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      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:  omxVCM4P2_QuantInvIntra_I.c
     20  * OpenMAX DL: v1.0.2
     21  * Revision:   9641
     22  * Date:       Thursday, February 7, 2008
     23  *
     24  *
     25  *
     26  *
     27  * Description:
     28  * Contains modules for intra inverse Quantization
     29  *
     30  */
     31 
     32 #include "omxtypes.h"
     33 #include "armOMX.h"
     34 #include "omxVC.h"
     35 
     36 #include "armCOMM.h"
     37 
     38 /**
     39  * Function:  omxVCM4P2_QuantInvIntra_I   (6.2.5.3.2)
     40  *
     41  * Description:
     42  * Performs the second inverse quantization mode on an intra/inter coded
     43  * block. Supports bits_per_pixel = 8. The output coefficients are clipped to
     44  * the range [-2048, 2047].
     45  *
     46  * Input Arguments:
     47  *
     48  *   pSrcDst - pointer to the input (quantized) intra/inter block; must be
     49  *            aligned on a 16-byte boundary.
     50  *   QP - quantization parameter (quantizer_scale)
     51  *   videoComp - video component type of the current block. Takes one of the
     52  *            following flags: OMX_VC_LUMINANCE, OMX_VC_CHROMINANCE (intra
     53  *            version only).
     54  *   shortVideoHeader - binary flag indicating presence of short_video_header
     55  *            (intra version only).
     56  *
     57  * Output Arguments:
     58  *
     59  *   pSrcDst - pointer to the output (dequantized) intra/inter block
     60  *
     61  * Return Value:
     62  *
     63  *    OMX_Sts_NoErr - no error
     64  *    OMX_Sts_BadArgErr - bad arguments; one or more of the following is
     65  *              true:
     66  *    -    pSrcDst is NULL
     67  *    -    QP <= 0 or QP >=31
     68  *    -    videoComp is neither OMX_VC_LUMINANCE nor OMX_VC_CHROMINANCE.
     69  *
     70  */
     71 
     72 OMXResult omxVCM4P2_QuantInvIntra_I(
     73      OMX_S16 * pSrcDst,
     74      OMX_INT QP,
     75      OMXVCM4P2VideoComponent videoComp,
     76 	 OMX_INT shortVideoHeader
     77 )
     78 {
     79 
     80     /* Initialized to remove compilation error */
     81     OMX_INT dcScaler = 0, coeffCount, Sign;
     82 
     83     /* Argument error checks */
     84     armRetArgErrIf(pSrcDst == NULL, OMX_Sts_BadArgErr);
     85     armRetArgErrIf(((QP <= 0) || (QP >= 32)), OMX_Sts_BadArgErr);
     86 	armRetArgErrIf(((videoComp != OMX_VC_LUMINANCE) && (videoComp != OMX_VC_CHROMINANCE)), OMX_Sts_BadArgErr);
     87 
     88     /* Calculate the DC scaler value */
     89 
     90     /* linear intra DC mode */
     91     if(shortVideoHeader)
     92     {
     93         dcScaler = 8;
     94     }
     95     /* nonlinear intra DC mode */
     96     else
     97     {
     98 
     99         if (videoComp == OMX_VC_LUMINANCE)
    100         {
    101             if (QP >= 1 && QP <= 4)
    102             {
    103                 dcScaler = 8;
    104             }
    105             else if (QP >= 5 && QP <= 8)
    106             {
    107                 dcScaler = 2 * QP;
    108             }
    109             else if (QP >= 9 && QP <= 24)
    110             {
    111                 dcScaler = QP + 8;
    112             }
    113             else
    114             {
    115                 dcScaler = (2 * QP) - 16;
    116             }
    117         }
    118 
    119         else if (videoComp == OMX_VC_CHROMINANCE)
    120         {
    121             if (QP >= 1 && QP <= 4)
    122             {
    123                 dcScaler = 8;
    124             }
    125             else if (QP >= 5 && QP <= 24)
    126             {
    127                 dcScaler = (QP + 13)/2;
    128             }
    129             else
    130             {
    131                 dcScaler = QP - 6;
    132             }
    133         }
    134     }
    135     /* Dequant the DC value, this applies to both the methods */
    136     pSrcDst[0] = pSrcDst[0] * dcScaler;
    137 
    138     /* Saturate */
    139     pSrcDst[0] = armClip (-2048, 2047, pSrcDst[0]);
    140 
    141     /* Second Inverse quantisation method */
    142     for (coeffCount = 1; coeffCount < 64; coeffCount++)
    143     {
    144         /* check sign */
    145         Sign =  armSignCheck (pSrcDst[coeffCount]);
    146 
    147         if (QP & 0x1)
    148         {
    149             pSrcDst[coeffCount] = (2* armAbs(pSrcDst[coeffCount]) + 1) * QP;
    150             pSrcDst[coeffCount] *= Sign;
    151         }
    152         else
    153         {
    154             pSrcDst[coeffCount] =
    155                                 (2* armAbs(pSrcDst[coeffCount]) + 1) * QP - 1;
    156             pSrcDst[coeffCount] *= Sign;
    157         }
    158 
    159         /* Saturate */
    160         pSrcDst[coeffCount] = armClip (-2048, 2047, pSrcDst[coeffCount]);
    161     }
    162     return OMX_Sts_NoErr;
    163 
    164 }
    165 
    166 /* End of file */
    167 
    168 
    169