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      1 /* ----------------------------------------------------------------
      2  *
      3  *
      4  * File Name:  armVCM4P10_PredictIntraDC4x4.c
      5  * OpenMAX DL: v1.0.2
      6  * Revision:   9641
      7  * Date:       Thursday, February 7, 2008
      8  *
      9  * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
     10  *
     11  *
     12  *
     13  * H.264 4x4 intra prediction module
     14  *
     15  */
     16 
     17 #include "omxtypes.h"
     18 #include "armOMX.h"
     19 #include "omxVC.h"
     20 
     21 #include "armCOMM.h"
     22 #include "armVC.h"
     23 
     24 /*
     25  * Description:
     26  * Perform DC style intra prediction, averaging upper and left block
     27  *
     28  * Parameters:
     29  * [in]	pSrcLeft		Pointer to the buffer of 16 left coefficients:
     30  *								p[x, y] (x = -1, y = 0..3)
     31  * [in]	pSrcAbove		Pointer to the buffer of 16 above coefficients:
     32  *								p[x,y] (x = 0..3, y = -1)
     33  * [in]	leftStep		Step of left coefficient buffer
     34  * [in]	dstStep			Step of the destination buffer
     35  * [in]	availability	Neighboring 16x16 MB availability flag
     36  * [out]	pDst			Pointer to the destination buffer
     37  *
     38  * Return Value:
     39  * None
     40  */
     41 
     42 void armVCM4P10_PredictIntraDC4x4(
     43      const OMX_U8* pSrcLeft,
     44      const OMX_U8 *pSrcAbove,
     45      OMX_U8* pDst,
     46      OMX_INT leftStep,
     47      OMX_INT dstStep,
     48      OMX_S32 availability
     49 )
     50 {
     51     int x, y, Sum=0, Count = 0;
     52 
     53     if (availability & OMX_VC_LEFT)
     54     {
     55         for (y=0; y<4; y++)
     56         {
     57             Sum += pSrcLeft[y*leftStep];
     58         }
     59         Count++;
     60     }
     61     if (availability & OMX_VC_UPPER)
     62     {
     63         for (x=0; x<4; x++)
     64         {
     65             Sum += pSrcAbove[x];
     66         }
     67         Count++;
     68     }
     69     if (Count==0)
     70     {
     71         Sum = 128;
     72     }
     73     else if (Count==1)
     74     {
     75         Sum = (Sum + 2) >> 2;
     76     }
     77     else /* Count = 2 */
     78     {
     79         Sum = (Sum + 4) >> 3;
     80     }
     81     for (y=0; y<4; y++)
     82     {
     83         for (x=0; x<4; x++)
     84         {
     85             pDst[y*dstStep+x] = (OMX_U8)Sum;
     86         }
     87     }
     88 }
     89