jpeg/jmorecfg.h

   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 /*
  14  * This file has been modified for the Mozilla/Netscape environment.
  15  * Modifications are distributed under the mozilla.org tri-license and are
  16  * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
  17  * Reserved. See http://www.mozilla.org/MPL/
  18  */
  19
  20
  21 /*
  22  * Define BITS_IN_JSAMPLE as either
  23  *   8   for 8-bit sample values (the usual setting)
  24  *   12  for 12-bit sample values
  25  * Only 8 and 12 are legal data precisions for lossy JPEG according to the
  26  * JPEG standard, and the IJG code does not support anything else!
  27  * We do not support run-time selection of data precision, sorry.
  28  */
  29
  30 #define BITS_IN_JSAMPLE  8      /* use 8 or 12 */
  31
  32
  33 /*
  34  * Maximum number of components (color channels) allowed in JPEG image.
  35  * To meet the letter of the JPEG spec, set this to 255.  However, darn
  36  * few applications need more than 4 channels (maybe 5 for CMYK + alpha
  37  * mask).  We recommend 10 as a reasonable compromise; use 4 if you are
  38  * really short on memory.  (Each allowed component costs a hundred or so
  39  * bytes of storage, whether actually used in an image or not.)
  40  */
  41
  42 #define MAX_COMPONENTS  10      /* maximum number of image components */
  43
  44
  45 /*
  46  * Basic data types.
  47  * You may need to change these if you have a machine with unusual data
  48  * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
  49  * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits,
  50  * but it had better be at least 16.
  51  */
  52
  53 /* Representation of a single sample (pixel element value).
  54  * We frequently allocate large arrays of these, so it's important to keep
  55  * them small.  But if you have memory to burn and access to char or short
  56  * arrays is very slow on your hardware, you might want to change these.
  57  */
  58
  59 #if BITS_IN_JSAMPLE == 8
  60 /* JSAMPLE should be the smallest type that will hold the values 0..255.
  61  * You can use a signed char by having GETJSAMPLE mask it with 0xFF.
  62  */
  63
  64 #ifdef HAVE_UNSIGNED_CHAR
  65
  66 typedef unsigned char JSAMPLE;
  67 #define GETJSAMPLE(value)  ((int) (value))
  68
  69 #else /* not HAVE_UNSIGNED_CHAR */
  70
  71 typedef char JSAMPLE;
  72 #ifdef CHAR_IS_UNSIGNED
  73 #define GETJSAMPLE(value)  ((int) (value))
  74 #else
  75 #define GETJSAMPLE(value)  ((int) (value) & 0xFF)
  76 #endif /* CHAR_IS_UNSIGNED */
  77
  78 #endif /* HAVE_UNSIGNED_CHAR */
  79
  80 #define MAXJSAMPLE      255
  81 #define CENTERJSAMPLE   128
  82
  83 #endif /* BITS_IN_JSAMPLE == 8 */
  84
  85
  86 #if BITS_IN_JSAMPLE == 12
  87 /* JSAMPLE should be the smallest type that will hold the values 0..4095.
  88  * On nearly all machines "short" will do nicely.
  89  */
  90
  91 typedef short JSAMPLE;
  92 #define GETJSAMPLE(value)  ((int) (value))
  93
  94 #define MAXJSAMPLE      4095
  95 #define CENTERJSAMPLE   2048
  96
  97 #endif /* BITS_IN_JSAMPLE == 12 */
  98
  99
 100 /* Representation of a DCT frequency coefficient.
 101  * This should be a signed value of at least 16 bits; "short" is usually OK.
 102  * Again, we allocate large arrays of these, but you can change to int
 103  * if you have memory to burn and "short" is really slow.
 104  */
 105
 106 typedef short JCOEF;
 107
 108 /* Defines for MMX/SSE2 support. */
 109
 110 #if defined(XP_WIN32) && defined(_M_IX86) && !defined(__GNUC__)
 111 #define HAVE_MMX_INTEL_MNEMONICS
 112
 113 /* SSE2 code appears broken for some cpus (bug 247437) */
 114 #define HAVE_SSE2_INTEL_MNEMONICS
 115 #define HAVE_SSE2_INTRINSICS
 116 #endif
 117
 118 #if defined(__GNUC__) && defined(__i386__)
 119 #if defined(XP_MACOSX)
 120 #define HAVE_SSE2_INTRINSICS
 121 #endif /* ! XP_MACOSX */
 122 #endif /* ! GNUC && i386 */
 123
 124 /* Add support for other platforms here */
 125
 126
 127 /* Compressed datastreams are represented as arrays of JOCTET.
 128  * These must be EXACTLY 8 bits wide, at least once they are written to
 129  * external storage.  Note that when using the stdio data source/destination
 130  * managers, this is also the data type passed to fread/fwrite.
 131  */
 132
 133 #ifdef HAVE_UNSIGNED_CHAR
 134
 135 typedef unsigned char JOCTET;
 136 #define GETJOCTET(value)  (value)
 137
 138 #else /* not HAVE_UNSIGNED_CHAR */
 139
 140 typedef char JOCTET;
 141 #ifdef CHAR_IS_UNSIGNED
 142 #define GETJOCTET(value)  (value)
 143 #else
 144 #define GETJOCTET(value)  ((value) & 0xFF)
 145 #endif /* CHAR_IS_UNSIGNED */
 146
 147 #endif /* HAVE_UNSIGNED_CHAR */
 148
 149
 150 /* These typedefs are used for various table entries and so forth.
 151  * They must be at least as wide as specified; but making them too big
 152  * won't cost a huge amount of memory, so we don't provide special
 153  * extraction code like we did for JSAMPLE.  (In other words, these
 154  * typedefs live at a different point on the speed/space tradeoff curve.)
 155  */
 156
 157 /* UINT8 must hold at least the values 0..255. */
 158
 159 #ifdef HAVE_UNSIGNED_CHAR
 160 typedef unsigned char UINT8;
 161 #else /* not HAVE_UNSIGNED_CHAR */
 162 #ifdef CHAR_IS_UNSIGNED
 163 typedef char UINT8;
 164 #else /* not CHAR_IS_UNSIGNED */
 165 typedef short UINT8;
 166 #endif /* CHAR_IS_UNSIGNED */
 167 #endif /* HAVE_UNSIGNED_CHAR */
 168
 169 /* UINT16 must hold at least the values 0..65535. */
 170
 171 #ifdef HAVE_UNSIGNED_SHORT
 172 typedef unsigned short UINT16;
 173 #else /* not HAVE_UNSIGNED_SHORT */
 174 typedef unsigned int UINT16;
 175 #endif /* HAVE_UNSIGNED_SHORT */
 176
 177 /* INT16 must hold at least the values -32768..32767. */
 178
 179 #ifndef XMD_H                   /* X11/xmd.h correctly defines INT16 */
 180 typedef short INT16;
 181 #endif
 182
 183 /* INT32 must hold at least signed 32-bit values. */
 184
 185 #ifndef XMD_H                   /* X11/xmd.h correctly defines INT32 */
 186 #ifndef _BASETSD_H_             /* basetsd.h correctly defines INT32 */
 187 #ifndef _BASETSD_H
 188 typedef long INT32;
 189 #endif
 190 #endif
 191 #endif
 192
 193 /* Datatype used for image dimensions.  The JPEG standard only supports
 194  * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore
 195  * "unsigned int" is sufficient on all machines.  However, if you need to
 196  * handle larger images and you don't mind deviating from the spec, you
 197  * can change this datatype.
 198  */
 199
 200 typedef unsigned int JDIMENSION;
 201
 202 #define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */
 203
 204
 205 /* These macros are used in all function definitions and extern declarations.
 206  * You could modify them if you need to change function linkage conventions;
 207  * in particular, you'll need to do that to make the library a Windows DLL.
 208  * Another application is to make all functions global for use with debuggers
 209  * or code profilers that require it.
 210  */
 211
 212 /* Mozilla mod: make external functions be DLL-able via JRI_PUBLIC_API(),
 213  * and supply extern "C" for C++ users of the C-compiled IJG library.
 214  * (Well, not anymore, but there's still a modification here.)
 215  */
 216 #include "prtypes.h"
 217
 218 /* a function called through method pointers: */
 219 #define METHODDEF(type)         static type
 220 /* a function used only in its module: */
 221 #define LOCAL(type)             static type
 222
 223 PR_BEGIN_EXTERN_C
 224 #define GLOBAL(type) type
 225 #define EXTERN(type) extern type
 226 PR_END_EXTERN_C
 227
 228
 229 /* This macro is used to declare a "method", that is, a function pointer.
 230  * We want to supply prototype parameters if the compiler can cope.
 231  * Note that the arglist parameter must be parenthesized!
 232  * Again, you can customize this if you need special linkage keywords.
 233  */
 234
 235 #ifdef HAVE_PROTOTYPES
 236 #define JMETHOD(type,methodname,arglist)  type (*methodname) arglist
 237 #else
 238 #define JMETHOD(type,methodname,arglist)  type (*methodname) ()
 239 #endif
 240
 241
 242 /* Here is the pseudo-keyword for declaring pointers that must be "far"
 243  * on 80x86 machines.  Most of the specialized coding for 80x86 is handled
 244  * by just saying "FAR *" where such a pointer is needed.  In a few places
 245  * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
 246  */
 247
 248 #ifndef FAR
 249 #ifdef NEED_FAR_POINTERS
 250 #define FAR  far
 251 #else
 252 #define FAR
 253 #endif
 254 #endif
 255
 256
 257 /*
 258  * On a few systems, type boolean and/or its values FALSE, TRUE may appear
 259  * in standard header files.  Or you may have conflicts with application-
 260  * specific header files that you want to include together with these files.
 261  * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
 262  */
 263
 264 /* Mozilla mod: IJG distribution makes boolean = int, but on Windows
 265  * it's far safer to define boolean = unsigned char.  Easier to switch
 266  * than fight.
 267  */
 268
 269 /* For some reason, on SunOS 5.3 HAVE_BOOLEAN gets defined when using
 270  * gcc, but boolean doesn't.  Even if you use -UHAVE_BOOLEAN, it still
 271  * gets reset somewhere.
 272  */
 273 #if defined(MUST_UNDEF_HAVE_BOOLEAN_AFTER_INCLUDES) && defined(HAVE_BOOLEAN)
 274 #undef HAVE_BOOLEAN
 275 #endif
 276 #ifndef HAVE_BOOLEAN
 277 typedef unsigned char boolean;
 278 #endif
 279 #ifndef FALSE                   /* in case these macros already exist */
 280 #define FALSE   0               /* values of boolean */
 281 #endif
 282 #ifndef TRUE
 283 #define TRUE    1
 284 #endif
 285
 286
 287 /*
 288  * The remaining options affect code selection within the JPEG library,
 289  * but they don't need to be visible to most applications using the library.
 290  * To minimize application namespace pollution, the symbols won't be
 291  * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
 292  */
 293
 294 #ifdef JPEG_INTERNALS
 295 #define JPEG_INTERNAL_OPTIONS
 296 #endif
 297
 298 #ifdef JPEG_INTERNAL_OPTIONS
 299
 300
 301 /*
 302  * These defines indicate whether to include various optional functions.
 303  * Undefining some of these symbols will produce a smaller but less capable
 304  * library.  Note that you can leave certain source files out of the
 305  * compilation/linking process if you've #undef'd the corresponding symbols.
 306  * (You may HAVE to do that if your compiler doesn't like null source files.)
 307  */
 308
 309 /*
 310  * Mozilla mods here: undef some features not actually used by the browser.
 311  * This reduces object code size and more importantly allows us to compile
 312  * even with broken compilers that crash when fed certain modules of the
 313  * IJG sources.  Currently we undef:
 314  * DCT_FLOAT_SUPPORTED INPUT_SMOOTHING_SUPPORTED IDCT_SCALING_SUPPORTED
 315  * QUANT_1PASS_SUPPORTED QUANT_2PASS_SUPPORTED
 316  */
 317
 318 /* Arithmetic coding is unsupported for legal reasons.  Complaints to IBM. */
 319
 320 /* Capability options common to encoder and decoder: */
 321
 322 #define DCT_ISLOW_SUPPORTED     /* slow but accurate integer algorithm */
 323 #undef  DCT_IFAST_SUPPORTED     /* faster, less accurate integer method */
 324 #undef  DCT_FLOAT_SUPPORTED     /* floating-point: accurate, fast on fast HW */
 325
 326 /* Encoder capability options: */
 327
 328 #undef  C_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
 329 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 330 #define C_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 331 #define ENTROPY_OPT_SUPPORTED       /* Optimization of entropy coding parms? */
 332 /* Note: if you selected 12-bit data precision, it is dangerous to turn off
 333  * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit
 334  * precision, so jchuff.c normally uses entropy optimization to compute
 335  * usable tables for higher precision.  If you don't want to do optimization,
 336  * you'll have to supply different default Huffman tables.
 337  * The exact same statements apply for progressive JPEG: the default tables
 338  * don't work for progressive mode.  (This may get fixed, however.)
 339  */
 340 #undef  INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */
 341
 342 /* Decoder capability options: */
 343
 344 #undef  D_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
 345 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 346 #define D_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 347 #define SAVE_MARKERS_SUPPORTED      /* jpeg_save_markers() needed? */
 348 #define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
 349 #undef  IDCT_SCALING_SUPPORTED      /* Output rescaling via IDCT? */
 350 #undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
 351 #define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
 352 #undef  QUANT_1PASS_SUPPORTED       /* 1-pass color quantization? */
 353 #undef  QUANT_2PASS_SUPPORTED       /* 2-pass color quantization? */
 354
 355 /* more capability options later, no doubt */
 356
 357
 358 /*
 359  * Ordering of RGB data in scanlines passed to or from the application.
 360  * If your application wants to deal with data in the order B,G,R, just
 361  * change these macros.  You can also deal with formats such as R,G,B,X
 362  * (one extra byte per pixel) by changing RGB_PIXELSIZE.  Note that changing
 363  * the offsets will also change the order in which colormap data is organized.
 364  * RESTRICTIONS:
 365  * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
 366  * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
 367  *    useful if you are using JPEG color spaces other than YCbCr or grayscale.
 368  * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
 369  *    is not 3 (they don't understand about dummy color components!).  So you
 370  *    can't use color quantization if you change that value.
 371  */
 372
 373 #define RGB_RED         0       /* Offset of Red in an RGB scanline element */
 374 #define RGB_GREEN       1       /* Offset of Green */
 375 #define RGB_BLUE        2       /* Offset of Blue */
 376 #define RGB_PIXELSIZE   3       /* JSAMPLEs per RGB scanline element */
 377
 378
 379 /* Definitions for speed-related optimizations. */
 380
 381
 382 /* If your compiler supports inline functions, define INLINE
 383  * as the inline keyword; otherwise define it as empty.
 384  */
 385
 386 /* Mozilla mods here: add more ways of defining INLINE */
 387
 388 #ifndef INLINE
 389 #ifdef __GNUC__                 /* for instance, GNU C knows about inline */
 390 #define INLINE __inline__
 391 #endif
 392 #if defined( __IBMC__ ) || defined (__IBMCPP__)
 393 #define INLINE _Inline
 394 #endif
 395 #ifndef INLINE
 396 #ifdef __cplusplus
 397 #define INLINE inline           /* a C++ compiler should have it too */
 398 #else
 399 #define INLINE                  /* default is to define it as empty */
 400 #endif
 401 #endif
 402 #endif
 403
 404
 405 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
 406  * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER
 407  * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.
 408  */
 409
 410 #ifndef MULTIPLIER
 411 #define MULTIPLIER  int16               /* type for fastest integer multiply */
 412 #endif
 413
 414
 415 /* FAST_FLOAT should be either float or double, whichever is done faster
 416  * by your compiler.  (Note that this type is only used in the floating point
 417  * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
 418  * Typically, float is faster in ANSI C compilers, while double is faster in
 419  * pre-ANSI compilers (because they insist on converting to double anyway).
 420  * The code below therefore chooses float if we have ANSI-style prototypes.
 421  */
 422
 423 #ifndef FAST_FLOAT
 424 #ifdef HAVE_PROTOTYPES
 425 #define FAST_FLOAT  float
 426 #else
 427 #define FAST_FLOAT  double
 428 #endif
 429 #endif
 430
 431 #endif /* JPEG_INTERNAL_OPTIONS */