omxVCM4P10_TransformDequantLumaDCFromPair.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 *
20 * File Name:  omxVCM4P10_TransformDequantLumaDCFromPair.c
21 * OpenMAX DL: v1.0.2
22 * Revision:   9641
23 * Date:       Thursday, February 7, 2008
24 *
25 *
26 *
27 *
28 * H.264 inverse quantize and transform module
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 * Description:
41 * Dequantize Luma DC block
42 */
43
44static void DequantLumaDC4x4(
45     OMX_S16* pDst,
46     OMX_INT QP
47)
48{
49    int Shift = (QP/6)-2 ;
50    int Scale = armVCM4P10_VMatrix[QP%6][0];
51    int i, Round, Value;
52
53    if (Shift >= 0)
54    {
55        for (i=0; i<16; i++)
56        {
57            Value = (pDst[i] * Scale) << Shift;
58            pDst[i] = (OMX_S16)Value;
59        }
60    }
61    else
62    {
63        Shift = -Shift;;
64        Round = 1<<(Shift-1);
65
66        for (i=0; i<16; i++)
67        {
68            Value = (pDst[i] * Scale + Round) >> Shift;
69            pDst[i] = (OMX_S16)Value;
70        }
71    }
72}
73
74
75
76/*
77 * Description:
78 * Inverse Transform DC 4x4 Coefficients
79 */
80static void InvTransformDC4x4(OMX_S16* pData)
81{
82    int i;
83
84    /* Transform rows */
85    for (i=0; i<16; i+=4)
86    {
87        int c0 = pData[i+0];
88        int c1 = pData[i+1];
89        int c2 = pData[i+2];
90        int c3 = pData[i+3];
91        pData[i+0] = (OMX_S16)(c0+c1+c2+c3);
92        pData[i+1] = (OMX_S16)(c0+c1-c2-c3);
93        pData[i+2] = (OMX_S16)(c0-c1-c2+c3);
94        pData[i+3] = (OMX_S16)(c0-c1+c2-c3);
95    }
96
97    /* Transform columns */
98    for (i=0; i<4; i++)
99    {
100        int c0 = pData[i+0];
101        int c1 = pData[i+4];
102        int c2 = pData[i+8];
103        int c3 = pData[i+12];
104        pData[i+0] = (OMX_S16)(c0+c1+c2+c3);
105        pData[i+4] = (OMX_S16)(c0+c1-c2-c3);
106        pData[i+8] = (OMX_S16)(c0-c1-c2+c3);
107        pData[i+12] = (OMX_S16)(c0-c1+c2-c3);
108    }
109}
110
111
112/**
113 * Function:  omxVCM4P10_TransformDequantLumaDCFromPair   (6.3.4.2.1)
114 *
115 * Description:
116 * Reconstructs the 4x4 LumaDC block from the coefficient-position pair
117 * buffer, performs integer inverse, and dequantization for 4x4 LumaDC
118 * coefficients, and updates the pair buffer pointer to the next non-empty
119 * block.
120 *
121 * Input Arguments:
122 *
123 *   ppSrc - Double pointer to residual coefficient-position pair buffer
124 *            output by CALVC decoding
125 *   QP - Quantization parameter QpY
126 *
127 * Output Arguments:
128 *
129 *   ppSrc - *ppSrc is updated to the start of next non empty block
130 *   pDst - Pointer to the reconstructed 4x4 LumaDC coefficients buffer; must
131 *            be aligned on a 8-byte boundary.
132 *
133 * Return Value:
134 *    OMX_Sts_NoErr, if the function runs without error.
135 *    OMX_Sts_BadArgErr - bad arguments: if one of the following cases occurs:
136 *    -    ppSrc or pDst is NULL.
137 *    -    pDst is not 8 byte aligned.
138 *    -    QP is not in the range of [0-51].
139 *
140 */
141
142OMXResult omxVCM4P10_TransformDequantLumaDCFromPair(
143     const OMX_U8 **ppSrc,
144     OMX_S16* pDst,
145     OMX_INT QP
146 )
147{
148    armRetArgErrIf(ppSrc  == NULL,           OMX_Sts_BadArgErr);
149    armRetArgErrIf(*ppSrc == NULL,           OMX_Sts_BadArgErr);
150    armRetArgErrIf(pDst   == NULL,           OMX_Sts_BadArgErr);
151    armRetArgErrIf(armNot8ByteAligned(pDst), OMX_Sts_BadArgErr);
152    armRetArgErrIf(QP<0,                     OMX_Sts_BadArgErr);
153    armRetArgErrIf(QP>51,                    OMX_Sts_BadArgErr);
154
155    armVCM4P10_UnpackBlock4x4(ppSrc, pDst);
156    /*InvTransformDequantLumaDC4x4(pDst, QP);*/
157    InvTransformDC4x4(pDst);
158    DequantLumaDC4x4(pDst, QP);
159
160    return OMX_Sts_NoErr;
161}
162
163/* End of file */
164