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