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 62typedef unsigned char JSAMPLE; 63#define GETJSAMPLE(value) ((int) (value)) 64 65#else /* not HAVE_UNSIGNED_CHAR */ 66 67typedef 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 87typedef 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 102typedef 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 113typedef unsigned char JOCTET; 114#define GETJOCTET(value) (value) 115 116#else /* not HAVE_UNSIGNED_CHAR */ 117 118typedef 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 140typedef unsigned char UINT8; 141#else /* not HAVE_UNSIGNED_CHAR */ 142#ifdef CHAR_IS_UNSIGNED 143typedef char UINT8; 144#else /* not CHAR_IS_UNSIGNED */ 145typedef 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 153typedef unsigned short UINT16; 154#else /* not HAVE_UNSIGNED_SHORT */ 155typedef 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 */ 161typedef 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 */ 167typedef 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 179typedef 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/* a reference to a GLOBAL function: */ 199#define EXTERN(type) extern type 200 201 202/* This macro is used to declare a "method", that is, a function pointer. 203 * We want to supply prototype parameters if the compiler can cope. 204 * Note that the arglist parameter must be parenthesized! 205 * Again, you can customize this if you need special linkage keywords. 206 */ 207 208#ifdef HAVE_PROTOTYPES 209#define JMETHOD(type,methodname,arglist) type (*methodname) arglist 210#else 211#define JMETHOD(type,methodname,arglist) type (*methodname) () 212#endif 213 214 215/* Here is the pseudo-keyword for declaring pointers that must be "far" 216 * on 80x86 machines. Most of the specialized coding for 80x86 is handled 217 * by just saying "FAR *" where such a pointer is needed. In a few places 218 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. 219 */ 220 221#ifdef NEED_FAR_POINTERS 222#define FAR far 223#else 224//#define FAR 225#endif 226 227 228/* 229 * On a few systems, type boolean and/or its values FALSE, TRUE may appear 230 * in standard header files. Or you may have conflicts with application- 231 * specific header files that you want to include together with these files. 232 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. 233 */ 234 235#ifndef HAVE_BOOLEAN 236typedef int boolean; 237#endif 238#ifndef FALSE /* in case these macros already exist */ 239#define FALSE 0 /* values of boolean */ 240#endif 241#ifndef TRUE 242#define TRUE 1 243#endif 244 245 246/* 247 * The remaining options affect code selection within the JPEG library, 248 * but they don't need to be visible to most applications using the library. 249 * To minimize application namespace pollution, the symbols won't be 250 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. 251 */ 252 253#ifdef JPEG_INTERNALS 254#define JPEG_INTERNAL_OPTIONS 255#endif 256 257#ifdef JPEG_INTERNAL_OPTIONS 258 259 260/* 261 * These defines indicate whether to include various optional functions. 262 * Undefining some of these symbols will produce a smaller but less capable 263 * library. Note that you can leave certain source files out of the 264 * compilation/linking process if you've #undef'd the corresponding symbols. 265 * (You may HAVE to do that if your compiler doesn't like null source files.) 266 */ 267 268/* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */ 269 270/* Capability options common to encoder and decoder: */ 271 272#define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ 273#define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ 274#undef DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ 275 276/* Encoder capability options: */ 277 278#undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 279#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 280#define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 281#define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ 282/* Note: if you selected 12-bit data precision, it is dangerous to turn off 283 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit 284 * precision, so jchuff.c normally uses entropy optimization to compute 285 * usable tables for higher precision. If you don't want to do optimization, 286 * you'll have to supply different default Huffman tables. 287 * The exact same statements apply for progressive JPEG: the default tables 288 * don't work for progressive mode. (This may get fixed, however.) 289 */ 290#define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ 291 292/* Decoder capability options: */ 293 294#undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 295#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 296#define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 297#define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ 298#define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ 299#define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ 300#undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ 301#define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ 302#undef QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ 303#undef QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ 304 305/* more capability options later, no doubt */ 306 307 308/* 309 * Ordering of RGB data in scanlines passed to or from the application. 310 * If your application wants to deal with data in the order B,G,R, just 311 * change these macros. You can also deal with formats such as R,G,B,X 312 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing 313 * the offsets will also change the order in which colormap data is organized. 314 * RESTRICTIONS: 315 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. 316 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not 317 * useful if you are using JPEG color spaces other than YCbCr or grayscale. 318 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE 319 * is not 3 (they don't understand about dummy color components!). So you 320 * can't use color quantization if you change that value. 321 */ 322 323#define RGB_RED 0 /* Offset of Red in an RGB scanline element */ 324#define RGB_GREEN 1 /* Offset of Green */ 325#define RGB_BLUE 2 /* Offset of Blue */ 326#define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ 327 328 329/* Definitions for speed-related optimizations. */ 330 331 332/* If your compiler supports inline functions, define INLINE 333 * as the inline keyword; otherwise define it as empty. 334 */ 335 336#ifndef INLINE 337#ifdef __GNUC__ /* for instance, GNU C knows about inline */ 338#define INLINE __inline__ 339#endif 340#ifndef INLINE 341#define INLINE /* default is to define it as empty */ 342#endif 343#endif 344 345 346/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying 347 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER 348 * as short on such a machine. MULTIPLIER must be at least 16 bits wide. 349 */ 350 351#ifndef MULTIPLIER 352#define MULTIPLIER int /* type for fastest integer multiply */ 353#endif 354 355 356/* FAST_FLOAT should be either float or double, whichever is done faster 357 * by your compiler. (Note that this type is only used in the floating point 358 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) 359 * Typically, float is faster in ANSI C compilers, while double is faster in 360 * pre-ANSI compilers (because they insist on converting to double anyway). 361 * The code below therefore chooses float if we have ANSI-style prototypes. 362 */ 363 364#ifndef FAST_FLOAT 365#ifdef HAVE_PROTOTYPES 366#define FAST_FLOAT float 367#else 368#define FAST_FLOAT double 369#endif 370#endif 371 372#endif /* JPEG_INTERNAL_OPTIONS */ 373