1 /* 2 * jmorecfg.h 3 * 4 * This file was part of the Independent JPEG Group's software: 5 * Copyright (C) 1991-1997, Thomas G. Lane. 6 * Modified 1997-2009 by Guido Vollbeding. 7 * libjpeg-turbo Modifications: 8 * Copyright (C) 2009, 2011, 2014-2015, 2018, 2020, D. R. Commander. 9 * For conditions of distribution and use, see the accompanying README.ijg 10 * file. 11 * 12 * This file contains additional configuration options that customize the 13 * JPEG software for special applications or support machine-dependent 14 * optimizations. Most users will not need to touch this file. 15 */ 16 17 18 /* 19 * Maximum number of components (color channels) allowed in JPEG image. 20 * To meet the letter of Rec. ITU-T T.81 | ISO/IEC 10918-1, set this to 255. 21 * However, darn few applications need more than 4 channels (maybe 5 for CMYK + 22 * alpha mask). We recommend 10 as a reasonable compromise; use 4 if you are 23 * really short on memory. (Each allowed component costs a hundred or so 24 * bytes of storage, whether actually used in an image or not.) 25 */ 26 27 #define MAX_COMPONENTS 10 /* maximum number of image components */ 28 29 30 /* 31 * Basic data types. 32 * You may need to change these if you have a machine with unusual data 33 * type sizes; for example, "char" not 8 bits, "short" not 16 bits, 34 * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, 35 * but it had better be at least 16. 36 */ 37 38 /* Representation of a single sample (pixel element value). 39 * We frequently allocate large arrays of these, so it's important to keep 40 * them small. But if you have memory to burn and access to char or short 41 * arrays is very slow on your hardware, you might want to change these. 42 */ 43 44 #if BITS_IN_JSAMPLE == 8 45 /* JSAMPLE should be the smallest type that will hold the values 0..255. 46 */ 47 48 typedef unsigned char JSAMPLE; 49 #define GETJSAMPLE(value) ((int)(value)) 50 51 #define MAXJSAMPLE 255 52 #define CENTERJSAMPLE 128 53 54 #endif /* BITS_IN_JSAMPLE == 8 */ 55 56 57 #if BITS_IN_JSAMPLE == 12 58 /* JSAMPLE should be the smallest type that will hold the values 0..4095. 59 * On nearly all machines "short" will do nicely. 60 */ 61 62 typedef short JSAMPLE; 63 #define GETJSAMPLE(value) ((int)(value)) 64 65 #define MAXJSAMPLE 4095 66 #define CENTERJSAMPLE 2048 67 68 #endif /* BITS_IN_JSAMPLE == 12 */ 69 70 71 /* Representation of a DCT frequency coefficient. 72 * This should be a signed value of at least 16 bits; "short" is usually OK. 73 * Again, we allocate large arrays of these, but you can change to int 74 * if you have memory to burn and "short" is really slow. 75 */ 76 77 typedef short JCOEF; 78 79 80 /* Compressed datastreams are represented as arrays of JOCTET. 81 * These must be EXACTLY 8 bits wide, at least once they are written to 82 * external storage. Note that when using the stdio data source/destination 83 * managers, this is also the data type passed to fread/fwrite. 84 */ 85 86 typedef unsigned char JOCTET; 87 #define GETJOCTET(value) (value) 88 89 90 /* These typedefs are used for various table entries and so forth. 91 * They must be at least as wide as specified; but making them too big 92 * won't cost a huge amount of memory, so we don't provide special 93 * extraction code like we did for JSAMPLE. (In other words, these 94 * typedefs live at a different point on the speed/space tradeoff curve.) 95 */ 96 97 /* UINT8 must hold at least the values 0..255. */ 98 99 typedef unsigned char UINT8; 100 101 /* UINT16 must hold at least the values 0..65535. */ 102 103 #ifdef HAVE_UNSIGNED_SHORT 104 typedef unsigned short UINT16; 105 #else /* not HAVE_UNSIGNED_SHORT */ 106 typedef unsigned int UINT16; 107 #endif /* HAVE_UNSIGNED_SHORT */ 108 109 /* INT16 must hold at least the values -32768..32767. */ 110 111 #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ 112 typedef short INT16; 113 #endif 114 115 /* INT32 must hold at least signed 32-bit values. 116 * 117 * NOTE: The INT32 typedef dates back to libjpeg v5 (1994.) Integers were 118 * sometimes 16-bit back then (MS-DOS), which is why INT32 is typedef'd to 119 * long. It also wasn't common (or at least as common) in 1994 for INT32 to be 120 * defined by platform headers. Since then, however, INT32 is defined in 121 * several other common places: 122 * 123 * Xmd.h (X11 header) typedefs INT32 to int on 64-bit platforms and long on 124 * 32-bit platforms (i.e always a 32-bit signed type.) 125 * 126 * basetsd.h (Win32 header) typedefs INT32 to int (always a 32-bit signed type 127 * on modern platforms.) 128 * 129 * qglobal.h (Qt header) typedefs INT32 to int (always a 32-bit signed type on 130 * modern platforms.) 131 * 132 * This is a recipe for conflict, since "long" and "int" aren't always 133 * compatible types. Since the definition of INT32 has technically been part 134 * of the libjpeg API for more than 20 years, we can't remove it, but we do not 135 * use it internally any longer. We instead define a separate type (JLONG) 136 * for internal use, which ensures that internal behavior will always be the 137 * same regardless of any external headers that may be included. 138 */ 139 140 #ifndef XMD_H /* X11/xmd.h correctly defines INT32 */ 141 #ifndef _BASETSD_H_ /* Microsoft defines it in basetsd.h */ 142 #ifndef _BASETSD_H /* MinGW is slightly different */ 143 #ifndef QGLOBAL_H /* Qt defines it in qglobal.h */ 144 typedef long INT32; 145 #endif 146 #endif 147 #endif 148 #endif 149 150 /* Datatype used for image dimensions. The JPEG standard only supports 151 * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore 152 * "unsigned int" is sufficient on all machines. However, if you need to 153 * handle larger images and you don't mind deviating from the spec, you 154 * can change this datatype. (Note that changing this datatype will 155 * potentially require modifying the SIMD code. The x86-64 SIMD extensions, 156 * in particular, assume a 32-bit JDIMENSION.) 157 */ 158 159 typedef unsigned int JDIMENSION; 160 161 #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ 162 163 164 /* These macros are used in all function definitions and extern declarations. 165 * You could modify them if you need to change function linkage conventions; 166 * in particular, you'll need to do that to make the library a Windows DLL. 167 * Another application is to make all functions global for use with debuggers 168 * or code profilers that require it. 169 */ 170 171 /* a function called through method pointers: */ 172 #define METHODDEF(type) static type 173 /* a function used only in its module: */ 174 #define LOCAL(type) static type 175 /* a function referenced thru EXTERNs: */ 176 #define GLOBAL(type) type 177 /* a reference to a GLOBAL function: */ 178 #define EXTERN(type) extern type 179 180 181 /* Originally, this macro was used as a way of defining function prototypes 182 * for both modern compilers as well as older compilers that did not support 183 * prototype parameters. libjpeg-turbo has never supported these older, 184 * non-ANSI compilers, but the macro is still included because there is some 185 * software out there that uses it. 186 */ 187 188 #define JMETHOD(type, methodname, arglist) type (*methodname) arglist 189 190 191 /* libjpeg-turbo no longer supports platforms that have far symbols (MS-DOS), 192 * but again, some software relies on this macro. 193 */ 194 195 #undef FAR 196 #define FAR 197 198 199 /* 200 * On a few systems, type boolean and/or its values FALSE, TRUE may appear 201 * in standard header files. Or you may have conflicts with application- 202 * specific header files that you want to include together with these files. 203 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. 204 */ 205 206 #ifndef HAVE_BOOLEAN 207 typedef int boolean; 208 #endif 209 #ifndef FALSE /* in case these macros already exist */ 210 #define FALSE 0 /* values of boolean */ 211 #endif 212 #ifndef TRUE 213 #define TRUE 1 214 #endif 215 216 217 /* 218 * The remaining options affect code selection within the JPEG library, 219 * but they don't need to be visible to most applications using the library. 220 * To minimize application namespace pollution, the symbols won't be 221 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. 222 */ 223 224 #ifdef JPEG_INTERNALS 225 #define JPEG_INTERNAL_OPTIONS 226 #endif 227 228 #ifdef JPEG_INTERNAL_OPTIONS 229 230 231 /* 232 * These defines indicate whether to include various optional functions. 233 * Undefining some of these symbols will produce a smaller but less capable 234 * library. Note that you can leave certain source files out of the 235 * compilation/linking process if you've #undef'd the corresponding symbols. 236 * (You may HAVE to do that if your compiler doesn't like null source files.) 237 */ 238 239 /* Capability options common to encoder and decoder: */ 240 241 #define DCT_ISLOW_SUPPORTED /* accurate integer method */ 242 #define DCT_IFAST_SUPPORTED /* less accurate int method [legacy feature] */ 243 #define DCT_FLOAT_SUPPORTED /* floating-point method [legacy feature] */ 244 245 /* Encoder capability options: */ 246 247 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 248 #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 249 #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ 250 /* Note: if you selected 12-bit data precision, it is dangerous to turn off 251 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit 252 * precision, so jchuff.c normally uses entropy optimization to compute 253 * usable tables for higher precision. If you don't want to do optimization, 254 * you'll have to supply different default Huffman tables. 255 * The exact same statements apply for progressive JPEG: the default tables 256 * don't work for progressive mode. (This may get fixed, however.) 257 */ 258 #define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ 259 260 /* Decoder capability options: */ 261 262 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 263 #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 264 #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ 265 #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ 266 #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ 267 #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ 268 #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ 269 #define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ 270 #define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ 271 272 /* more capability options later, no doubt */ 273 274 275 /* 276 * The RGB_RED, RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros are a vestigial 277 * feature of libjpeg. The idea was that, if an application developer needed 278 * to compress from/decompress to a BGR/BGRX/RGBX/XBGR/XRGB buffer, they could 279 * change these macros, rebuild libjpeg, and link their application statically 280 * with it. In reality, few people ever did this, because there were some 281 * severe restrictions involved (cjpeg and djpeg no longer worked properly, 282 * compressing/decompressing RGB JPEGs no longer worked properly, and the color 283 * quantizer wouldn't work with pixel sizes other than 3.) Furthermore, since 284 * all of the O/S-supplied versions of libjpeg were built with the default 285 * values of RGB_RED, RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE, many applications 286 * have come to regard these values as immutable. 287 * 288 * The libjpeg-turbo colorspace extensions provide a much cleaner way of 289 * compressing from/decompressing to buffers with arbitrary component orders 290 * and pixel sizes. Thus, we do not support changing the values of RGB_RED, 291 * RGB_GREEN, RGB_BLUE, or RGB_PIXELSIZE. In addition to the restrictions 292 * listed above, changing these values will also break the SIMD extensions and 293 * the regression tests. 294 */ 295 296 #define RGB_RED 0 /* Offset of Red in an RGB scanline element */ 297 #define RGB_GREEN 1 /* Offset of Green */ 298 #define RGB_BLUE 2 /* Offset of Blue */ 299 #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ 300 301 #define JPEG_NUMCS 17 302 303 #define EXT_RGB_RED 0 304 #define EXT_RGB_GREEN 1 305 #define EXT_RGB_BLUE 2 306 #define EXT_RGB_PIXELSIZE 3 307 308 #define EXT_RGBX_RED 0 309 #define EXT_RGBX_GREEN 1 310 #define EXT_RGBX_BLUE 2 311 #define EXT_RGBX_PIXELSIZE 4 312 313 #define EXT_BGR_RED 2 314 #define EXT_BGR_GREEN 1 315 #define EXT_BGR_BLUE 0 316 #define EXT_BGR_PIXELSIZE 3 317 318 #define EXT_BGRX_RED 2 319 #define EXT_BGRX_GREEN 1 320 #define EXT_BGRX_BLUE 0 321 #define EXT_BGRX_PIXELSIZE 4 322 323 #define EXT_XBGR_RED 3 324 #define EXT_XBGR_GREEN 2 325 #define EXT_XBGR_BLUE 1 326 #define EXT_XBGR_PIXELSIZE 4 327 328 #define EXT_XRGB_RED 1 329 #define EXT_XRGB_GREEN 2 330 #define EXT_XRGB_BLUE 3 331 #define EXT_XRGB_PIXELSIZE 4 332 333 static const int rgb_red[JPEG_NUMCS] = { 334 -1, -1, RGB_RED, -1, -1, -1, EXT_RGB_RED, EXT_RGBX_RED, 335 EXT_BGR_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED, 336 EXT_RGBX_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED, 337 -1 338 }; 339 340 static const int rgb_green[JPEG_NUMCS] = { 341 -1, -1, RGB_GREEN, -1, -1, -1, EXT_RGB_GREEN, EXT_RGBX_GREEN, 342 EXT_BGR_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN, 343 EXT_RGBX_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN, 344 -1 345 }; 346 347 static const int rgb_blue[JPEG_NUMCS] = { 348 -1, -1, RGB_BLUE, -1, -1, -1, EXT_RGB_BLUE, EXT_RGBX_BLUE, 349 EXT_BGR_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE, 350 EXT_RGBX_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE, 351 -1 352 }; 353 354 static const int rgb_pixelsize[JPEG_NUMCS] = { 355 -1, -1, RGB_PIXELSIZE, -1, -1, -1, EXT_RGB_PIXELSIZE, EXT_RGBX_PIXELSIZE, 356 EXT_BGR_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE, 357 EXT_RGBX_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE, 358 -1 359 }; 360 361 /* Definitions for speed-related optimizations. */ 362 363 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying 364 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER 365 * as short on such a machine. MULTIPLIER must be at least 16 bits wide. 366 */ 367 368 #ifndef MULTIPLIER 369 #ifndef WITH_SIMD 370 #define MULTIPLIER int /* type for fastest integer multiply */ 371 #else 372 #define MULTIPLIER short /* prefer 16-bit with SIMD for parellelism */ 373 #endif 374 #endif 375 376 377 /* FAST_FLOAT should be either float or double, whichever is done faster 378 * by your compiler. (Note that this type is only used in the floating point 379 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) 380 */ 381 382 #ifndef FAST_FLOAT 383 #define FAST_FLOAT float 384 #endif 385 386 #endif /* JPEG_INTERNAL_OPTIONS */ 387