1/* 2 * reserved comment block 3 * DO NOT REMOVE OR ALTER! 4 */ 5/* 6 * jmorecfg.h 7 * 8 * Copyright (C) 1991-1997, Thomas G. Lane. 9 * This file is part of the Independent JPEG Group's software. 10 * For conditions of distribution and use, see the accompanying README 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 * Define BITS_IN_JSAMPLE as either 20 * 8 for 8-bit sample values (the usual setting) 21 * 12 for 12-bit sample values 22 * Only 8 and 12 are legal data precisions for lossy JPEG according to the 23 * JPEG standard, and the IJG code does not support anything else! 24 * We do not support run-time selection of data precision, sorry. 25 */ 26 27#define BITS_IN_JSAMPLE 8 /* use 8 or 12 */ 28 29 30/* 31 * Maximum number of components (color channels) allowed in JPEG image. 32 * To meet the letter of the JPEG spec, set this to 255. However, darn 33 * few applications need more than 4 channels (maybe 5 for CMYK + alpha 34 * mask). We recommend 10 as a reasonable compromise; use 4 if you are 35 * really short on memory. (Each allowed component costs a hundred or so 36 * bytes of storage, whether actually used in an image or not.) 37 */ 38 39#define MAX_COMPONENTS 10 /* maximum number of image components */ 40 41 42/* 43 * Basic data types. 44 * You may need to change these if you have a machine with unusual data 45 * type sizes; for example, "char" not 8 bits, "short" not 16 bits, 46 * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, 47 * but it had better be at least 16. 48 */ 49 50/* Representation of a single sample (pixel element value). 51 * We frequently allocate large arrays of these, so it's important to keep 52 * them small. But if you have memory to burn and access to char or short 53 * arrays is very slow on your hardware, you might want to change these. 54 */ 55 56#if BITS_IN_JSAMPLE == 8 57/* JSAMPLE should be the smallest type that will hold the values 0..255. 58 * You can use a signed char by having GETJSAMPLE mask it with 0xFF. 59 */ 60 61#ifdef HAVE_UNSIGNED_CHAR 62 63typedef unsigned char JSAMPLE; 64#define GETJSAMPLE(value) ((int) (value)) 65 66#else /* not HAVE_UNSIGNED_CHAR */ 67 68typedef char JSAMPLE; 69#ifdef CHAR_IS_UNSIGNED 70#define GETJSAMPLE(value) ((int) (value)) 71#else 72#define GETJSAMPLE(value) ((int) (value) & 0xFF) 73#endif /* CHAR_IS_UNSIGNED */ 74 75#endif /* HAVE_UNSIGNED_CHAR */ 76 77#define MAXJSAMPLE 255 78#define CENTERJSAMPLE 128 79 80#endif /* BITS_IN_JSAMPLE == 8 */ 81 82 83#if BITS_IN_JSAMPLE == 12 84/* JSAMPLE should be the smallest type that will hold the values 0..4095. 85 * On nearly all machines "short" will do nicely. 86 */ 87 88typedef short JSAMPLE; 89#define GETJSAMPLE(value) ((int) (value)) 90 91#define MAXJSAMPLE 4095 92#define CENTERJSAMPLE 2048 93 94#endif /* BITS_IN_JSAMPLE == 12 */ 95 96 97/* Representation of a DCT frequency coefficient. 98 * This should be a signed value of at least 16 bits; "short" is usually OK. 99 * Again, we allocate large arrays of these, but you can change to int 100 * if you have memory to burn and "short" is really slow. 101 */ 102 103typedef short JCOEF; 104 105 106/* Compressed datastreams are represented as arrays of JOCTET. 107 * These must be EXACTLY 8 bits wide, at least once they are written to 108 * external storage. Note that when using the stdio data source/destination 109 * managers, this is also the data type passed to fread/fwrite. 110 */ 111 112#ifdef HAVE_UNSIGNED_CHAR 113 114typedef unsigned char JOCTET; 115#define GETJOCTET(value) (value) 116 117#else /* not HAVE_UNSIGNED_CHAR */ 118 119typedef char JOCTET; 120#ifdef CHAR_IS_UNSIGNED 121#define GETJOCTET(value) (value) 122#else 123#define GETJOCTET(value) ((value) & 0xFF) 124#endif /* CHAR_IS_UNSIGNED */ 125 126#endif /* HAVE_UNSIGNED_CHAR */ 127 128 129/* These typedefs are used for various table entries and so forth. 130 * They must be at least as wide as specified; but making them too big 131 * won't cost a huge amount of memory, so we don't provide special 132 * extraction code like we did for JSAMPLE. (In other words, these 133 * typedefs live at a different point on the speed/space tradeoff curve.) 134 */ 135 136/* UINT8 must hold at least the values 0..255. */ 137 138#ifdef HAVE_UNSIGNED_CHAR 139typedef unsigned char UINT8; 140#else /* not HAVE_UNSIGNED_CHAR */ 141#ifdef CHAR_IS_UNSIGNED 142typedef char UINT8; 143#else /* not CHAR_IS_UNSIGNED */ 144typedef short UINT8; 145#endif /* CHAR_IS_UNSIGNED */ 146#endif /* HAVE_UNSIGNED_CHAR */ 147 148/* UINT16 must hold at least the values 0..65535. */ 149 150#ifdef HAVE_UNSIGNED_SHORT 151typedef unsigned short UINT16; 152#else /* not HAVE_UNSIGNED_SHORT */ 153typedef unsigned int UINT16; 154#endif /* HAVE_UNSIGNED_SHORT */ 155 156/* INT16 must hold at least the values -32768..32767. */ 157 158#ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ 159typedef short INT16; 160#endif 161 162/* INT32 must hold at least signed 32-bit values. */ 163 164#ifndef XMD_H /* X11/xmd.h correctly defines INT32 */ 165#if defined(_LP64) || defined(_WIN32) /* _WIN32 is on all windows platfroms (x86 and x64) */ 166typedef int INT32; 167#else 168typedef long INT32; 169#endif 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 179typedef unsigned int JDIMENSION; 180 181#ifndef _LP64 182#define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ 183#else 184#define JPEG_MAX_DIMENSION 65500 /* a tad under 64K to prevent overflows */ 185#endif 186 187 188/* These macros are used in all function definitions and extern declarations. 189 * You could modify them if you need to change function linkage conventions; 190 * in particular, you'll need to do that to make the library a Windows DLL. 191 * Another application is to make all functions global for use with debuggers 192 * or code profilers that require it. 193 */ 194 195/* a function called through method pointers: */ 196#define METHODDEF(type) static type 197/* a function used only in its module: */ 198#define LOCAL(type) static type 199/* a function referenced thru EXTERNs: */ 200#define GLOBAL(type) type 201/* a reference to a GLOBAL function: */ 202#define EXTERN(type) extern type 203 204 205/* This macro is used to declare a "method", that is, a function pointer. 206 * We want to supply prototype parameters if the compiler can cope. 207 * Note that the arglist parameter must be parenthesized! 208 * Again, you can customize this if you need special linkage keywords. 209 */ 210 211#ifdef HAVE_PROTOTYPES 212#define JMETHOD(type,methodname,arglist) type (*methodname) arglist 213#else 214#define JMETHOD(type,methodname,arglist) type (*methodname) () 215#endif 216 217 218/* Here is the pseudo-keyword for declaring pointers that must be "far" 219 * on 80x86 machines. Most of the specialized coding for 80x86 is handled 220 * by just saying "FAR *" where such a pointer is needed. In a few places 221 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. 222 */ 223 224 225#ifndef FAR 226#ifdef NEED_FAR_POINTERS 227#define FAR far 228#else 229#define FAR 230#endif 231#endif 232 233 234/* 235 * On a few systems, type boolean and/or its values FALSE, TRUE may appear 236 * in standard header files. Or you may have conflicts with application- 237 * specific header files that you want to include together with these files. 238 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. 239 */ 240 241#ifndef HAVE_BOOLEAN 242typedef int boolean; 243#endif 244#ifndef FALSE /* in case these macros already exist */ 245#define FALSE 0 /* values of boolean */ 246#endif 247#ifndef TRUE 248#define TRUE 1 249#endif 250 251 252/* 253 * The remaining options affect code selection within the JPEG library, 254 * but they don't need to be visible to most applications using the library. 255 * To minimize application namespace pollution, the symbols won't be 256 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. 257 */ 258 259#ifdef JPEG_INTERNALS 260#define JPEG_INTERNAL_OPTIONS 261#endif 262 263#ifdef JPEG_INTERNAL_OPTIONS 264 265 266/* 267 * These defines indicate whether to include various optional functions. 268 * Undefining some of these symbols will produce a smaller but less capable 269 * library. Note that you can leave certain source files out of the 270 * compilation/linking process if you've #undef'd the corresponding symbols. 271 * (You may HAVE to do that if your compiler doesn't like null source files.) 272 */ 273 274/* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */ 275 276/* Capability options common to encoder and decoder: */ 277 278#define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ 279#define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ 280#define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ 281 282/* Encoder capability options: */ 283 284#undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 285#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 286#define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 287#define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ 288/* Note: if you selected 12-bit data precision, it is dangerous to turn off 289 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit 290 * precision, so jchuff.c normally uses entropy optimization to compute 291 * usable tables for higher precision. If you don't want to do optimization, 292 * you'll have to supply different default Huffman tables. 293 * The exact same statements apply for progressive JPEG: the default tables 294 * don't work for progressive mode. (This may get fixed, however.) 295 */ 296#define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ 297 298/* Decoder capability options: */ 299 300#undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 301#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 302#define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 303#define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ 304#define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ 305#define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ 306#undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ 307#define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ 308#define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ 309#define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ 310 311/* more capability options later, no doubt */ 312 313 314/* 315 * Ordering of RGB data in scanlines passed to or from the application. 316 * If your application wants to deal with data in the order B,G,R, just 317 * change these macros. You can also deal with formats such as R,G,B,X 318 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing 319 * the offsets will also change the order in which colormap data is organized. 320 * RESTRICTIONS: 321 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. 322 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not 323 * useful if you are using JPEG color spaces other than YCbCr or grayscale. 324 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE 325 * is not 3 (they don't understand about dummy color components!). So you 326 * can't use color quantization if you change that value. 327 */ 328 329#define RGB_RED 0 /* Offset of Red in an RGB scanline element */ 330#define RGB_GREEN 1 /* Offset of Green */ 331#define RGB_BLUE 2 /* Offset of Blue */ 332#define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ 333 334 335/* Definitions for speed-related optimizations. */ 336 337 338/* If your compiler supports inline functions, define INLINE 339 * as the inline keyword; otherwise define it as empty. 340 */ 341 342#ifndef INLINE 343#ifdef __GNUC__ /* for instance, GNU C knows about inline */ 344#define INLINE __inline__ 345#endif 346#ifndef INLINE 347#define INLINE /* default is to define it as empty */ 348#endif 349#endif 350 351 352/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying 353 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER 354 * as short on such a machine. MULTIPLIER must be at least 16 bits wide. 355 */ 356 357#ifndef MULTIPLIER 358#define MULTIPLIER int /* type for fastest integer multiply */ 359#endif 360 361 362/* FAST_FLOAT should be either float or double, whichever is done faster 363 * by your compiler. (Note that this type is only used in the floating point 364 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) 365 * Typically, float is faster in ANSI C compilers, while double is faster in 366 * pre-ANSI compilers (because they insist on converting to double anyway). 367 * The code below therefore chooses float if we have ANSI-style prototypes. 368 */ 369 370#ifndef FAST_FLOAT 371#ifdef HAVE_PROTOTYPES 372#define FAST_FLOAT float 373#else 374#define FAST_FLOAT double 375#endif 376#endif 377 378#endif /* JPEG_INTERNAL_OPTIONS */ 379