSrc [pos + 1] -
     78                 5 * pSrc [pos + 2] +
     79                 pSrc [pos + 3];
     80             Buf [y * iWidth + x] = (OMX_S16)HalfCoeff;
     81         } /* x */
     82     } /* y */
     83 
     84     /* Vertical interpolate */
     85     for (y = 0; y < iHeight; y++)
     86     {
     87         for (x = 0; x < iWidth; x++)
     88         {
     89             pos = y * iWidth + x;
     90             HalfCoeff =
     91                 Buf [pos] -
     92                 5 * Buf [pos + 1 * iWidth] +
     93                 20 * Buf [pos + 2 * iWidth] +
     94                 20 * Buf [pos + 3 * iWidth] -
     95                 5 * Buf [pos + 4 * iWidth] +
     96                 Buf [pos + 5 * iWidth];
     97 
     98             HalfCoeff = (HalfCoeff + 512) >> 10;
     99             HalfCoeff = armClip(0, 255, HalfCoeff);
    100 
    101             pDst [y * iDstStep + x] = (OMX_U8) HalfCoeff;
    102         }
    103     }
    104 
    105     return OMX_Sts_NoErr;
    106 }
    107