armVCM4P10_InterpolateHalfDiag_Luma.c revision 78e52bfac041d71ce53b5b13c2abf78af742b09d 
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
61OMXResult 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