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comparison: media/libjpeg/jddctmgr.c
media/libjpeg/jddctmgr.c
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- TOR_BUG_9701
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| -1:000000000000 | 0:2d00e926cd10 |
|---|---|
| 1 /* | |
| 2 * jddctmgr.c | |
| 3 * | |
| 4 * This file was part of the Independent JPEG Group's software: | |
| 5 * Copyright (C) 1994-1996, Thomas G. Lane. | |
| 6 * Modified 2002-2010 by Guido Vollbeding. | |
| 7 * libjpeg-turbo Modifications: | |
| 8 * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB | |
| 9 * Copyright (C) 2010, D. R. Commander. | |
| 10 * For conditions of distribution and use, see the accompanying README file. | |
| 11 * | |
| 12 * This file contains the inverse-DCT management logic. | |
| 13 * This code selects a particular IDCT implementation to be used, | |
| 14 * and it performs related housekeeping chores. No code in this file | |
| 15 * is executed per IDCT step, only during output pass setup. | |
| 16 * | |
| 17 * Note that the IDCT routines are responsible for performing coefficient | |
| 18 * dequantization as well as the IDCT proper. This module sets up the | |
| 19 * dequantization multiplier table needed by the IDCT routine. | |
| 20 */ | |
| 21 | |
| 22 #define JPEG_INTERNALS | |
| 23 #include "jinclude.h" | |
| 24 #include "jpeglib.h" | |
| 25 #include "jdct.h" /* Private declarations for DCT subsystem */ | |
| 26 #include "jsimddct.h" | |
| 27 #include "jpegcomp.h" | |
| 28 | |
| 29 | |
| 30 /* | |
| 31 * The decompressor input side (jdinput.c) saves away the appropriate | |
| 32 * quantization table for each component at the start of the first scan | |
| 33 * involving that component. (This is necessary in order to correctly | |
| 34 * decode files that reuse Q-table slots.) | |
| 35 * When we are ready to make an output pass, the saved Q-table is converted | |
| 36 * to a multiplier table that will actually be used by the IDCT routine. | |
| 37 * The multiplier table contents are IDCT-method-dependent. To support | |
| 38 * application changes in IDCT method between scans, we can remake the | |
| 39 * multiplier tables if necessary. | |
| 40 * In buffered-image mode, the first output pass may occur before any data | |
| 41 * has been seen for some components, and thus before their Q-tables have | |
| 42 * been saved away. To handle this case, multiplier tables are preset | |
| 43 * to zeroes; the result of the IDCT will be a neutral gray level. | |
| 44 */ | |
| 45 | |
| 46 | |
| 47 /* Private subobject for this module */ | |
| 48 | |
| 49 typedef struct { | |
| 50 struct jpeg_inverse_dct pub; /* public fields */ | |
| 51 | |
| 52 /* This array contains the IDCT method code that each multiplier table | |
| 53 * is currently set up for, or -1 if it's not yet set up. | |
| 54 * The actual multiplier tables are pointed to by dct_table in the | |
| 55 * per-component comp_info structures. | |
| 56 */ | |
| 57 int cur_method[MAX_COMPONENTS]; | |
| 58 } my_idct_controller; | |
| 59 | |
| 60 typedef my_idct_controller * my_idct_ptr; | |
| 61 | |
| 62 | |
| 63 /* Allocated multiplier tables: big enough for any supported variant */ | |
| 64 | |
| 65 typedef union { | |
| 66 ISLOW_MULT_TYPE islow_array[DCTSIZE2]; | |
| 67 #ifdef DCT_IFAST_SUPPORTED | |
| 68 IFAST_MULT_TYPE ifast_array[DCTSIZE2]; | |
| 69 #endif | |
| 70 #ifdef DCT_FLOAT_SUPPORTED | |
| 71 FLOAT_MULT_TYPE float_array[DCTSIZE2]; | |
| 72 #endif | |
| 73 } multiplier_table; | |
| 74 | |
| 75 | |
| 76 /* The current scaled-IDCT routines require ISLOW-style multiplier tables, | |
| 77 * so be sure to compile that code if either ISLOW or SCALING is requested. | |
| 78 */ | |
| 79 #ifdef DCT_ISLOW_SUPPORTED | |
| 80 #define PROVIDE_ISLOW_TABLES | |
| 81 #else | |
| 82 #ifdef IDCT_SCALING_SUPPORTED | |
| 83 #define PROVIDE_ISLOW_TABLES | |
| 84 #endif | |
| 85 #endif | |
| 86 | |
| 87 | |
| 88 /* | |
| 89 * Prepare for an output pass. | |
| 90 * Here we select the proper IDCT routine for each component and build | |
| 91 * a matching multiplier table. | |
| 92 */ | |
| 93 | |
| 94 METHODDEF(void) | |
| 95 start_pass (j_decompress_ptr cinfo) | |
| 96 { | |
| 97 my_idct_ptr idct = (my_idct_ptr) cinfo->idct; | |
| 98 int ci, i; | |
| 99 jpeg_component_info *compptr; | |
| 100 int method = 0; | |
| 101 inverse_DCT_method_ptr method_ptr = NULL; | |
| 102 JQUANT_TBL * qtbl; | |
| 103 | |
| 104 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 105 ci++, compptr++) { | |
| 106 /* Select the proper IDCT routine for this component's scaling */ | |
| 107 switch (compptr->_DCT_scaled_size) { | |
| 108 #ifdef IDCT_SCALING_SUPPORTED | |
| 109 case 1: | |
| 110 method_ptr = jpeg_idct_1x1; | |
| 111 method = JDCT_ISLOW; /* jidctred uses islow-style table */ | |
| 112 break; | |
| 113 case 2: | |
| 114 if (jsimd_can_idct_2x2()) | |
| 115 method_ptr = jsimd_idct_2x2; | |
| 116 else | |
| 117 method_ptr = jpeg_idct_2x2; | |
| 118 method = JDCT_ISLOW; /* jidctred uses islow-style table */ | |
| 119 break; | |
| 120 case 3: | |
| 121 method_ptr = jpeg_idct_3x3; | |
| 122 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 123 break; | |
| 124 case 4: | |
| 125 if (jsimd_can_idct_4x4()) | |
| 126 method_ptr = jsimd_idct_4x4; | |
| 127 else | |
| 128 method_ptr = jpeg_idct_4x4; | |
| 129 method = JDCT_ISLOW; /* jidctred uses islow-style table */ | |
| 130 break; | |
| 131 case 5: | |
| 132 method_ptr = jpeg_idct_5x5; | |
| 133 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 134 break; | |
| 135 case 6: | |
| 136 method_ptr = jpeg_idct_6x6; | |
| 137 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 138 break; | |
| 139 case 7: | |
| 140 method_ptr = jpeg_idct_7x7; | |
| 141 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 142 break; | |
| 143 #endif | |
| 144 case DCTSIZE: | |
| 145 switch (cinfo->dct_method) { | |
| 146 #ifdef DCT_ISLOW_SUPPORTED | |
| 147 case JDCT_ISLOW: | |
| 148 if (jsimd_can_idct_islow()) | |
| 149 method_ptr = jsimd_idct_islow; | |
| 150 else | |
| 151 method_ptr = jpeg_idct_islow; | |
| 152 method = JDCT_ISLOW; | |
| 153 break; | |
| 154 #endif | |
| 155 #ifdef DCT_IFAST_SUPPORTED | |
| 156 case JDCT_IFAST: | |
| 157 if (jsimd_can_idct_ifast()) | |
| 158 method_ptr = jsimd_idct_ifast; | |
| 159 else | |
| 160 method_ptr = jpeg_idct_ifast; | |
| 161 method = JDCT_IFAST; | |
| 162 break; | |
| 163 #endif | |
| 164 #ifdef DCT_FLOAT_SUPPORTED | |
| 165 case JDCT_FLOAT: | |
| 166 if (jsimd_can_idct_float()) | |
| 167 method_ptr = jsimd_idct_float; | |
| 168 else | |
| 169 method_ptr = jpeg_idct_float; | |
| 170 method = JDCT_FLOAT; | |
| 171 break; | |
| 172 #endif | |
| 173 default: | |
| 174 ERREXIT(cinfo, JERR_NOT_COMPILED); | |
| 175 break; | |
| 176 } | |
| 177 break; | |
| 178 case 9: | |
| 179 method_ptr = jpeg_idct_9x9; | |
| 180 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 181 break; | |
| 182 case 10: | |
| 183 method_ptr = jpeg_idct_10x10; | |
| 184 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 185 break; | |
| 186 case 11: | |
| 187 method_ptr = jpeg_idct_11x11; | |
| 188 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 189 break; | |
| 190 case 12: | |
| 191 method_ptr = jpeg_idct_12x12; | |
| 192 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 193 break; | |
| 194 case 13: | |
| 195 method_ptr = jpeg_idct_13x13; | |
| 196 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 197 break; | |
| 198 case 14: | |
| 199 method_ptr = jpeg_idct_14x14; | |
| 200 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 201 break; | |
| 202 case 15: | |
| 203 method_ptr = jpeg_idct_15x15; | |
| 204 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 205 break; | |
| 206 case 16: | |
| 207 method_ptr = jpeg_idct_16x16; | |
| 208 method = JDCT_ISLOW; /* jidctint uses islow-style table */ | |
| 209 break; | |
| 210 default: | |
| 211 ERREXIT1(cinfo, JERR_BAD_DCTSIZE, compptr->_DCT_scaled_size); | |
| 212 break; | |
| 213 } | |
| 214 idct->pub.inverse_DCT[ci] = method_ptr; | |
| 215 /* Create multiplier table from quant table. | |
| 216 * However, we can skip this if the component is uninteresting | |
| 217 * or if we already built the table. Also, if no quant table | |
| 218 * has yet been saved for the component, we leave the | |
| 219 * multiplier table all-zero; we'll be reading zeroes from the | |
| 220 * coefficient controller's buffer anyway. | |
| 221 */ | |
| 222 if (! compptr->component_needed || idct->cur_method[ci] == method) | |
| 223 continue; | |
| 224 qtbl = compptr->quant_table; | |
| 225 if (qtbl == NULL) /* happens if no data yet for component */ | |
| 226 continue; | |
| 227 idct->cur_method[ci] = method; | |
| 228 switch (method) { | |
| 229 #ifdef PROVIDE_ISLOW_TABLES | |
| 230 case JDCT_ISLOW: | |
| 231 { | |
| 232 /* For LL&M IDCT method, multipliers are equal to raw quantization | |
| 233 * coefficients, but are stored as ints to ensure access efficiency. | |
| 234 */ | |
| 235 ISLOW_MULT_TYPE * ismtbl = (ISLOW_MULT_TYPE *) compptr->dct_table; | |
| 236 for (i = 0; i < DCTSIZE2; i++) { | |
| 237 ismtbl[i] = (ISLOW_MULT_TYPE) qtbl->quantval[i]; | |
| 238 } | |
| 239 } | |
| 240 break; | |
| 241 #endif | |
| 242 #ifdef DCT_IFAST_SUPPORTED | |
| 243 case JDCT_IFAST: | |
| 244 { | |
| 245 /* For AA&N IDCT method, multipliers are equal to quantization | |
| 246 * coefficients scaled by scalefactor[row]*scalefactor[col], where | |
| 247 * scalefactor[0] = 1 | |
| 248 * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7 | |
| 249 * For integer operation, the multiplier table is to be scaled by | |
| 250 * IFAST_SCALE_BITS. | |
| 251 */ | |
| 252 IFAST_MULT_TYPE * ifmtbl = (IFAST_MULT_TYPE *) compptr->dct_table; | |
| 253 #define CONST_BITS 14 | |
| 254 static const INT16 aanscales[DCTSIZE2] = { | |
| 255 /* precomputed values scaled up by 14 bits */ | |
| 256 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520, | |
| 257 22725, 31521, 29692, 26722, 22725, 17855, 12299, 6270, | |
| 258 21407, 29692, 27969, 25172, 21407, 16819, 11585, 5906, | |
| 259 19266, 26722, 25172, 22654, 19266, 15137, 10426, 5315, | |
| 260 16384, 22725, 21407, 19266, 16384, 12873, 8867, 4520, | |
| 261 12873, 17855, 16819, 15137, 12873, 10114, 6967, 3552, | |
| 262 8867, 12299, 11585, 10426, 8867, 6967, 4799, 2446, | |
| 263 4520, 6270, 5906, 5315, 4520, 3552, 2446, 1247 | |
| 264 }; | |
| 265 SHIFT_TEMPS | |
| 266 | |
| 267 for (i = 0; i < DCTSIZE2; i++) { | |
| 268 ifmtbl[i] = (IFAST_MULT_TYPE) | |
| 269 DESCALE(MULTIPLY16V16((INT32) qtbl->quantval[i], | |
| 270 (INT32) aanscales[i]), | |
| 271 CONST_BITS-IFAST_SCALE_BITS); | |
| 272 } | |
| 273 } | |
| 274 break; | |
| 275 #endif | |
| 276 #ifdef DCT_FLOAT_SUPPORTED | |
| 277 case JDCT_FLOAT: | |
| 278 { | |
| 279 /* For float AA&N IDCT method, multipliers are equal to quantization | |
| 280 * coefficients scaled by scalefactor[row]*scalefactor[col], where | |
| 281 * scalefactor[0] = 1 | |
| 282 * scalefactor[k] = cos(k*PI/16) * sqrt(2) for k=1..7 | |
| 283 */ | |
| 284 FLOAT_MULT_TYPE * fmtbl = (FLOAT_MULT_TYPE *) compptr->dct_table; | |
| 285 int row, col; | |
| 286 static const double aanscalefactor[DCTSIZE] = { | |
| 287 1.0, 1.387039845, 1.306562965, 1.175875602, | |
| 288 1.0, 0.785694958, 0.541196100, 0.275899379 | |
| 289 }; | |
| 290 | |
| 291 i = 0; | |
| 292 for (row = 0; row < DCTSIZE; row++) { | |
| 293 for (col = 0; col < DCTSIZE; col++) { | |
| 294 fmtbl[i] = (FLOAT_MULT_TYPE) | |
| 295 ((double) qtbl->quantval[i] * | |
| 296 aanscalefactor[row] * aanscalefactor[col]); | |
| 297 i++; | |
| 298 } | |
| 299 } | |
| 300 } | |
| 301 break; | |
| 302 #endif | |
| 303 default: | |
| 304 ERREXIT(cinfo, JERR_NOT_COMPILED); | |
| 305 break; | |
| 306 } | |
| 307 } | |
| 308 } | |
| 309 | |
| 310 | |
| 311 /* | |
| 312 * Initialize IDCT manager. | |
| 313 */ | |
| 314 | |
| 315 GLOBAL(void) | |
| 316 jinit_inverse_dct (j_decompress_ptr cinfo) | |
| 317 { | |
| 318 my_idct_ptr idct; | |
| 319 int ci; | |
| 320 jpeg_component_info *compptr; | |
| 321 | |
| 322 idct = (my_idct_ptr) | |
| 323 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 324 SIZEOF(my_idct_controller)); | |
| 325 cinfo->idct = (struct jpeg_inverse_dct *) idct; | |
| 326 idct->pub.start_pass = start_pass; | |
| 327 | |
| 328 for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; | |
| 329 ci++, compptr++) { | |
| 330 /* Allocate and pre-zero a multiplier table for each component */ | |
| 331 compptr->dct_table = | |
| 332 (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, | |
| 333 SIZEOF(multiplier_table)); | |
| 334 MEMZERO(compptr->dct_table, SIZEOF(multiplier_table)); | |
| 335 /* Mark multiplier table not yet set up for any method */ | |
| 336 idct->cur_method[ci] = -1; | |
| 337 } | |
| 338 } |
