1/**
2 *
3 * File Name:  omxVCM4P2_QuantInvIntra_I.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 *
12 * Description:
13 * Contains modules for intra inverse Quantization
14 *
15 */
16
17#include "omxtypes.h"
18#include "armOMX.h"
19#include "omxVC.h"
20
21#include "armCOMM.h"
22
23/**
24 * Function:  omxVCM4P2_QuantInvIntra_I   (6.2.5.3.2)
25 *
26 * Description:
27 * Performs the second inverse quantization mode on an intra/inter coded
28 * block. Supports bits_per_pixel = 8. The output coefficients are clipped to
29 * the range [-2048, 2047].
30 *
31 * Input Arguments:
32 *
33 *   pSrcDst - pointer to the input (quantized) intra/inter block; must be
34 *            aligned on a 16-byte boundary.
35 *   QP - quantization parameter (quantizer_scale)
36 *   videoComp - video component type of the current block. Takes one of the
37 *            following flags: OMX_VC_LUMINANCE, OMX_VC_CHROMINANCE (intra
38 *            version only).
39 *   shortVideoHeader - binary flag indicating presence of short_video_header
40 *            (intra version only).
41 *
42 * Output Arguments:
43 *
44 *   pSrcDst - pointer to the output (dequantized) intra/inter block
45 *
46 * Return Value:
47 *
48 *    OMX_Sts_NoErr - no error
49 *    OMX_Sts_BadArgErr - bad arguments; one or more of the following is
50 *              true:
51 *    -    pSrcDst is NULL
52 *    -    QP <= 0 or QP >=31
53 *    -    videoComp is neither OMX_VC_LUMINANCE nor OMX_VC_CHROMINANCE.
54 *
55 */
56
57OMXResult omxVCM4P2_QuantInvIntra_I(
58     OMX_S16 * pSrcDst,
59     OMX_INT QP,
60     OMXVCM4P2VideoComponent videoComp,
61	 OMX_INT shortVideoHeader
62)
63{
64
65    /* Initialized to remove compilation error */
66    OMX_INT dcScaler = 0, coeffCount, Sign;
67
68    /* Argument error checks */
69    armRetArgErrIf(pSrcDst == NULL, OMX_Sts_BadArgErr);
70    armRetArgErrIf(((QP <= 0) || (QP >= 32)), OMX_Sts_BadArgErr);
71	armRetArgErrIf(((videoComp != OMX_VC_LUMINANCE) && (videoComp != OMX_VC_CHROMINANCE)), OMX_Sts_BadArgErr);
72
73    /* Calculate the DC scaler value */
74
75    /* linear intra DC mode */
76    if(shortVideoHeader)
77    {
78        dcScaler = 8;
79    }
80    /* nonlinear intra DC mode */
81    else
82    {
83
84        if (videoComp == OMX_VC_LUMINANCE)
85        {
86            if (QP >= 1 && QP <= 4)
87            {
88                dcScaler = 8;
89            }
90            else if (QP >= 5 && QP <= 8)
91            {
92                dcScaler = 2 * QP;
93            }
94            else if (QP >= 9 && QP <= 24)
95            {
96                dcScaler = QP + 8;
97            }
98            else
99            {
100                dcScaler = (2 * QP) - 16;
101            }
102        }
103
104        else if (videoComp == OMX_VC_CHROMINANCE)
105        {
106            if (QP >= 1 && QP <= 4)
107            {
108                dcScaler = 8;
109            }
110            else if (QP >= 5 && QP <= 24)
111            {
112                dcScaler = (QP + 13)/2;
113            }
114            else
115            {
116                dcScaler = QP - 6;
117            }
118        }
119    }
120    /* Dequant the DC value, this applies to both the methods */
121    pSrcDst[0] = pSrcDst[0] * dcScaler;
122
123    /* Saturate */
124    pSrcDst[0] = armClip (-2048, 2047, pSrcDst[0]);
125
126    /* Second Inverse quantisation method */
127    for (coeffCount = 1; coeffCount < 64; coeffCount++)
128    {
129        /* check sign */
130        Sign =  armSignCheck (pSrcDst[coeffCount]);
131
132        if (QP & 0x1)
133        {
134            pSrcDst[coeffCount] = (2* armAbs(pSrcDst[coeffCount]) + 1) * QP;
135            pSrcDst[coeffCount] *= Sign;
136        }
137        else
138        {
139            pSrcDst[coeffCount] =
140                                (2* armAbs(pSrcDst[coeffCount]) + 1) * QP - 1;
141            pSrcDst[coeffCount] *= Sign;
142        }
143
144        /* Saturate */
145        pSrcDst[coeffCount] = armClip (-2048, 2047, pSrcDst[coeffCount]);
146    }
147    return OMX_Sts_NoErr;
148
149}
150
151/* End of file */
152
153
154