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      1 /*
      2  * Copyright (C) 2007-2008 ARM Limited
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  *
     16  */
     17 /**
     18  *
     19  * File Name:  armVCM4P10_InterpolateHalfDiag_Luma.c
     20  * OpenMAX DL: v1.0.2
     21  * Revision:   9641
     22  * Date:       Thursday, February 7, 2008
     23  *
     24  *
     25  *
     26  * Description:
     27  * This functions will help to calculate Half Pel luma interpolation
     28  *
     29  */
     30 
     31 #include "omxtypes.h"
     32 #include "armOMX.h"
     33 #include "omxVC.h"
     34 
     35 #include "armCOMM.h"
     36 #include "armVC.h"
     37 
     38 
     39 /**
     40  * Function: armVCM4P10_InterpolateHalfDiag_Luma
     41  *
     42  * Description:
     43  * This function performs interpolation for (1/2, 1/2)  positions
     44  * around a full-pel position.
     45  *
     46  * Remarks:
     47  *
     48  *  [in]    pSrc        Pointer to top-left corner of block used to interpolate
     49  *                      in the reconstructed frame plane
     50  *  [in]    iSrcStep    Step of the source buffer.
     51  *  [in]    iDstStep    Step of the destination(interpolation) buffer.
     52  *  [in]    iWidth      Width of the current block
     53  *  [in]    iHeight     Height of the current block
     54  *  [out]   pDst        Pointer to the interpolation buffer of the (1/2,1/2)-pel
     55  *
     56  * Return Value:
     57  * Standard OMXResult value.
     58  *
     59  */
     60 
     61 OMXResult armVCM4P10_InterpolateHalfDiag_Luma(
     62         const OMX_U8*     pSrc,
     63         OMX_U32     iSrcStep,
     64         OMX_U8*     pDst,
     65         OMX_U32     iDstStep,
     66         OMX_U32     iWidth,
     67         OMX_U32     iHeight
     68 )
     69 {
     70     OMX_S32     HalfCoeff, pos;
     71     OMX_S16     Buf [21 * 16];  /* 21 rows by 16 pixels per row */
     72     OMX_U32     y, x;
     73 
     74     /* check for argument error */
     75     armRetArgErrIf(pSrc == NULL, OMX_Sts_BadArgErr)
     76     armRetArgErrIf(pDst == NULL, OMX_Sts_BadArgErr)
     77 
     78     /*
     79      * Intermediate values will be 1/2 pel at Horizontal direction
     80      * Starting at (0.5, -2) at top extending to (0.5, height + 3) at bottom
     81      * Buf contains a 2D array of size (iWidth)X(iHeight + 5)
     82      */
     83     for (y = 0; y < iHeight + 5; y++)
     84     {
     85         for (x = 0; x < iWidth; x++)
     86         {
     87             pos = (y-2) * iSrcStep + x;
     88             HalfCoeff =
     89                 pSrc [pos - 2] -
     90                 5 * pSrc [pos - 1] +
     91                 20 * pSrc [pos] +
     92                 20 * pSrc [pos + 1] -
     93                 5 * pSrc [pos + 2] +
     94                 pSrc [pos + 3];
     95             Buf [y * iWidth + x] = (OMX_S16)HalfCoeff;
     96         } /* x */
     97     } /* y */
     98 
     99     /* Vertical interpolate */
    100     for (y = 0; y < iHeight; y++)
    101     {
    102         for (x = 0; x < iWidth; x++)
    103         {
    104             pos = y * iWidth + x;
    105             HalfCoeff =
    106                 Buf [pos] -
    107                 5 * Buf [pos + 1 * iWidth] +
    108                 20 * Buf [pos + 2 * iWidth] +
    109                 20 * Buf [pos + 3 * iWidth] -
    110                 5 * Buf [pos + 4 * iWidth] +
    111                 Buf [pos + 5 * iWidth];
    112 
    113             HalfCoeff = (HalfCoeff + 512) >> 10;
    114             HalfCoeff = armClip(0, 255, HalfCoeff);
    115 
    116             pDst [y * iDstStep + x] = (OMX_U8) HalfCoeff;
    117         }
    118     }
    119 
    120     return OMX_Sts_NoErr;
    121 }
    122