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      1 /*
      2  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 
     11 
     12 #include "quant_common.h"
     13 
     14 static const int dc_qlookup[QINDEX_RANGE] =
     15 {
     16     4,    5,    6,    7,    8,    9,   10,   10,   11,   12,   13,   14,   15,   16,   17,   17,
     17     18,   19,   20,   20,   21,   21,   22,   22,   23,   23,   24,   25,   25,   26,   27,   28,
     18     29,   30,   31,   32,   33,   34,   35,   36,   37,   37,   38,   39,   40,   41,   42,   43,
     19     44,   45,   46,   46,   47,   48,   49,   50,   51,   52,   53,   54,   55,   56,   57,   58,
     20     59,   60,   61,   62,   63,   64,   65,   66,   67,   68,   69,   70,   71,   72,   73,   74,
     21     75,   76,   76,   77,   78,   79,   80,   81,   82,   83,   84,   85,   86,   87,   88,   89,
     22     91,   93,   95,   96,   98,  100,  101,  102,  104,  106,  108,  110,  112,  114,  116,  118,
     23     122,  124,  126,  128,  130,  132,  134,  136,  138,  140,  143,  145,  148,  151,  154,  157,
     24 };
     25 
     26 static const int ac_qlookup[QINDEX_RANGE] =
     27 {
     28     4,    5,    6,    7,    8,    9,   10,   11,   12,   13,   14,   15,   16,   17,   18,   19,
     29     20,   21,   22,   23,   24,   25,   26,   27,   28,   29,   30,   31,   32,   33,   34,   35,
     30     36,   37,   38,   39,   40,   41,   42,   43,   44,   45,   46,   47,   48,   49,   50,   51,
     31     52,   53,   54,   55,   56,   57,   58,   60,   62,   64,   66,   68,   70,   72,   74,   76,
     32     78,   80,   82,   84,   86,   88,   90,   92,   94,   96,   98,  100,  102,  104,  106,  108,
     33     110,  112,  114,  116,  119,  122,  125,  128,  131,  134,  137,  140,  143,  146,  149,  152,
     34     155,  158,  161,  164,  167,  170,  173,  177,  181,  185,  189,  193,  197,  201,  205,  209,
     35     213,  217,  221,  225,  229,  234,  239,  245,  249,  254,  259,  264,  269,  274,  279,  284,
     36 };
     37 
     38 
     39 int vp8_dc_quant(int QIndex, int Delta)
     40 {
     41     int retval;
     42 
     43     QIndex = QIndex + Delta;
     44 
     45     if (QIndex > 127)
     46         QIndex = 127;
     47     else if (QIndex < 0)
     48         QIndex = 0;
     49 
     50     retval = dc_qlookup[ QIndex ];
     51     return retval;
     52 }
     53 
     54 int vp8_dc2quant(int QIndex, int Delta)
     55 {
     56     int retval;
     57 
     58     QIndex = QIndex + Delta;
     59 
     60     if (QIndex > 127)
     61         QIndex = 127;
     62     else if (QIndex < 0)
     63         QIndex = 0;
     64 
     65     retval = dc_qlookup[ QIndex ] * 2;
     66     return retval;
     67 
     68 }
     69 int vp8_dc_uv_quant(int QIndex, int Delta)
     70 {
     71     int retval;
     72 
     73     QIndex = QIndex + Delta;
     74 
     75     if (QIndex > 127)
     76         QIndex = 127;
     77     else if (QIndex < 0)
     78         QIndex = 0;
     79 
     80     retval = dc_qlookup[ QIndex ];
     81 
     82     if (retval > 132)
     83         retval = 132;
     84 
     85     return retval;
     86 }
     87 
     88 int vp8_ac_yquant(int QIndex)
     89 {
     90     int retval;
     91 
     92     if (QIndex > 127)
     93         QIndex = 127;
     94     else if (QIndex < 0)
     95         QIndex = 0;
     96 
     97     retval = ac_qlookup[ QIndex ];
     98     return retval;
     99 }
    100 
    101 int vp8_ac2quant(int QIndex, int Delta)
    102 {
    103     int retval;
    104 
    105     QIndex = QIndex + Delta;
    106 
    107     if (QIndex > 127)
    108         QIndex = 127;
    109     else if (QIndex < 0)
    110         QIndex = 0;
    111 
    112     retval = (ac_qlookup[ QIndex ] * 155) / 100;
    113 
    114     if (retval < 8)
    115         retval = 8;
    116 
    117     return retval;
    118 }
    119 int vp8_ac_uv_quant(int QIndex, int Delta)
    120 {
    121     int retval;
    122 
    123     QIndex = QIndex + Delta;
    124 
    125     if (QIndex > 127)
    126         QIndex = 127;
    127     else if (QIndex < 0)
    128         QIndex = 0;
    129 
    130     retval = ac_qlookup[ QIndex ];
    131     return retval;
    132 }
    133