xref: /aosp_15_r20/external/libvpx/vp8/common/quant_common.c (revision fb1b10ab9aebc7c7068eedab379b749d7e3900be)
1*fb1b10abSAndroid Build Coastguard Worker /*
2*fb1b10abSAndroid Build Coastguard Worker  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3*fb1b10abSAndroid Build Coastguard Worker  *
4*fb1b10abSAndroid Build Coastguard Worker  *  Use of this source code is governed by a BSD-style license
5*fb1b10abSAndroid Build Coastguard Worker  *  that can be found in the LICENSE file in the root of the source
6*fb1b10abSAndroid Build Coastguard Worker  *  tree. An additional intellectual property rights grant can be found
7*fb1b10abSAndroid Build Coastguard Worker  *  in the file PATENTS.  All contributing project authors may
8*fb1b10abSAndroid Build Coastguard Worker  *  be found in the AUTHORS file in the root of the source tree.
9*fb1b10abSAndroid Build Coastguard Worker  */
10*fb1b10abSAndroid Build Coastguard Worker 
11*fb1b10abSAndroid Build Coastguard Worker #include "quant_common.h"
12*fb1b10abSAndroid Build Coastguard Worker 
13*fb1b10abSAndroid Build Coastguard Worker static const int dc_qlookup[QINDEX_RANGE] = {
14*fb1b10abSAndroid Build Coastguard Worker   4,   5,   6,   7,   8,   9,   10,  10,  11,  12,  13,  14,  15,  16,  17,
15*fb1b10abSAndroid Build Coastguard Worker   17,  18,  19,  20,  20,  21,  21,  22,  22,  23,  23,  24,  25,  25,  26,
16*fb1b10abSAndroid Build Coastguard Worker   27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  37,  38,  39,  40,
17*fb1b10abSAndroid Build Coastguard Worker   41,  42,  43,  44,  45,  46,  46,  47,  48,  49,  50,  51,  52,  53,  54,
18*fb1b10abSAndroid Build Coastguard Worker   55,  56,  57,  58,  59,  60,  61,  62,  63,  64,  65,  66,  67,  68,  69,
19*fb1b10abSAndroid Build Coastguard Worker   70,  71,  72,  73,  74,  75,  76,  76,  77,  78,  79,  80,  81,  82,  83,
20*fb1b10abSAndroid Build Coastguard Worker   84,  85,  86,  87,  88,  89,  91,  93,  95,  96,  98,  100, 101, 102, 104,
21*fb1b10abSAndroid Build Coastguard Worker   106, 108, 110, 112, 114, 116, 118, 122, 124, 126, 128, 130, 132, 134, 136,
22*fb1b10abSAndroid Build Coastguard Worker   138, 140, 143, 145, 148, 151, 154, 157,
23*fb1b10abSAndroid Build Coastguard Worker };
24*fb1b10abSAndroid Build Coastguard Worker 
25*fb1b10abSAndroid Build Coastguard Worker static const int ac_qlookup[QINDEX_RANGE] = {
26*fb1b10abSAndroid Build Coastguard Worker   4,   5,   6,   7,   8,   9,   10,  11,  12,  13,  14,  15,  16,  17,  18,
27*fb1b10abSAndroid Build Coastguard Worker   19,  20,  21,  22,  23,  24,  25,  26,  27,  28,  29,  30,  31,  32,  33,
28*fb1b10abSAndroid Build Coastguard Worker   34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
29*fb1b10abSAndroid Build Coastguard Worker   49,  50,  51,  52,  53,  54,  55,  56,  57,  58,  60,  62,  64,  66,  68,
30*fb1b10abSAndroid Build Coastguard Worker   70,  72,  74,  76,  78,  80,  82,  84,  86,  88,  90,  92,  94,  96,  98,
31*fb1b10abSAndroid Build Coastguard Worker   100, 102, 104, 106, 108, 110, 112, 114, 116, 119, 122, 125, 128, 131, 134,
32*fb1b10abSAndroid Build Coastguard Worker   137, 140, 143, 146, 149, 152, 155, 158, 161, 164, 167, 170, 173, 177, 181,
33*fb1b10abSAndroid Build Coastguard Worker   185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 234, 239, 245,
34*fb1b10abSAndroid Build Coastguard Worker   249, 254, 259, 264, 269, 274, 279, 284,
35*fb1b10abSAndroid Build Coastguard Worker };
36*fb1b10abSAndroid Build Coastguard Worker 
vp8_dc_quant(int QIndex,int Delta)37*fb1b10abSAndroid Build Coastguard Worker int vp8_dc_quant(int QIndex, int Delta) {
38*fb1b10abSAndroid Build Coastguard Worker   int retval;
39*fb1b10abSAndroid Build Coastguard Worker 
40*fb1b10abSAndroid Build Coastguard Worker   QIndex = QIndex + Delta;
41*fb1b10abSAndroid Build Coastguard Worker 
42*fb1b10abSAndroid Build Coastguard Worker   if (QIndex > 127) {
43*fb1b10abSAndroid Build Coastguard Worker     QIndex = 127;
44*fb1b10abSAndroid Build Coastguard Worker   } else if (QIndex < 0) {
45*fb1b10abSAndroid Build Coastguard Worker     QIndex = 0;
46*fb1b10abSAndroid Build Coastguard Worker   }
47*fb1b10abSAndroid Build Coastguard Worker 
48*fb1b10abSAndroid Build Coastguard Worker   retval = dc_qlookup[QIndex];
49*fb1b10abSAndroid Build Coastguard Worker   return retval;
50*fb1b10abSAndroid Build Coastguard Worker }
51*fb1b10abSAndroid Build Coastguard Worker 
vp8_dc2quant(int QIndex,int Delta)52*fb1b10abSAndroid Build Coastguard Worker int vp8_dc2quant(int QIndex, int Delta) {
53*fb1b10abSAndroid Build Coastguard Worker   int retval;
54*fb1b10abSAndroid Build Coastguard Worker 
55*fb1b10abSAndroid Build Coastguard Worker   QIndex = QIndex + Delta;
56*fb1b10abSAndroid Build Coastguard Worker 
57*fb1b10abSAndroid Build Coastguard Worker   if (QIndex > 127) {
58*fb1b10abSAndroid Build Coastguard Worker     QIndex = 127;
59*fb1b10abSAndroid Build Coastguard Worker   } else if (QIndex < 0) {
60*fb1b10abSAndroid Build Coastguard Worker     QIndex = 0;
61*fb1b10abSAndroid Build Coastguard Worker   }
62*fb1b10abSAndroid Build Coastguard Worker 
63*fb1b10abSAndroid Build Coastguard Worker   retval = dc_qlookup[QIndex] * 2;
64*fb1b10abSAndroid Build Coastguard Worker   return retval;
65*fb1b10abSAndroid Build Coastguard Worker }
vp8_dc_uv_quant(int QIndex,int Delta)66*fb1b10abSAndroid Build Coastguard Worker int vp8_dc_uv_quant(int QIndex, int Delta) {
67*fb1b10abSAndroid Build Coastguard Worker   int retval;
68*fb1b10abSAndroid Build Coastguard Worker 
69*fb1b10abSAndroid Build Coastguard Worker   QIndex = QIndex + Delta;
70*fb1b10abSAndroid Build Coastguard Worker 
71*fb1b10abSAndroid Build Coastguard Worker   if (QIndex > 127) {
72*fb1b10abSAndroid Build Coastguard Worker     QIndex = 127;
73*fb1b10abSAndroid Build Coastguard Worker   } else if (QIndex < 0) {
74*fb1b10abSAndroid Build Coastguard Worker     QIndex = 0;
75*fb1b10abSAndroid Build Coastguard Worker   }
76*fb1b10abSAndroid Build Coastguard Worker 
77*fb1b10abSAndroid Build Coastguard Worker   retval = dc_qlookup[QIndex];
78*fb1b10abSAndroid Build Coastguard Worker 
79*fb1b10abSAndroid Build Coastguard Worker   if (retval > 132) retval = 132;
80*fb1b10abSAndroid Build Coastguard Worker 
81*fb1b10abSAndroid Build Coastguard Worker   return retval;
82*fb1b10abSAndroid Build Coastguard Worker }
83*fb1b10abSAndroid Build Coastguard Worker 
vp8_ac_yquant(int QIndex)84*fb1b10abSAndroid Build Coastguard Worker int vp8_ac_yquant(int QIndex) {
85*fb1b10abSAndroid Build Coastguard Worker   int retval;
86*fb1b10abSAndroid Build Coastguard Worker 
87*fb1b10abSAndroid Build Coastguard Worker   if (QIndex > 127) {
88*fb1b10abSAndroid Build Coastguard Worker     QIndex = 127;
89*fb1b10abSAndroid Build Coastguard Worker   } else if (QIndex < 0) {
90*fb1b10abSAndroid Build Coastguard Worker     QIndex = 0;
91*fb1b10abSAndroid Build Coastguard Worker   }
92*fb1b10abSAndroid Build Coastguard Worker 
93*fb1b10abSAndroid Build Coastguard Worker   retval = ac_qlookup[QIndex];
94*fb1b10abSAndroid Build Coastguard Worker   return retval;
95*fb1b10abSAndroid Build Coastguard Worker }
96*fb1b10abSAndroid Build Coastguard Worker 
vp8_ac2quant(int QIndex,int Delta)97*fb1b10abSAndroid Build Coastguard Worker int vp8_ac2quant(int QIndex, int Delta) {
98*fb1b10abSAndroid Build Coastguard Worker   int retval;
99*fb1b10abSAndroid Build Coastguard Worker 
100*fb1b10abSAndroid Build Coastguard Worker   QIndex = QIndex + Delta;
101*fb1b10abSAndroid Build Coastguard Worker 
102*fb1b10abSAndroid Build Coastguard Worker   if (QIndex > 127) {
103*fb1b10abSAndroid Build Coastguard Worker     QIndex = 127;
104*fb1b10abSAndroid Build Coastguard Worker   } else if (QIndex < 0) {
105*fb1b10abSAndroid Build Coastguard Worker     QIndex = 0;
106*fb1b10abSAndroid Build Coastguard Worker   }
107*fb1b10abSAndroid Build Coastguard Worker 
108*fb1b10abSAndroid Build Coastguard Worker   /* For all x in [0..284], x*155/100 is bitwise equal to (x*101581) >> 16.
109*fb1b10abSAndroid Build Coastguard Worker    * The smallest precision for that is '(x*6349) >> 12' but 16 is a good
110*fb1b10abSAndroid Build Coastguard Worker    * word size. */
111*fb1b10abSAndroid Build Coastguard Worker   retval = (ac_qlookup[QIndex] * 101581) >> 16;
112*fb1b10abSAndroid Build Coastguard Worker 
113*fb1b10abSAndroid Build Coastguard Worker   if (retval < 8) retval = 8;
114*fb1b10abSAndroid Build Coastguard Worker 
115*fb1b10abSAndroid Build Coastguard Worker   return retval;
116*fb1b10abSAndroid Build Coastguard Worker }
vp8_ac_uv_quant(int QIndex,int Delta)117*fb1b10abSAndroid Build Coastguard Worker int vp8_ac_uv_quant(int QIndex, int Delta) {
118*fb1b10abSAndroid Build Coastguard Worker   int retval;
119*fb1b10abSAndroid Build Coastguard Worker 
120*fb1b10abSAndroid Build Coastguard Worker   QIndex = QIndex + Delta;
121*fb1b10abSAndroid Build Coastguard Worker 
122*fb1b10abSAndroid Build Coastguard Worker   if (QIndex > 127) {
123*fb1b10abSAndroid Build Coastguard Worker     QIndex = 127;
124*fb1b10abSAndroid Build Coastguard Worker   } else if (QIndex < 0) {
125*fb1b10abSAndroid Build Coastguard Worker     QIndex = 0;
126*fb1b10abSAndroid Build Coastguard Worker   }
127*fb1b10abSAndroid Build Coastguard Worker 
128*fb1b10abSAndroid Build Coastguard Worker   retval = ac_qlookup[QIndex];
129*fb1b10abSAndroid Build Coastguard Worker   return retval;
130*fb1b10abSAndroid Build Coastguard Worker }
131