omxVCM4P10_InvTransformDequant_LumaDC.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:  omxVCM4P10_InvTransformDequant_LumaDC.c
20 * OpenMAX DL: v1.0.2
21 * Revision:   9641
22 * Date:       Thursday, February 7, 2008
23 *
24 *
25 *
26 * Description:
27 * This function will calculate 4x4 hadamard transform of luma DC coefficients
28 * and quantization
29 *
30 */
31
32#include "omxtypes.h"
33#include "armOMX.h"
34#include "omxVC.h"
35
36#include "armCOMM.h"
37#include "armVC.h"
38
39/**
40 * Function:  omxVCM4P10_InvTransformDequant_LumaDC   (6.3.5.6.3)
41 *
42 * Description:
43 * This function performs inverse 4x4 Hadamard transform and then dequantizes
44 * the coefficients.
45 *
46 * Input Arguments:
47 *
48 *   pSrc - Pointer to the 4x4 array of the 4x4 Hadamard-transformed and
49 *            quantized coefficients.  16 byte alignment required.
50 *   iQP - Quantization parameter; must be in the range [0,51].
51 *
52 * Output Arguments:
53 *
54 *   pDst - Pointer to inverse-transformed and dequantized coefficients.
55 *            16-byte alignment required.
56 *
57 * Return Value:
58 *
59 *    OMX_Sts_NoErr - no error
60 *    OMX_Sts_BadArgErr - bad arguments; returned if any of the following
61 *              conditions are true:
62 *    -    at least one of the following pointers is NULL: pSrc
63 *    -    pSrc or pDst is not aligned on a 16-byte boundary
64 *
65 */
66OMXResult omxVCM4P10_InvTransformDequant_LumaDC(
67	const OMX_S16* 	pSrc,
68	OMX_S16*	pDst,
69	OMX_U32		iQP
70)
71{
72    OMX_INT     i, j;
73    OMX_S32     m1[4][4], m2[4][4], Value;
74    OMX_S32     QPer, V;
75
76    /* check for argument error */
77    armRetArgErrIf(pSrc == NULL, OMX_Sts_BadArgErr)
78    armRetArgErrIf(pDst == NULL, OMX_Sts_BadArgErr)
79    armRetArgErrIf(iQP > 51, OMX_Sts_BadArgErr)
80    armRetArgErrIf(armNot16ByteAligned(pSrc), OMX_Sts_BadArgErr)
81    armRetArgErrIf(armNot16ByteAligned(pDst), OMX_Sts_BadArgErr)
82
83    /* Inv Hadamard Transform for DC Luma 4x4 block */
84    /* Horizontal */
85    for (i = 0; i < 4; i++)
86    {
87        j = i * 4;
88
89        m1[i][0] = pSrc[j + 0] + pSrc[j + 2]; /* a+c */
90        m1[i][1] = pSrc[j + 1] + pSrc[j + 3]; /* b+d */
91        m1[i][2] = pSrc[j + 0] - pSrc[j + 2]; /* a-c */
92        m1[i][3] = pSrc[j + 1] - pSrc[j + 3]; /* b-d */
93
94        m2[i][0] = m1[i][0] + m1[i][1]; /* a+b+c+d */
95        m2[i][1] = m1[i][2] + m1[i][3]; /* a+b-c-d */
96        m2[i][2] = m1[i][2] - m1[i][3]; /* a-b-c+d */
97        m2[i][3] = m1[i][0] - m1[i][1]; /* a-b+c-d */
98
99    }
100
101    /* Vertical */
102    for (i = 0; i < 4; i++)
103    {
104        m1[0][i] = m2[0][i] + m2[2][i];
105        m1[1][i] = m2[1][i] + m2[3][i];
106        m1[2][i] = m2[0][i] - m2[2][i];
107        m1[3][i] = m2[1][i] - m2[3][i];
108
109        m2[0][i] = m1[0][i] + m1[1][i];
110        m2[1][i] = m1[2][i] + m1[3][i];
111        m2[2][i] = m1[2][i] - m1[3][i];
112        m2[3][i] = m1[0][i] - m1[1][i];
113    }
114
115
116    /* Scaling */
117    QPer = iQP / 6;
118    V = armVCM4P10_VMatrix [iQP % 6][0];
119
120    for (j = 0; j < 4; j++)
121    {
122        for (i = 0; i < 4; i++)
123        {
124            if (QPer < 2)
125            {
126                Value = (m2[j][i] * V + (1 << (1 - QPer))) >> (2 - QPer);
127            }
128            else
129            {
130                Value = m2[j][i] * V * (1 << (QPer - 2));
131            }
132
133            pDst[j * 4 + i] = (OMX_S16) Value;
134
135        }
136    }
137    return OMX_Sts_NoErr;
138}
139
140/*****************************************************************************
141 *                              END OF FILE
142 *****************************************************************************/
143
144