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 /* For all x in [0..284], x*155/100 is bitwise equal to (x*101581) >> 16. 113 * The smallest precision for that is '(x*6349) >> 12' but 16 is a good 114 * word size. */ 115 retval = (ac_qlookup[ QIndex ] * 101581) >> 16; 116 117 if (retval < 8) 118 retval = 8; 119 120 return retval; 121 } 122 int vp8_ac_uv_quant(int QIndex, int Delta) 123 { 124 int retval; 125 126 QIndex = QIndex + Delta; 127 128 if (QIndex > 127) 129 QIndex = 127; 130 else if (QIndex < 0) 131 QIndex = 0; 132 133 retval = ac_qlookup[ QIndex ]; 134 return retval; 135 } 136
