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| 1 : | Isibaar | 1.1 | /************************************************************************** |
| 2 : | * | ||
| 3 : | * XVID MPEG-4 VIDEO CODEC | ||
| 4 : | edgomez | 1.4 | * - quantization/dequantization - |
| 5 : | Isibaar | 1.1 | * |
| 6 : | edgomez | 1.4 | * This file is part of XviD, a free MPEG-4 video encoder/decoder |
| 7 : | * | ||
| 8 : | * XviD is free software; you can redistribute it and/or modify it | ||
| 9 : | * under the terms of the GNU General Public License as published by | ||
| 10 : | * the Free Software Foundation; either version 2 of the License, or | ||
| 11 : | * (at your option) any later version. | ||
| 12 : | * | ||
| 13 : | * This program is distributed in the hope that it will be useful, | ||
| 14 : | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 15 : | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 16 : | * GNU General Public License for more details. | ||
| 17 : | * | ||
| 18 : | * You should have received a copy of the GNU General Public License | ||
| 19 : | * along with this program; if not, write to the Free Software | ||
| 20 : | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
| 21 : | * | ||
| 22 : | * Under section 8 of the GNU General Public License, the copyright | ||
| 23 : | * holders of XVID explicitly forbid distribution in the following | ||
| 24 : | * countries: | ||
| 25 : | * | ||
| 26 : | * - Japan | ||
| 27 : | * - United States of America | ||
| 28 : | * | ||
| 29 : | * Linking XviD statically or dynamically with other modules is making a | ||
| 30 : | * combined work based on XviD. Thus, the terms and conditions of the | ||
| 31 : | * GNU General Public License cover the whole combination. | ||
| 32 : | * | ||
| 33 : | * As a special exception, the copyright holders of XviD give you | ||
| 34 : | * permission to link XviD with independent modules that communicate with | ||
| 35 : | * XviD solely through the VFW1.1 and DShow interfaces, regardless of the | ||
| 36 : | * license terms of these independent modules, and to copy and distribute | ||
| 37 : | * the resulting combined work under terms of your choice, provided that | ||
| 38 : | * every copy of the combined work is accompanied by a complete copy of | ||
| 39 : | * the source code of XviD (the version of XviD used to produce the | ||
| 40 : | * combined work), being distributed under the terms of the GNU General | ||
| 41 : | * Public License plus this exception. An independent module is a module | ||
| 42 : | * which is not derived from or based on XviD. | ||
| 43 : | * | ||
| 44 : | * Note that people who make modified versions of XviD are not obligated | ||
| 45 : | * to grant this special exception for their modified versions; it is | ||
| 46 : | * their choice whether to do so. The GNU General Public License gives | ||
| 47 : | * permission to release a modified version without this exception; this | ||
| 48 : | * exception also makes it possible to release a modified version which | ||
| 49 : | * carries forward this exception. | ||
| 50 : | * | ||
| 51 : | * $Id$ | ||
| 52 : | Isibaar | 1.1 | * |
| 53 : | *************************************************************************/ | ||
| 54 : | |||
| 55 : | #include "quant_h263.h" | ||
| 56 : | |||
| 57 : | /* mutliply+shift division table | ||
| 58 : | */ | ||
| 59 : | |||
| 60 : | #define SCALEBITS 16 | ||
| 61 : | #define FIX(X) ((1L << SCALEBITS) / (X) + 1) | ||
| 62 : | |||
| 63 : | edgomez | 1.2 | static const uint32_t multipliers[32] = { |
| 64 : | 0, FIX(2), FIX(4), FIX(6), | ||
| 65 : | FIX(8), FIX(10), FIX(12), FIX(14), | ||
| 66 : | FIX(16), FIX(18), FIX(20), FIX(22), | ||
| 67 : | FIX(24), FIX(26), FIX(28), FIX(30), | ||
| 68 : | FIX(32), FIX(34), FIX(36), FIX(38), | ||
| 69 : | FIX(40), FIX(42), FIX(44), FIX(46), | ||
| 70 : | FIX(48), FIX(50), FIX(52), FIX(54), | ||
| 71 : | FIX(56), FIX(58), FIX(60), FIX(62) | ||
| 72 : | }; | ||
| 73 : | Isibaar | 1.1 | |
| 74 : | |||
| 75 : | |||
| 76 : | #define DIV_DIV(a, b) ((a)>0) ? ((a)+((b)>>1))/(b) : ((a)-((b)>>1))/(b) | ||
| 77 : | |||
| 78 : | // function pointers | ||
| 79 : | quanth263_intraFuncPtr quant_intra; | ||
| 80 : | quanth263_intraFuncPtr dequant_intra; | ||
| 81 : | |||
| 82 : | quanth263_interFuncPtr quant_inter; | ||
| 83 : | dequanth263_interFuncPtr dequant_inter; | ||
| 84 : | |||
| 85 : | |||
| 86 : | |||
| 87 : | /* quantize intra-block | ||
| 88 : | */ | ||
| 89 : | |||
| 90 : | |||
| 91 : | edgomez | 1.2 | void |
| 92 : | quant_intra_c(int16_t * coeff, | ||
| 93 : | const int16_t * data, | ||
| 94 : | const uint32_t quant, | ||
| 95 : | const uint32_t dcscalar) | ||
| 96 : | Isibaar | 1.1 | { |
| 97 : | const uint32_t mult = multipliers[quant]; | ||
| 98 : | const uint16_t quant_m_2 = quant << 1; | ||
| 99 : | edgomez | 1.2 | uint32_t i; |
| 100 : | Isibaar | 1.1 | |
| 101 : | edgomez | 1.2 | coeff[0] = DIV_DIV(data[0], (int32_t) dcscalar); |
| 102 : | Isibaar | 1.1 | |
| 103 : | for (i = 1; i < 64; i++) { | ||
| 104 : | int16_t acLevel = data[i]; | ||
| 105 : | |||
| 106 : | if (acLevel < 0) { | ||
| 107 : | acLevel = -acLevel; | ||
| 108 : | if (acLevel < quant_m_2) { | ||
| 109 : | coeff[i] = 0; | ||
| 110 : | continue; | ||
| 111 : | } | ||
| 112 : | acLevel = (acLevel * mult) >> SCALEBITS; | ||
| 113 : | coeff[i] = -acLevel; | ||
| 114 : | } else { | ||
| 115 : | if (acLevel < quant_m_2) { | ||
| 116 : | coeff[i] = 0; | ||
| 117 : | continue; | ||
| 118 : | } | ||
| 119 : | acLevel = (acLevel * mult) >> SCALEBITS; | ||
| 120 : | coeff[i] = acLevel; | ||
| 121 : | } | ||
| 122 : | } | ||
| 123 : | } | ||
| 124 : | |||
| 125 : | |||
| 126 : | /* quantize inter-block | ||
| 127 : | */ | ||
| 128 : | |||
| 129 : | edgomez | 1.2 | uint32_t |
| 130 : | quant_inter_c(int16_t * coeff, | ||
| 131 : | const int16_t * data, | ||
| 132 : | const uint32_t quant) | ||
| 133 : | Isibaar | 1.1 | { |
| 134 : | const uint32_t mult = multipliers[quant]; | ||
| 135 : | const uint16_t quant_m_2 = quant << 1; | ||
| 136 : | const uint16_t quant_d_2 = quant >> 1; | ||
| 137 : | int sum = 0; | ||
| 138 : | uint32_t i; | ||
| 139 : | |||
| 140 : | for (i = 0; i < 64; i++) { | ||
| 141 : | int16_t acLevel = data[i]; | ||
| 142 : | edgomez | 1.2 | |
| 143 : | Isibaar | 1.1 | if (acLevel < 0) { |
| 144 : | acLevel = (-acLevel) - quant_d_2; | ||
| 145 : | if (acLevel < quant_m_2) { | ||
| 146 : | coeff[i] = 0; | ||
| 147 : | continue; | ||
| 148 : | } | ||
| 149 : | |||
| 150 : | acLevel = (acLevel * mult) >> SCALEBITS; | ||
| 151 : | sum += acLevel; // sum += |acLevel| | ||
| 152 : | coeff[i] = -acLevel; | ||
| 153 : | } else { | ||
| 154 : | acLevel -= quant_d_2; | ||
| 155 : | if (acLevel < quant_m_2) { | ||
| 156 : | coeff[i] = 0; | ||
| 157 : | continue; | ||
| 158 : | } | ||
| 159 : | acLevel = (acLevel * mult) >> SCALEBITS; | ||
| 160 : | sum += acLevel; | ||
| 161 : | coeff[i] = acLevel; | ||
| 162 : | } | ||
| 163 : | } | ||
| 164 : | |||
| 165 : | return sum; | ||
| 166 : | } | ||
| 167 : | |||
| 168 : | |||
| 169 : | /* dequantize intra-block & clamp to [-2048,2047] | ||
| 170 : | */ | ||
| 171 : | |||
| 172 : | edgomez | 1.2 | void |
| 173 : | dequant_intra_c(int16_t * data, | ||
| 174 : | const int16_t * coeff, | ||
| 175 : | const uint32_t quant, | ||
| 176 : | const uint32_t dcscalar) | ||
| 177 : | Isibaar | 1.1 | { |
| 178 : | const int32_t quant_m_2 = quant << 1; | ||
| 179 : | const int32_t quant_add = (quant & 1 ? quant : quant - 1); | ||
| 180 : | edgomez | 1.2 | uint32_t i; |
| 181 : | Isibaar | 1.1 | |
| 182 : | edgomez | 1.2 | data[0] = coeff[0] * dcscalar; |
| 183 : | if (data[0] < -2048) { | ||
| 184 : | Isibaar | 1.1 | data[0] = -2048; |
| 185 : | edgomez | 1.2 | } else if (data[0] > 2047) { |
| 186 : | Isibaar | 1.1 | data[0] = 2047; |
| 187 : | } | ||
| 188 : | |||
| 189 : | |||
| 190 : | for (i = 1; i < 64; i++) { | ||
| 191 : | int32_t acLevel = coeff[i]; | ||
| 192 : | edgomez | 1.2 | |
| 193 : | if (acLevel == 0) { | ||
| 194 : | Isibaar | 1.1 | data[i] = 0; |
| 195 : | edgomez | 1.2 | } else if (acLevel < 0) { |
| 196 : | Isibaar | 1.1 | acLevel = quant_m_2 * -acLevel + quant_add; |
| 197 : | data[i] = (acLevel <= 2048 ? -acLevel : -2048); | ||
| 198 : | edgomez | 1.2 | } else // if (acLevel > 0) { |
| 199 : | { | ||
| 200 : | Isibaar | 1.1 | acLevel = quant_m_2 * acLevel + quant_add; |
| 201 : | data[i] = (acLevel <= 2047 ? acLevel : 2047); | ||
| 202 : | } | ||
| 203 : | } | ||
| 204 : | } | ||
| 205 : | |||
| 206 : | |||
| 207 : | |||
| 208 : | /* dequantize inter-block & clamp to [-2048,2047] | ||
| 209 : | */ | ||
| 210 : | |||
| 211 : | edgomez | 1.2 | void |
| 212 : | dequant_inter_c(int16_t * data, | ||
| 213 : | const int16_t * coeff, | ||
| 214 : | const uint32_t quant) | ||
| 215 : | Isibaar | 1.1 | { |
| 216 : | const uint16_t quant_m_2 = quant << 1; | ||
| 217 : | const uint16_t quant_add = (quant & 1 ? quant : quant - 1); | ||
| 218 : | uint32_t i; | ||
| 219 : | |||
| 220 : | for (i = 0; i < 64; i++) { | ||
| 221 : | int16_t acLevel = coeff[i]; | ||
| 222 : | edgomez | 1.2 | |
| 223 : | if (acLevel == 0) { | ||
| 224 : | Isibaar | 1.1 | data[i] = 0; |
| 225 : | edgomez | 1.2 | } else if (acLevel < 0) { |
| 226 : | Isibaar | 1.1 | acLevel = acLevel * quant_m_2 - quant_add; |
| 227 : | data[i] = (acLevel >= -2048 ? acLevel : -2048); | ||
| 228 : | edgomez | 1.2 | } else // if (acLevel > 0) |
| 229 : | { | ||
| 230 : | Isibaar | 1.1 | acLevel = acLevel * quant_m_2 + quant_add; |
| 231 : | data[i] = (acLevel <= 2047 ? acLevel : 2047); | ||
| 232 : | } | ||
| 233 : | } | ||
| 234 : | } |
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