Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 1 | /* |
| 2 | * jmorecfg.h |
| 3 | * |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 4 | * Copyright (C) 1991-1997, Thomas G. Lane. |
Guido Vollbeding | 5996a25 | 2009-06-27 00:00:00 +0000 | [diff] [blame^] | 5 | * Modified 1997-2009 by Guido Vollbeding. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 6 | * This file is part of the Independent JPEG Group's software. |
| 7 | * For conditions of distribution and use, see the accompanying README file. |
| 8 | * |
| 9 | * This file contains additional configuration options that customize the |
| 10 | * JPEG software for special applications or support machine-dependent |
| 11 | * optimizations. Most users will not need to touch this file. |
| 12 | */ |
| 13 | |
| 14 | |
| 15 | /* |
| 16 | * Define BITS_IN_JSAMPLE as either |
| 17 | * 8 for 8-bit sample values (the usual setting) |
| 18 | * 12 for 12-bit sample values |
| 19 | * Only 8 and 12 are legal data precisions for lossy JPEG according to the |
| 20 | * JPEG standard, and the IJG code does not support anything else! |
| 21 | * We do not support run-time selection of data precision, sorry. |
| 22 | */ |
| 23 | |
| 24 | #define BITS_IN_JSAMPLE 8 /* use 8 or 12 */ |
| 25 | |
| 26 | |
| 27 | /* |
| 28 | * Maximum number of components (color channels) allowed in JPEG image. |
| 29 | * To meet the letter of the JPEG spec, set this to 255. However, darn |
| 30 | * few applications need more than 4 channels (maybe 5 for CMYK + alpha |
| 31 | * mask). We recommend 10 as a reasonable compromise; use 4 if you are |
| 32 | * really short on memory. (Each allowed component costs a hundred or so |
| 33 | * bytes of storage, whether actually used in an image or not.) |
| 34 | */ |
| 35 | |
| 36 | #define MAX_COMPONENTS 10 /* maximum number of image components */ |
| 37 | |
| 38 | |
| 39 | /* |
| 40 | * Basic data types. |
| 41 | * You may need to change these if you have a machine with unusual data |
| 42 | * type sizes; for example, "char" not 8 bits, "short" not 16 bits, |
| 43 | * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, |
| 44 | * but it had better be at least 16. |
| 45 | */ |
| 46 | |
| 47 | /* Representation of a single sample (pixel element value). |
| 48 | * We frequently allocate large arrays of these, so it's important to keep |
| 49 | * them small. But if you have memory to burn and access to char or short |
| 50 | * arrays is very slow on your hardware, you might want to change these. |
| 51 | */ |
| 52 | |
| 53 | #if BITS_IN_JSAMPLE == 8 |
| 54 | /* JSAMPLE should be the smallest type that will hold the values 0..255. |
| 55 | * You can use a signed char by having GETJSAMPLE mask it with 0xFF. |
| 56 | */ |
| 57 | |
| 58 | #ifdef HAVE_UNSIGNED_CHAR |
| 59 | |
| 60 | typedef unsigned char JSAMPLE; |
| 61 | #define GETJSAMPLE(value) ((int) (value)) |
| 62 | |
| 63 | #else /* not HAVE_UNSIGNED_CHAR */ |
| 64 | |
| 65 | typedef char JSAMPLE; |
| 66 | #ifdef CHAR_IS_UNSIGNED |
| 67 | #define GETJSAMPLE(value) ((int) (value)) |
| 68 | #else |
| 69 | #define GETJSAMPLE(value) ((int) (value) & 0xFF) |
| 70 | #endif /* CHAR_IS_UNSIGNED */ |
| 71 | |
| 72 | #endif /* HAVE_UNSIGNED_CHAR */ |
| 73 | |
| 74 | #define MAXJSAMPLE 255 |
| 75 | #define CENTERJSAMPLE 128 |
| 76 | |
| 77 | #endif /* BITS_IN_JSAMPLE == 8 */ |
| 78 | |
| 79 | |
| 80 | #if BITS_IN_JSAMPLE == 12 |
| 81 | /* JSAMPLE should be the smallest type that will hold the values 0..4095. |
| 82 | * On nearly all machines "short" will do nicely. |
| 83 | */ |
| 84 | |
| 85 | typedef short JSAMPLE; |
| 86 | #define GETJSAMPLE(value) ((int) (value)) |
| 87 | |
| 88 | #define MAXJSAMPLE 4095 |
| 89 | #define CENTERJSAMPLE 2048 |
| 90 | |
| 91 | #endif /* BITS_IN_JSAMPLE == 12 */ |
| 92 | |
| 93 | |
| 94 | /* Representation of a DCT frequency coefficient. |
| 95 | * This should be a signed value of at least 16 bits; "short" is usually OK. |
| 96 | * Again, we allocate large arrays of these, but you can change to int |
| 97 | * if you have memory to burn and "short" is really slow. |
| 98 | */ |
| 99 | |
| 100 | typedef short JCOEF; |
| 101 | |
| 102 | |
| 103 | /* Compressed datastreams are represented as arrays of JOCTET. |
| 104 | * These must be EXACTLY 8 bits wide, at least once they are written to |
| 105 | * external storage. Note that when using the stdio data source/destination |
| 106 | * managers, this is also the data type passed to fread/fwrite. |
| 107 | */ |
| 108 | |
| 109 | #ifdef HAVE_UNSIGNED_CHAR |
| 110 | |
| 111 | typedef unsigned char JOCTET; |
| 112 | #define GETJOCTET(value) (value) |
| 113 | |
| 114 | #else /* not HAVE_UNSIGNED_CHAR */ |
| 115 | |
| 116 | typedef char JOCTET; |
| 117 | #ifdef CHAR_IS_UNSIGNED |
| 118 | #define GETJOCTET(value) (value) |
| 119 | #else |
| 120 | #define GETJOCTET(value) ((value) & 0xFF) |
| 121 | #endif /* CHAR_IS_UNSIGNED */ |
| 122 | |
| 123 | #endif /* HAVE_UNSIGNED_CHAR */ |
| 124 | |
| 125 | |
| 126 | /* These typedefs are used for various table entries and so forth. |
| 127 | * They must be at least as wide as specified; but making them too big |
| 128 | * won't cost a huge amount of memory, so we don't provide special |
| 129 | * extraction code like we did for JSAMPLE. (In other words, these |
| 130 | * typedefs live at a different point on the speed/space tradeoff curve.) |
| 131 | */ |
| 132 | |
| 133 | /* UINT8 must hold at least the values 0..255. */ |
| 134 | |
| 135 | #ifdef HAVE_UNSIGNED_CHAR |
| 136 | typedef unsigned char UINT8; |
| 137 | #else /* not HAVE_UNSIGNED_CHAR */ |
| 138 | #ifdef CHAR_IS_UNSIGNED |
| 139 | typedef char UINT8; |
| 140 | #else /* not CHAR_IS_UNSIGNED */ |
| 141 | typedef short UINT8; |
| 142 | #endif /* CHAR_IS_UNSIGNED */ |
| 143 | #endif /* HAVE_UNSIGNED_CHAR */ |
| 144 | |
| 145 | /* UINT16 must hold at least the values 0..65535. */ |
| 146 | |
| 147 | #ifdef HAVE_UNSIGNED_SHORT |
| 148 | typedef unsigned short UINT16; |
| 149 | #else /* not HAVE_UNSIGNED_SHORT */ |
| 150 | typedef unsigned int UINT16; |
| 151 | #endif /* HAVE_UNSIGNED_SHORT */ |
| 152 | |
| 153 | /* INT16 must hold at least the values -32768..32767. */ |
| 154 | |
| 155 | #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ |
| 156 | typedef short INT16; |
| 157 | #endif |
| 158 | |
| 159 | /* INT32 must hold at least signed 32-bit values. */ |
| 160 | |
| 161 | #ifndef XMD_H /* X11/xmd.h correctly defines INT32 */ |
Guido Vollbeding | 5996a25 | 2009-06-27 00:00:00 +0000 | [diff] [blame^] | 162 | #ifndef _BASETSD_H_ /* Microsoft defines it in basetsd.h */ |
| 163 | #ifndef QGLOBAL_H /* Qt defines it in qglobal.h */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 164 | typedef long INT32; |
| 165 | #endif |
Guido Vollbeding | 5996a25 | 2009-06-27 00:00:00 +0000 | [diff] [blame^] | 166 | #endif |
| 167 | #endif |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 168 | |
| 169 | /* Datatype used for image dimensions. The JPEG standard only supports |
| 170 | * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore |
| 171 | * "unsigned int" is sufficient on all machines. However, if you need to |
| 172 | * handle larger images and you don't mind deviating from the spec, you |
| 173 | * can change this datatype. |
| 174 | */ |
| 175 | |
| 176 | typedef unsigned int JDIMENSION; |
| 177 | |
| 178 | #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ |
| 179 | |
| 180 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 181 | /* These macros are used in all function definitions and extern declarations. |
| 182 | * You could modify them if you need to change function linkage conventions; |
| 183 | * in particular, you'll need to do that to make the library a Windows DLL. |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 184 | * Another application is to make all functions global for use with debuggers |
| 185 | * or code profilers that require it. |
| 186 | */ |
| 187 | |
Thomas G. Lane | 489583f | 1996-02-07 00:00:00 +0000 | [diff] [blame] | 188 | /* a function called through method pointers: */ |
| 189 | #define METHODDEF(type) static type |
| 190 | /* a function used only in its module: */ |
| 191 | #define LOCAL(type) static type |
| 192 | /* a function referenced thru EXTERNs: */ |
| 193 | #define GLOBAL(type) type |
| 194 | /* a reference to a GLOBAL function: */ |
| 195 | #define EXTERN(type) extern type |
| 196 | |
| 197 | |
| 198 | /* This macro is used to declare a "method", that is, a function pointer. |
| 199 | * We want to supply prototype parameters if the compiler can cope. |
| 200 | * Note that the arglist parameter must be parenthesized! |
| 201 | * Again, you can customize this if you need special linkage keywords. |
| 202 | */ |
| 203 | |
| 204 | #ifdef HAVE_PROTOTYPES |
| 205 | #define JMETHOD(type,methodname,arglist) type (*methodname) arglist |
| 206 | #else |
| 207 | #define JMETHOD(type,methodname,arglist) type (*methodname) () |
| 208 | #endif |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 209 | |
| 210 | |
| 211 | /* Here is the pseudo-keyword for declaring pointers that must be "far" |
| 212 | * on 80x86 machines. Most of the specialized coding for 80x86 is handled |
| 213 | * by just saying "FAR *" where such a pointer is needed. In a few places |
| 214 | * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. |
| 215 | */ |
| 216 | |
Guido Vollbeding | 5996a25 | 2009-06-27 00:00:00 +0000 | [diff] [blame^] | 217 | #ifndef FAR |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 218 | #ifdef NEED_FAR_POINTERS |
| 219 | #define FAR far |
| 220 | #else |
| 221 | #define FAR |
| 222 | #endif |
Guido Vollbeding | 5996a25 | 2009-06-27 00:00:00 +0000 | [diff] [blame^] | 223 | #endif |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 224 | |
| 225 | |
| 226 | /* |
| 227 | * On a few systems, type boolean and/or its values FALSE, TRUE may appear |
| 228 | * in standard header files. Or you may have conflicts with application- |
| 229 | * specific header files that you want to include together with these files. |
| 230 | * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. |
| 231 | */ |
| 232 | |
| 233 | #ifndef HAVE_BOOLEAN |
| 234 | typedef int boolean; |
| 235 | #endif |
| 236 | #ifndef FALSE /* in case these macros already exist */ |
| 237 | #define FALSE 0 /* values of boolean */ |
| 238 | #endif |
| 239 | #ifndef TRUE |
| 240 | #define TRUE 1 |
| 241 | #endif |
| 242 | |
| 243 | |
| 244 | /* |
| 245 | * The remaining options affect code selection within the JPEG library, |
| 246 | * but they don't need to be visible to most applications using the library. |
| 247 | * To minimize application namespace pollution, the symbols won't be |
| 248 | * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. |
| 249 | */ |
| 250 | |
| 251 | #ifdef JPEG_INTERNALS |
| 252 | #define JPEG_INTERNAL_OPTIONS |
| 253 | #endif |
| 254 | |
| 255 | #ifdef JPEG_INTERNAL_OPTIONS |
| 256 | |
| 257 | |
| 258 | /* |
| 259 | * These defines indicate whether to include various optional functions. |
| 260 | * Undefining some of these symbols will produce a smaller but less capable |
| 261 | * library. Note that you can leave certain source files out of the |
| 262 | * compilation/linking process if you've #undef'd the corresponding symbols. |
| 263 | * (You may HAVE to do that if your compiler doesn't like null source files.) |
| 264 | */ |
| 265 | |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 266 | /* Capability options common to encoder and decoder: */ |
| 267 | |
| 268 | #define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ |
| 269 | #define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ |
| 270 | #define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ |
| 271 | |
| 272 | /* Encoder capability options: */ |
| 273 | |
Guido Vollbeding | 1e247ac | 1998-03-28 00:00:00 +0000 | [diff] [blame] | 274 | #define C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 275 | #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ |
| 276 | #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ |
Guido Vollbeding | 5996a25 | 2009-06-27 00:00:00 +0000 | [diff] [blame^] | 277 | #define DCT_SCALING_SUPPORTED /* Input rescaling via DCT? (Requires DCT_ISLOW)*/ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 278 | #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ |
| 279 | /* Note: if you selected 12-bit data precision, it is dangerous to turn off |
| 280 | * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit |
| 281 | * precision, so jchuff.c normally uses entropy optimization to compute |
| 282 | * usable tables for higher precision. If you don't want to do optimization, |
| 283 | * you'll have to supply different default Huffman tables. |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 284 | * The exact same statements apply for progressive JPEG: the default tables |
| 285 | * don't work for progressive mode. (This may get fixed, however.) |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 286 | */ |
| 287 | #define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ |
| 288 | |
| 289 | /* Decoder capability options: */ |
| 290 | |
Guido Vollbeding | 1e247ac | 1998-03-28 00:00:00 +0000 | [diff] [blame] | 291 | #define D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 292 | #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 293 | #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ |
Guido Vollbeding | 5996a25 | 2009-06-27 00:00:00 +0000 | [diff] [blame^] | 294 | #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ |
Thomas G. Lane | 5ead57a | 1998-03-27 00:00:00 +0000 | [diff] [blame] | 295 | #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ |
Thomas G. Lane | bc79e06 | 1995-08-02 00:00:00 +0000 | [diff] [blame] | 296 | #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ |
Thomas G. Lane | 36a4ccc | 1994-09-24 00:00:00 +0000 | [diff] [blame] | 297 | #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ |
| 298 | #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ |
| 299 | #define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ |
| 300 | #define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ |
| 301 | |
| 302 | /* more capability options later, no doubt */ |
| 303 | |
| 304 | |
| 305 | /* |
| 306 | * Ordering of RGB data in scanlines passed to or from the application. |
| 307 | * If your application wants to deal with data in the order B,G,R, just |
| 308 | * change these macros. You can also deal with formats such as R,G,B,X |
| 309 | * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing |
| 310 | * the offsets will also change the order in which colormap data is organized. |
| 311 | * RESTRICTIONS: |
| 312 | * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. |
| 313 | * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not |
| 314 | * useful if you are using JPEG color spaces other than YCbCr or grayscale. |
| 315 | * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE |
| 316 | * is not 3 (they don't understand about dummy color components!). So you |
| 317 | * can't use color quantization if you change that value. |
| 318 | */ |
| 319 | |
| 320 | #define RGB_RED 0 /* Offset of Red in an RGB scanline element */ |
| 321 | #define RGB_GREEN 1 /* Offset of Green */ |
| 322 | #define RGB_BLUE 2 /* Offset of Blue */ |
| 323 | #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ |
| 324 | |
| 325 | |
| 326 | /* Definitions for speed-related optimizations. */ |
| 327 | |
| 328 | |
| 329 | /* If your compiler supports inline functions, define INLINE |
| 330 | * as the inline keyword; otherwise define it as empty. |
| 331 | */ |
| 332 | |
| 333 | #ifndef INLINE |
| 334 | #ifdef __GNUC__ /* for instance, GNU C knows about inline */ |
| 335 | #define INLINE __inline__ |
| 336 | #endif |
| 337 | #ifndef INLINE |
| 338 | #define INLINE /* default is to define it as empty */ |
| 339 | #endif |
| 340 | #endif |
| 341 | |
| 342 | |
| 343 | /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying |
| 344 | * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER |
| 345 | * as short on such a machine. MULTIPLIER must be at least 16 bits wide. |
| 346 | */ |
| 347 | |
| 348 | #ifndef MULTIPLIER |
| 349 | #define MULTIPLIER int /* type for fastest integer multiply */ |
| 350 | #endif |
| 351 | |
| 352 | |
| 353 | /* FAST_FLOAT should be either float or double, whichever is done faster |
| 354 | * by your compiler. (Note that this type is only used in the floating point |
| 355 | * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) |
| 356 | * Typically, float is faster in ANSI C compilers, while double is faster in |
| 357 | * pre-ANSI compilers (because they insist on converting to double anyway). |
| 358 | * The code below therefore chooses float if we have ANSI-style prototypes. |
| 359 | */ |
| 360 | |
| 361 | #ifndef FAST_FLOAT |
| 362 | #ifdef HAVE_PROTOTYPES |
| 363 | #define FAST_FLOAT float |
| 364 | #else |
| 365 | #define FAST_FLOAT double |
| 366 | #endif |
| 367 | #endif |
| 368 | |
| 369 | #endif /* JPEG_INTERNAL_OPTIONS */ |