omxVCM4P10_InvTransformDequant_LumaDC.c revision 0c1bc742181ded4930842b46e9507372f0b1b963 
1/**
2 *
3 * File Name:  omxVCM4P10_InvTransformDequant_LumaDC.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 function will calculate 4x4 hadamard transform of luma DC coefficients
13 * and quantization
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 * Function:  omxVCM4P10_InvTransformDequant_LumaDC   (6.3.5.6.3)
26 *
27 * Description:
28 * This function performs inverse 4x4 Hadamard transform and then dequantizes
29 * the coefficients.
30 *
31 * Input Arguments:
32 *
33 *   pSrc - Pointer to the 4x4 array of the 4x4 Hadamard-transformed and
34 *            quantized coefficients.  16 byte alignment required.
35 *   iQP - Quantization parameter; must be in the range [0,51].
36 *
37 * Output Arguments:
38 *
39 *   pDst - Pointer to inverse-transformed and dequantized coefficients.
40 *            16-byte alignment required.
41 *
42 * Return Value:
43 *
44 *    OMX_Sts_NoErr - no error
45 *    OMX_Sts_BadArgErr - bad arguments; returned if any of the following
46 *              conditions are true:
47 *    -    at least one of the following pointers is NULL: pSrc
48 *    -    pSrc or pDst is not aligned on a 16-byte boundary
49 *
50 */
51OMXResult omxVCM4P10_InvTransformDequant_LumaDC(
52	const OMX_S16* 	pSrc,
53	OMX_S16*	pDst,
54	OMX_U32		iQP
55)
56{
57    OMX_INT     i, j;
58    OMX_S32     m1[4][4], m2[4][4], Value;
59    OMX_S32     QPer, V;
60
61    /* check for argument error */
62    armRetArgErrIf(pSrc == NULL, OMX_Sts_BadArgErr)
63    armRetArgErrIf(pDst == NULL, OMX_Sts_BadArgErr)
64    armRetArgErrIf(iQP > 51, OMX_Sts_BadArgErr)
65    armRetArgErrIf(armNot16ByteAligned(pSrc), OMX_Sts_BadArgErr)
66    armRetArgErrIf(armNot16ByteAligned(pDst), OMX_Sts_BadArgErr)
67
68    /* Inv Hadamard Transform for DC Luma 4x4 block */
69    /* Horizontal */
70    for (i = 0; i < 4; i++)
71    {
72        j = i * 4;
73
74        m1[i][0] = pSrc[j + 0] + pSrc[j + 2]; /* a+c */
75        m1[i][1] = pSrc[j + 1] + pSrc[j + 3]; /* b+d */
76        m1[i][2] = pSrc[j + 0] - pSrc[j + 2]; /* a-c */
77        m1[i][3] = pSrc[j + 1] - pSrc[j + 3]; /* b-d */
78
79        m2[i][0] = m1[i][0] + m1[i][1]; /* a+b+c+d */
80        m2[i][1] = m1[i][2] + m1[i][3]; /* a+b-c-d */
81        m2[i][2] = m1[i][2] - m1[i][3]; /* a-b-c+d */
82        m2[i][3] = m1[i][0] - m1[i][1]; /* a-b+c-d */
83
84    }
85
86    /* Vertical */
87    for (i = 0; i < 4; i++)
88    {
89        m1[0][i] = m2[0][i] + m2[2][i];
90        m1[1][i] = m2[1][i] + m2[3][i];
91        m1[2][i] = m2[0][i] - m2[2][i];
92        m1[3][i] = m2[1][i] - m2[3][i];
93
94        m2[0][i] = m1[0][i] + m1[1][i];
95        m2[1][i] = m1[2][i] + m1[3][i];
96        m2[2][i] = m1[2][i] - m1[3][i];
97        m2[3][i] = m1[0][i] - m1[1][i];
98    }
99
100
101    /* Scaling */
102    QPer = iQP / 6;
103    V = armVCM4P10_VMatrix [iQP % 6][0];
104
105    for (j = 0; j < 4; j++)
106    {
107        for (i = 0; i < 4; i++)
108        {
109            if (QPer < 2)
110            {
111                Value = (m2[j][i] * V + (1 << (1 - QPer))) >> (2 - QPer);
112            }
113            else
114            {
115                Value = m2[j][i] * V * (1 << (QPer - 2));
116            }
117
118            pDst[j * 4 + i] = (OMX_S16) Value;
119
120        }
121    }
122    return OMX_Sts_NoErr;
123}
124
125/*****************************************************************************
126 *                              END OF FILE
127 *****************************************************************************/
128
129