1 /* 2 * jmorecfg.h 3 * 4 * Copyright (C) 1991-1997, Thomas G. Lane. 5 * This file is part of the Independent JPEG Group's software. 6 * For conditions of distribution and use, see the accompanying README file. 7 * 8 * This file contains additional configuration options that customize the 9 * JPEG software for special applications or support machine-dependent 10 * optimizations. Most users will not need to touch this file. 11 */ 12 13 #ifdef _MSC_VER 14 #pragma warning (disable : 4142) 15 #endif 16 17 /* 18 * Define BITS_IN_JSAMPLE as either 19 * 8 for 8-bit sample values (the usual setting) 20 * 12 for 12-bit sample values 21 * Only 8 and 12 are legal data precisions for lossy JPEG according to the 22 * JPEG standard, and the IJG code does not support anything else! 23 * We do not support run-time selection of data precision, sorry. 24 */ 25 26 #define BITS_IN_JSAMPLE 8 /* use 8 or 12 */ 27 28 29 /* 30 * Maximum number of components (color channels) allowed in JPEG image. 31 * To meet the letter of the JPEG spec, set this to 255. However, darn 32 * few applications need more than 4 channels (maybe 5 for CMYK + alpha 33 * mask). We recommend 10 as a reasonable compromise; use 4 if you are 34 * really short on memory. (Each allowed component costs a hundred or so 35 * bytes of storage, whether actually used in an image or not.) 36 */ 37 38 #define MAX_COMPONENTS 10 /* maximum number of image components */ 39 40 41 /* 42 * Basic data types. 43 * You may need to change these if you have a machine with unusual data 44 * type sizes; for example, "char" not 8 bits, "short" not 16 bits, 45 * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, 46 * but it had better be at least 16. 47 */ 48 49 /* Representation of a single sample (pixel element value). 50 * We frequently allocate large arrays of these, so it's important to keep 51 * them small. But if you have memory to burn and access to char or short 52 * arrays is very slow on your hardware, you might want to change these. 53 */ 54 55 #if BITS_IN_JSAMPLE == 8 56 /* JSAMPLE should be the smallest type that will hold the values 0..255. 57 * You can use a signed char by having GETJSAMPLE mask it with 0xFF. 58 */ 59 60 #ifdef HAVE_UNSIGNED_CHAR 61 62 typedef unsigned char JSAMPLE; 63 #define GETJSAMPLE(value) ((int) (value)) 64 65 #else /* not HAVE_UNSIGNED_CHAR */ 66 67 typedef char JSAMPLE; 68 #ifdef CHAR_IS_UNSIGNED 69 #define GETJSAMPLE(value) ((int) (value)) 70 #else 71 #define GETJSAMPLE(value) ((int) (value) & 0xFF) 72 #endif /* CHAR_IS_UNSIGNED */ 73 74 #endif /* HAVE_UNSIGNED_CHAR */ 75 76 #define MAXJSAMPLE 255 77 #define CENTERJSAMPLE 128 78 79 #endif /* BITS_IN_JSAMPLE == 8 */ 80 81 82 #if BITS_IN_JSAMPLE == 12 83 /* JSAMPLE should be the smallest type that will hold the values 0..4095. 84 * On nearly all machines "short" will do nicely. 85 */ 86 87 typedef short JSAMPLE; 88 #define GETJSAMPLE(value) ((int) (value)) 89 90 #define MAXJSAMPLE 4095 91 #define CENTERJSAMPLE 2048 92 93 #endif /* BITS_IN_JSAMPLE == 12 */ 94 95 96 /* Representation of a DCT frequency coefficient. 97 * This should be a signed value of at least 16 bits; "short" is usually OK. 98 * Again, we allocate large arrays of these, but you can change to int 99 * if you have memory to burn and "short" is really slow. 100 */ 101 102 typedef short JCOEF; 103 104 105 /* Compressed datastreams are represented as arrays of JOCTET. 106 * These must be EXACTLY 8 bits wide, at least once they are written to 107 * external storage. Note that when using the stdio data source/destination 108 * managers, this is also the data type passed to fread/fwrite. 109 */ 110 111 #ifdef HAVE_UNSIGNED_CHAR 112 113 typedef unsigned char JOCTET; 114 #define GETJOCTET(value) (value) 115 116 #else /* not HAVE_UNSIGNED_CHAR */ 117 118 typedef char JOCTET; 119 #ifdef CHAR_IS_UNSIGNED 120 #define GETJOCTET(value) (value) 121 #else 122 #define GETJOCTET(value) ((value) & 0xFF) 123 #endif /* CHAR_IS_UNSIGNED */ 124 125 #endif /* HAVE_UNSIGNED_CHAR */ 126 127 128 /* These typedefs are used for various table entries and so forth. 129 * They must be at least as wide as specified; but making them too big 130 * won't cost a huge amount of memory, so we don't provide special 131 * extraction code like we did for JSAMPLE. (In other words, these 132 * typedefs live at a different point on the speed/space tradeoff curve.) 133 */ 134 135 #if _FX_OS_ != _FX_VXWORKS_ 136 137 /* UINT8 must hold at least the values 0..255. */ 138 139 #ifdef HAVE_UNSIGNED_CHAR 140 typedef unsigned char UINT8; 141 #else /* not HAVE_UNSIGNED_CHAR */ 142 #ifdef CHAR_IS_UNSIGNED 143 typedef char UINT8; 144 #else /* not CHAR_IS_UNSIGNED */ 145 typedef short UINT8; 146 #endif /* CHAR_IS_UNSIGNED */ 147 #endif /* HAVE_UNSIGNED_CHAR */ 148 149 150 /* UINT16 must hold at least the values 0..65535. */ 151 152 #ifdef HAVE_UNSIGNED_SHORT 153 typedef unsigned short UINT16; 154 #else /* not HAVE_UNSIGNED_SHORT */ 155 typedef unsigned int UINT16; 156 #endif /* HAVE_UNSIGNED_SHORT */ 157 158 /* INT16 must hold at least the values -32768..32767. */ 159 160 #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ 161 typedef short INT16; 162 #endif 163 164 /* INT32 must hold at least signed 32-bit values. */ 165 166 #ifndef XMD_H /* X11/xmd.h correctly defines INT32 */ 167 typedef int INT32; 168 #endif 169 170 #endif 171 172 /* Datatype used for image dimensions. The JPEG standard only supports 173 * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore 174 * "unsigned int" is sufficient on all machines. However, if you need to 175 * handle larger images and you don't mind deviating from the spec, you 176 * can change this datatype. 177 */ 178 179 typedef unsigned int JDIMENSION; 180 181 #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ 182 183 184 /* These macros are used in all function definitions and extern declarations. 185 * You could modify them if you need to change function linkage conventions; 186 * in particular, you'll need to do that to make the library a Windows DLL. 187 * Another application is to make all functions global for use with debuggers 188 * or code profilers that require it. 189 */ 190 191 /* a function called through method pointers: */ 192 #define METHODDEF(type) static type 193 /* a function used only in its module: */ 194 #define LOCAL(type) static type 195 /* a function referenced thru EXTERNs: */ 196 #define GLOBAL(type) type 197 198 #ifdef _FX_MANAGED_CODE_ 199 #define EXTERN(type) extern "C" type 200 #else 201 /* a reference to a GLOBAL function: */ 202 #define EXTERN(type) extern type 203 #endif 204 205 206 /* This macro is used to declare a "method", that is, a function pointer. 207 * We want to supply prototype parameters if the compiler can cope. 208 * Note that the arglist parameter must be parenthesized! 209 * Again, you can customize this if you need special linkage keywords. 210 */ 211 212 #ifdef HAVE_PROTOTYPES 213 #define JMETHOD(type,methodname,arglist) type (*methodname) arglist 214 #else 215 #define JMETHOD(type,methodname,arglist) type (*methodname) () 216 #endif 217 218 219 /* Here is the pseudo-keyword for declaring pointers that must be "far" 220 * on 80x86 machines. Most of the specialized coding for 80x86 is handled 221 * by just saying "FAR *" where such a pointer is needed. In a few places 222 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. 223 */ 224 225 #ifdef NEED_FAR_POINTERS 226 #define FAR far 227 #else 228 //#define FAR 229 #endif 230 231 232 /* 233 * On a few systems, type boolean and/or its values FALSE, TRUE may appear 234 * in standard header files. Or you may have conflicts with application- 235 * specific header files that you want to include together with these files. 236 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. 237 */ 238 239 #ifndef HAVE_BOOLEAN 240 typedef int boolean; 241 #endif 242 #ifndef FALSE /* in case these macros already exist */ 243 #define FALSE 0 /* values of boolean */ 244 #endif 245 #ifndef TRUE 246 #define TRUE 1 247 #endif 248 249 250 /* 251 * The remaining options affect code selection within the JPEG library, 252 * but they don't need to be visible to most applications using the library. 253 * To minimize application namespace pollution, the symbols won't be 254 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. 255 */ 256 257 #ifdef JPEG_INTERNALS 258 #define JPEG_INTERNAL_OPTIONS 259 #endif 260 261 #ifdef JPEG_INTERNAL_OPTIONS 262 263 264 /* 265 * These defines indicate whether to include various optional functions. 266 * Undefining some of these symbols will produce a smaller but less capable 267 * library. Note that you can leave certain source files out of the 268 * compilation/linking process if you've #undef'd the corresponding symbols. 269 * (You may HAVE to do that if your compiler doesn't like null source files.) 270 */ 271 272 /* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */ 273 274 /* Capability options common to encoder and decoder: */ 275 276 #define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ 277 #define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ 278 #undef DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ 279 280 /* Encoder capability options: */ 281 282 #undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 283 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 284 #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 285 #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ 286 /* Note: if you selected 12-bit data precision, it is dangerous to turn off 287 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit 288 * precision, so jchuff.c normally uses entropy optimization to compute 289 * usable tables for higher precision. If you don't want to do optimization, 290 * you'll have to supply different default Huffman tables. 291 * The exact same statements apply for progressive JPEG: the default tables 292 * don't work for progressive mode. (This may get fixed, however.) 293 */ 294 #define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ 295 296 /* Decoder capability options: */ 297 298 #undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 299 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 300 #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 301 #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ 302 #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ 303 #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ 304 #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ 305 #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ 306 #undef QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ 307 #undef QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ 308 309 /* more capability options later, no doubt */ 310 311 312 /* 313 * Ordering of RGB data in scanlines passed to or from the application. 314 * If your application wants to deal with data in the order B,G,R, just 315 * change these macros. You can also deal with formats such as R,G,B,X 316 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing 317 * the offsets will also change the order in which colormap data is organized. 318 * RESTRICTIONS: 319 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. 320 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not 321 * useful if you are using JPEG color spaces other than YCbCr or grayscale. 322 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE 323 * is not 3 (they don't understand about dummy color components!). So you 324 * can't use color quantization if you change that value. 325 */ 326 327 #define RGB_RED 0 /* Offset of Red in an RGB scanline element */ 328 #define RGB_GREEN 1 /* Offset of Green */ 329 #define RGB_BLUE 2 /* Offset of Blue */ 330 #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ 331 332 333 /* Definitions for speed-related optimizations. */ 334 335 336 /* If your compiler supports inline functions, define INLINE 337 * as the inline keyword; otherwise define it as empty. 338 */ 339 340 #ifndef INLINE 341 #ifdef __GNUC__ /* for instance, GNU C knows about inline */ 342 #define INLINE __inline__ 343 #endif 344 #ifndef INLINE 345 #define INLINE /* default is to define it as empty */ 346 #endif 347 #endif 348 349 350 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying 351 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER 352 * as short on such a machine. MULTIPLIER must be at least 16 bits wide. 353 */ 354 355 #ifndef MULTIPLIER 356 #define MULTIPLIER int /* type for fastest integer multiply */ 357 #endif 358 359 360 /* FAST_FLOAT should be either float or double, whichever is done faster 361 * by your compiler. (Note that this type is only used in the floating point 362 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) 363 * Typically, float is faster in ANSI C compilers, while double is faster in 364 * pre-ANSI compilers (because they insist on converting to double anyway). 365 * The code below therefore chooses float if we have ANSI-style prototypes. 366 */ 367 368 #ifndef FAST_FLOAT 369 #ifdef HAVE_PROTOTYPES 370 #define FAST_FLOAT float 371 #else 372 #define FAST_FLOAT double 373 #endif 374 #endif 375 376 #endif /* JPEG_INTERNAL_OPTIONS */ 377