workbench/libs/jpeg/jmorecfg.h

   1 /*
   2  * jmorecfg.h
   3  *
   4  * Copyright (C) 1991-1997, Thomas G. Lane.
   5  * Modified 1997-2012 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 /* The noreturn type identifier is used to declare functions
 214  * which cannot return.
 215  * Compilers can thus create more optimized code and perform
 216  * better checks for warnings and errors.
 217  * Static analyzer tools can make improved inferences about
 218  * execution paths and are prevented from giving false alerts.
 219  *
 220  * Unfortunately, the proposed specifications of corresponding
 221  * extensions in the Dec 2011 ISO C standard revision (C11),
 222  * GCC, MSVC, etc. are not viable.
 223  * Thus we introduce a user defined type to declare noreturn
 224  * functions at least for clarity.  A proper compiler would
 225  * have a suitable noreturn type to match in place of void.
 226  */
 227
 228 #ifndef HAVE_NORETURN_T
 229 typedef void noreturn_t;
 230 #endif
 231
 232
 233 /* Here is the pseudo-keyword for declaring pointers that must be "far"
 234  * on 80x86 machines.  Most of the specialized coding for 80x86 is handled
 235  * by just saying "FAR *" where such a pointer is needed.  In a few places
 236  * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
 237  */
 238
 239 #ifndef FAR
 240 #ifdef NEED_FAR_POINTERS
 241 #define FAR  far
 242 #else
 243 #define FAR
 244 #endif
 245 #endif
 246
 247
 248 /*
 249  * On a few systems, type boolean and/or its values FALSE, TRUE may appear
 250  * in standard header files.  Or you may have conflicts with application-
 251  * specific header files that you want to include together with these files.
 252  * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
 253  */
 254
 255 #ifdef __AROS__
 256   #ifndef FALSE
 257   #define FALSE 0
 258   #endif
 259   #ifndef TRUE
 260   #define TRUE  1
 261   #endif
 262   #ifndef HAVE_BOOLEAN
 263   typedef int boolean;
 264   #endif
 265 #else
 266   #ifdef HAVE_BOOLEAN
 267   #ifndef FALSE                 /* in case these macros already exist */
 268   #define FALSE 0               /* values of boolean */
 269   #endif
 270   #ifndef TRUE
 271   #define TRUE  1
 272   #endif
 273   #else
 274   typedef enum { FALSE = 0, TRUE = 1 } boolean;
 275   #endif
 276 #endif
 277
 278 /*
 279  * The remaining options affect code selection within the JPEG library,
 280  * but they don't need to be visible to most applications using the library.
 281  * To minimize application namespace pollution, the symbols won't be
 282  * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
 283  */
 284
 285 #ifdef JPEG_INTERNALS
 286 #define JPEG_INTERNAL_OPTIONS
 287 #endif
 288
 289 #ifdef JPEG_INTERNAL_OPTIONS
 290
 291
 292 /*
 293  * These defines indicate whether to include various optional functions.
 294  * Undefining some of these symbols will produce a smaller but less capable
 295  * library.  Note that you can leave certain source files out of the
 296  * compilation/linking process if you've #undef'd the corresponding symbols.
 297  * (You may HAVE to do that if your compiler doesn't like null source files.)
 298  */
 299
 300 /* Capability options common to encoder and decoder: */
 301
 302 #define DCT_ISLOW_SUPPORTED     /* slow but accurate integer algorithm */
 303 #define DCT_IFAST_SUPPORTED     /* faster, less accurate integer method */
 304 #define DCT_FLOAT_SUPPORTED     /* floating-point: accurate, fast on fast HW */
 305
 306 /* Encoder capability options: */
 307
 308 #define C_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
 309 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 310 #define C_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 311 #define DCT_SCALING_SUPPORTED       /* Input rescaling via DCT? (Requires DCT_ISLOW)*/
 312 #define ENTROPY_OPT_SUPPORTED       /* Optimization of entropy coding parms? */
 313 /* Note: if you selected 12-bit data precision, it is dangerous to turn off
 314  * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit
 315  * precision, so jchuff.c normally uses entropy optimization to compute
 316  * usable tables for higher precision.  If you don't want to do optimization,
 317  * you'll have to supply different default Huffman tables.
 318  * The exact same statements apply for progressive JPEG: the default tables
 319  * don't work for progressive mode.  (This may get fixed, however.)
 320  */
 321 #define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */
 322
 323 /* Decoder capability options: */
 324
 325 #define D_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
 326 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 327 #define D_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 328 #define IDCT_SCALING_SUPPORTED      /* Output rescaling via IDCT? */
 329 #define SAVE_MARKERS_SUPPORTED      /* jpeg_save_markers() needed? */
 330 #define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
 331 #undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
 332 #define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
 333 #define QUANT_1PASS_SUPPORTED       /* 1-pass color quantization? */
 334 #define QUANT_2PASS_SUPPORTED       /* 2-pass color quantization? */
 335
 336 /* more capability options later, no doubt */
 337
 338
 339 /*
 340  * Ordering of RGB data in scanlines passed to or from the application.
 341  * If your application wants to deal with data in the order B,G,R, just
 342  * change these macros.  You can also deal with formats such as R,G,B,X
 343  * (one extra byte per pixel) by changing RGB_PIXELSIZE.  Note that changing
 344  * the offsets will also change the order in which colormap data is organized.
 345  * RESTRICTIONS:
 346  * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
 347  * 2. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
 348  *    is not 3 (they don't understand about dummy color components!).  So you
 349  *    can't use color quantization if you change that value.
 350  */
 351
 352 #define RGB_RED         0       /* Offset of Red in an RGB scanline element */
 353 #define RGB_GREEN       1       /* Offset of Green */
 354 #define RGB_BLUE        2       /* Offset of Blue */
 355 #define RGB_PIXELSIZE   3       /* JSAMPLEs per RGB scanline element */
 356
 357
 358 /* Definitions for speed-related optimizations. */
 359
 360
 361 /* If your compiler supports inline functions, define INLINE
 362  * as the inline keyword; otherwise define it as empty.
 363  */
 364
 365 #ifndef INLINE
 366 #ifdef __GNUC__                 /* for instance, GNU C knows about inline */
 367 #define INLINE __inline__
 368 #endif
 369 #ifndef INLINE
 370 #define INLINE                  /* default is to define it as empty */
 371 #endif
 372 #endif
 373
 374
 375 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
 376  * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER
 377  * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.
 378  */
 379
 380 #ifndef MULTIPLIER
 381 #define MULTIPLIER  int         /* type for fastest integer multiply */
 382 #endif
 383
 384
 385 /* FAST_FLOAT should be either float or double, whichever is done faster
 386  * by your compiler.  (Note that this type is only used in the floating point
 387  * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
 388  * Typically, float is faster in ANSI C compilers, while double is faster in
 389  * pre-ANSI compilers (because they insist on converting to double anyway).
 390  * The code below therefore chooses float if we have ANSI-style prototypes.
 391  */
 392
 393 #ifndef FAST_FLOAT
 394 #ifdef HAVE_PROTOTYPES
 395 #define FAST_FLOAT  float
 396 #else
 397 #define FAST_FLOAT  double
 398 #endif
 399 #endif
 400
 401 #endif /* JPEG_INTERNAL_OPTIONS */