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 * Modifications: 7 * Copyright (C) 2009, 2011, D. R. Commander. 8 * For conditions of distribution and use, see the accompanying README file. 9 * 10 * This file contains additional configuration options that customize the 11 * JPEG software for special applications or support machine-dependent 12 * optimizations. Most users will not need to touch this file. 13 */ 14 15 16/* 17 * Define BITS_IN_JSAMPLE as either 18 * 8 for 8-bit sample values (the usual setting) 19 * 12 for 12-bit sample values 20 * Only 8 and 12 are legal data precisions for lossy JPEG according to the 21 * JPEG standard, and the IJG code does not support anything else! 22 * We do not support run-time selection of data precision, sorry. 23 */ 24 25#define BITS_IN_JSAMPLE 8 /* use 8 or 12 */ 26 27 28/* 29 * Maximum number of components (color channels) allowed in JPEG image. 30 * To meet the letter of the JPEG spec, set this to 255. However, darn 31 * few applications need more than 4 channels (maybe 5 for CMYK + alpha 32 * mask). We recommend 10 as a reasonable compromise; use 4 if you are 33 * really short on memory. (Each allowed component costs a hundred or so 34 * bytes of storage, whether actually used in an image or not.) 35 */ 36 37#define MAX_COMPONENTS 10 /* maximum number of image components */ 38 39 40/* 41 * Basic data types. 42 * You may need to change these if you have a machine with unusual data 43 * type sizes; for example, "char" not 8 bits, "short" not 16 bits, 44 * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, 45 * but it had better be at least 16. 46 */ 47 48/* Representation of a single sample (pixel element value). 49 * We frequently allocate large arrays of these, so it's important to keep 50 * them small. But if you have memory to burn and access to char or short 51 * arrays is very slow on your hardware, you might want to change these. 52 */ 53 54#if BITS_IN_JSAMPLE == 8 55/* JSAMPLE should be the smallest type that will hold the values 0..255. 56 * You can use a signed char by having GETJSAMPLE mask it with 0xFF. 57 */ 58 59#ifdef HAVE_UNSIGNED_CHAR 60 61typedef unsigned char JSAMPLE; 62#define GETJSAMPLE(value) ((int) (value)) 63 64#else /* not HAVE_UNSIGNED_CHAR */ 65 66typedef char JSAMPLE; 67#ifdef __CHAR_UNSIGNED__ 68#define GETJSAMPLE(value) ((int) (value)) 69#else 70#define GETJSAMPLE(value) ((int) (value) & 0xFF) 71#endif /* __CHAR_UNSIGNED__ */ 72 73#endif /* HAVE_UNSIGNED_CHAR */ 74 75#define MAXJSAMPLE 255 76#define CENTERJSAMPLE 128 77 78#endif /* BITS_IN_JSAMPLE == 8 */ 79 80 81#if BITS_IN_JSAMPLE == 12 82/* JSAMPLE should be the smallest type that will hold the values 0..4095. 83 * On nearly all machines "short" will do nicely. 84 */ 85 86typedef short JSAMPLE; 87#define GETJSAMPLE(value) ((int) (value)) 88 89#define MAXJSAMPLE 4095 90#define CENTERJSAMPLE 2048 91 92#endif /* BITS_IN_JSAMPLE == 12 */ 93 94 95/* Representation of a DCT frequency coefficient. 96 * This should be a signed value of at least 16 bits; "short" is usually OK. 97 * Again, we allocate large arrays of these, but you can change to int 98 * if you have memory to burn and "short" is really slow. 99 */ 100 101typedef short JCOEF; 102 103 104/* Compressed datastreams are represented as arrays of JOCTET. 105 * These must be EXACTLY 8 bits wide, at least once they are written to 106 * external storage. Note that when using the stdio data source/destination 107 * managers, this is also the data type passed to fread/fwrite. 108 */ 109 110#ifdef HAVE_UNSIGNED_CHAR 111 112typedef unsigned char JOCTET; 113#define GETJOCTET(value) (value) 114 115#else /* not HAVE_UNSIGNED_CHAR */ 116 117typedef char JOCTET; 118#ifdef __CHAR_UNSIGNED__ 119#define GETJOCTET(value) (value) 120#else 121#define GETJOCTET(value) ((value) & 0xFF) 122#endif /* __CHAR_UNSIGNED__ */ 123 124#endif /* HAVE_UNSIGNED_CHAR */ 125 126 127/* These typedefs are used for various table entries and so forth. 128 * They must be at least as wide as specified; but making them too big 129 * won't cost a huge amount of memory, so we don't provide special 130 * extraction code like we did for JSAMPLE. (In other words, these 131 * typedefs live at a different point on the speed/space tradeoff curve.) 132 */ 133 134/* UINT8 must hold at least the values 0..255. */ 135 136#ifdef HAVE_UNSIGNED_CHAR 137typedef unsigned char UINT8; 138#else /* not HAVE_UNSIGNED_CHAR */ 139#ifdef __CHAR_UNSIGNED__ 140typedef char UINT8; 141#else /* not __CHAR_UNSIGNED__ */ 142typedef short UINT8; 143#endif /* __CHAR_UNSIGNED__ */ 144#endif /* HAVE_UNSIGNED_CHAR */ 145 146/* UINT16 must hold at least the values 0..65535. */ 147 148#ifdef HAVE_UNSIGNED_SHORT 149typedef unsigned short UINT16; 150#else /* not HAVE_UNSIGNED_SHORT */ 151typedef unsigned int UINT16; 152#endif /* HAVE_UNSIGNED_SHORT */ 153 154/* INT16 must hold at least the values -32768..32767. */ 155 156#ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ 157#ifndef _BASETSD_H_ /* basetsd.h correctly defines INT32 */ 158typedef short INT16; 159#endif 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#ifndef _BASETSD_H_ /* basetsd.h correctly defines INT32 */ 166typedef long INT32; 167#endif 168#endif 169 170/* Datatype used for image dimensions. The JPEG standard only supports 171 * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore 172 * "unsigned int" is sufficient on all machines. However, if you need to 173 * handle larger images and you don't mind deviating from the spec, you 174 * can change this datatype. 175 */ 176 177typedef unsigned int JDIMENSION; 178 179#define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ 180 181 182/* These macros are used in all function definitions and extern declarations. 183 * You could modify them if you need to change function linkage conventions; 184 * in particular, you'll need to do that to make the library a Windows DLL. 185 * Another application is to make all functions global for use with debuggers 186 * or code profilers that require it. 187 */ 188 189/* a function called through method pointers: */ 190#define METHODDEF(type) static type 191/* a function used only in its module: */ 192#define LOCAL(type) static type 193/* a function referenced thru EXTERNs: */ 194#define GLOBAL(type) type 195/* a reference to a GLOBAL function: */ 196#define EXTERN(type) extern type 197 198 199/* This macro is used to declare a "method", that is, a function pointer. 200 * We want to supply prototype parameters if the compiler can cope. 201 * Note that the arglist parameter must be parenthesized! 202 * Again, you can customize this if you need special linkage keywords. 203 */ 204 205#ifdef HAVE_PROTOTYPES 206#define JMETHOD(type,methodname,arglist) type (*methodname) arglist 207#else 208#define JMETHOD(type,methodname,arglist) type (*methodname) () 209#endif 210 211 212/* Here is the pseudo-keyword for declaring pointers that must be "far" 213 * on 80x86 machines. Most of the specialized coding for 80x86 is handled 214 * by just saying "FAR *" where such a pointer is needed. In a few places 215 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. 216 */ 217 218#ifndef FAR 219#ifdef NEED_FAR_POINTERS 220#ifndef FAR 221#define FAR far 222#endif 223#else 224#undef FAR 225#define FAR 226#endif 227#endif 228 229 230/* 231 * On a few systems, type boolean and/or its values FALSE, TRUE may appear 232 * in standard header files. Or you may have conflicts with application- 233 * specific header files that you want to include together with these files. 234 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. 235 */ 236 237#ifndef HAVE_BOOLEAN 238typedef int boolean; 239#endif 240#ifndef FALSE /* in case these macros already exist */ 241#define FALSE 0 /* values of boolean */ 242#endif 243#ifndef TRUE 244#define TRUE 1 245#endif 246 247 248/* 249 * The remaining options affect code selection within the JPEG library, 250 * but they don't need to be visible to most applications using the library. 251 * To minimize application namespace pollution, the symbols won't be 252 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. 253 */ 254 255#ifdef JPEG_INTERNALS 256#define JPEG_INTERNAL_OPTIONS 257#endif 258 259#ifdef JPEG_INTERNAL_OPTIONS 260 261 262/* 263 * These defines indicate whether to include various optional functions. 264 * Undefining some of these symbols will produce a smaller but less capable 265 * library. Note that you can leave certain source files out of the 266 * compilation/linking process if you've #undef'd the corresponding symbols. 267 * (You may HAVE to do that if your compiler doesn't like null source files.) 268 */ 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#define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ 275 276/* Encoder capability options: */ 277 278#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 279#define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 280#define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ 281/* Note: if you selected 12-bit data precision, it is dangerous to turn off 282 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit 283 * precision, so jchuff.c normally uses entropy optimization to compute 284 * usable tables for higher precision. If you don't want to do optimization, 285 * you'll have to supply different default Huffman tables. 286 * The exact same statements apply for progressive JPEG: the default tables 287 * don't work for progressive mode. (This may get fixed, however.) 288 */ 289#define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ 290 291/* Decoder capability options: */ 292 293#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 294#define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 295#define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ 296#define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ 297#define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ 298#undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ 299#define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ 300#define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ 301#define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ 302 303/* more capability options later, no doubt */ 304 305 306/* 307 * Ordering of RGB data in scanlines passed to or from the application. 308 * If your application wants to deal with data in the order B,G,R, just 309 * change these macros. You can also deal with formats such as R,G,B,X 310 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing 311 * the offsets will also change the order in which colormap data is organized. 312 * RESTRICTIONS: 313 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. 314 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not 315 * useful if you are using JPEG color spaces other than YCbCr or grayscale. 316 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE 317 * is not 3 (they don't understand about dummy color components!). So you 318 * can't use color quantization if you change that value. 319 */ 320 321#define RGB_RED 0 /* Offset of Red in an RGB scanline element */ 322#define RGB_GREEN 1 /* Offset of Green */ 323#define RGB_BLUE 2 /* Offset of Blue */ 324#define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ 325 326#define JPEG_NUMCS 16 327 328#define EXT_RGB_RED 0 329#define EXT_RGB_GREEN 1 330#define EXT_RGB_BLUE 2 331#define EXT_RGB_PIXELSIZE 3 332 333#define EXT_RGBX_RED 0 334#define EXT_RGBX_GREEN 1 335#define EXT_RGBX_BLUE 2 336#define EXT_RGBX_PIXELSIZE 4 337 338#define EXT_BGR_RED 2 339#define EXT_BGR_GREEN 1 340#define EXT_BGR_BLUE 0 341#define EXT_BGR_PIXELSIZE 3 342 343#define EXT_BGRX_RED 2 344#define EXT_BGRX_GREEN 1 345#define EXT_BGRX_BLUE 0 346#define EXT_BGRX_PIXELSIZE 4 347 348#define EXT_XBGR_RED 3 349#define EXT_XBGR_GREEN 2 350#define EXT_XBGR_BLUE 1 351#define EXT_XBGR_PIXELSIZE 4 352 353#define EXT_XRGB_RED 1 354#define EXT_XRGB_GREEN 2 355#define EXT_XRGB_BLUE 3 356#define EXT_XRGB_PIXELSIZE 4 357 358static const int rgb_red[JPEG_NUMCS] = { 359 -1, -1, RGB_RED, -1, -1, -1, EXT_RGB_RED, EXT_RGBX_RED, 360 EXT_BGR_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED, 361 EXT_RGBX_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED 362}; 363 364static const int rgb_green[JPEG_NUMCS] = { 365 -1, -1, RGB_GREEN, -1, -1, -1, EXT_RGB_GREEN, EXT_RGBX_GREEN, 366 EXT_BGR_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN, 367 EXT_RGBX_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN 368}; 369 370static const int rgb_blue[JPEG_NUMCS] = { 371 -1, -1, RGB_BLUE, -1, -1, -1, EXT_RGB_BLUE, EXT_RGBX_BLUE, 372 EXT_BGR_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE, 373 EXT_RGBX_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE 374}; 375 376static const int rgb_pixelsize[JPEG_NUMCS] = { 377 -1, -1, RGB_PIXELSIZE, -1, -1, -1, EXT_RGB_PIXELSIZE, EXT_RGBX_PIXELSIZE, 378 EXT_BGR_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE, 379 EXT_RGBX_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE 380}; 381 382/* Definitions for speed-related optimizations. */ 383 384/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying 385 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER 386 * as short on such a machine. MULTIPLIER must be at least 16 bits wide. 387 */ 388 389#ifndef MULTIPLIER 390#ifndef WITH_SIMD 391#define MULTIPLIER int /* type for fastest integer multiply */ 392#else 393#define MULTIPLIER short /* prefer 16-bit with SIMD for parellelism */ 394#endif 395#endif 396 397 398/* FAST_FLOAT should be either float or double, whichever is done faster 399 * by your compiler. (Note that this type is only used in the floating point 400 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) 401 * Typically, float is faster in ANSI C compilers, while double is faster in 402 * pre-ANSI compilers (because they insist on converting to double anyway). 403 * The code below therefore chooses float if we have ANSI-style prototypes. 404 */ 405 406#ifndef FAST_FLOAT 407#ifdef HAVE_PROTOTYPES 408#define FAST_FLOAT float 409#else 410#define FAST_FLOAT double 411#endif 412#endif 413 414#endif /* JPEG_INTERNAL_OPTIONS */ 415