workbench/libs/jpeg/jmorecfg.h

   1 /*
   2  * jmorecfg.h
   3  *
   4  * Copyright (C) 1991-1997, Thomas G. Lane.
   5  * Modified 1997-2011 by Guido Vollbeding.
   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 */
 162 #ifndef _BASETSD_H_             /* Microsoft defines it in basetsd.h */
 163 #ifndef _BASETSD_H              /* MinGW is slightly different */
 164 #ifndef QGLOBAL_H               /* Qt defines it in qglobal.h */
 165 typedef long INT32;
 166 #endif
 167 #endif
 168 #endif
 169 #endif
 170
 171 /* Datatype used for image dimensions.  The JPEG standard only supports
 172  * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore
 173  * "unsigned int" is sufficient on all machines.  However, if you need to
 174  * handle larger images and you don't mind deviating from the spec, you
 175  * can change this datatype.
 176  */
 177
 178 typedef unsigned int JDIMENSION;
 179
 180 #define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */
 181
 182
 183 /* These macros are used in all function definitions and extern declarations.
 184  * You could modify them if you need to change function linkage conventions;
 185  * in particular, you'll need to do that to make the library a Windows DLL.
 186  * Another application is to make all functions global for use with debuggers
 187  * or code profilers that require it.
 188  */
 189
 190 /* a function called through method pointers: */
 191 #define METHODDEF(type)         static type
 192 /* a function used only in its module: */
 193 #define LOCAL(type)             static type
 194 /* a function referenced thru EXTERNs: */
 195 #define GLOBAL(type)            type
 196 /* a reference to a GLOBAL function: */
 197 #define EXTERN(type)            extern type
 198
 199
 200 /* This macro is used to declare a "method", that is, a function pointer.
 201  * We want to supply prototype parameters if the compiler can cope.
 202  * Note that the arglist parameter must be parenthesized!
 203  * Again, you can customize this if you need special linkage keywords.
 204  */
 205
 206 #ifdef HAVE_PROTOTYPES
 207 #define JMETHOD(type,methodname,arglist)  type (*methodname) arglist
 208 #else
 209 #define JMETHOD(type,methodname,arglist)  type (*methodname) ()
 210 #endif
 211
 212
 213 /* Here is the pseudo-keyword for declaring pointers that must be "far"
 214  * on 80x86 machines.  Most of the specialized coding for 80x86 is handled
 215  * by just saying "FAR *" where such a pointer is needed.  In a few places
 216  * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
 217  */
 218
 219 #ifndef FAR
 220 #ifdef NEED_FAR_POINTERS
 221 #define FAR  far
 222 #else
 223 #define FAR
 224 #endif
 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
 236 typedef 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 /* Capability options common to encoder and decoder: */
 269
 270 #define DCT_ISLOW_SUPPORTED     /* slow but accurate integer algorithm */
 271 #define DCT_IFAST_SUPPORTED     /* faster, less accurate integer method */
 272 #define DCT_FLOAT_SUPPORTED     /* floating-point: accurate, fast on fast HW */
 273
 274 /* Encoder capability options: */
 275
 276 #define C_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
 277 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 278 #define C_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 279 #define DCT_SCALING_SUPPORTED       /* Input rescaling via DCT? (Requires DCT_ISLOW)*/
 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_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
 294 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 295 #define D_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 296 #define IDCT_SCALING_SUPPORTED      /* Output rescaling via IDCT? */
 297 #define SAVE_MARKERS_SUPPORTED      /* jpeg_save_markers() needed? */
 298 #define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
 299 #undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
 300 #define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
 301 #define QUANT_1PASS_SUPPORTED       /* 1-pass color quantization? */
 302 #define QUANT_2PASS_SUPPORTED       /* 2-pass color quantization? */
 303
 304 /* more capability options later, no doubt */
 305
 306
 307 /*
 308  * Ordering of RGB data in scanlines passed to or from the application.
 309  * If your application wants to deal with data in the order B,G,R, just
 310  * change these macros.  You can also deal with formats such as R,G,B,X
 311  * (one extra byte per pixel) by changing RGB_PIXELSIZE.  Note that changing
 312  * the offsets will also change the order in which colormap data is organized.
 313  * RESTRICTIONS:
 314  * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
 315  * 2. 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 */