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plt-scheme  4.2.1
jmorecfg.h
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00001 /*
00002  * jmorecfg.h
00003  *
00004  * Copyright (C) 1991-1997, Thomas G. Lane.
00005  * This file is part of the Independent JPEG Group's software.
00006  * For conditions of distribution and use, see the accompanying README file.
00007  *
00008  * This file contains additional configuration options that customize the
00009  * JPEG software for special applications or support machine-dependent
00010  * optimizations.  Most users will not need to touch this file.
00011  */
00012 
00013 
00014 /*
00015  * Define BITS_IN_JSAMPLE as either
00016  *   8   for 8-bit sample values (the usual setting)
00017  *   12  for 12-bit sample values
00018  * Only 8 and 12 are legal data precisions for lossy JPEG according to the
00019  * JPEG standard, and the IJG code does not support anything else!
00020  * We do not support run-time selection of data precision, sorry.
00021  */
00022 
00023 #define BITS_IN_JSAMPLE  8  /* use 8 or 12 */
00024 
00025 
00026 /*
00027  * Maximum number of components (color channels) allowed in JPEG image.
00028  * To meet the letter of the JPEG spec, set this to 255.  However, darn
00029  * few applications need more than 4 channels (maybe 5 for CMYK + alpha
00030  * mask).  We recommend 10 as a reasonable compromise; use 4 if you are
00031  * really short on memory.  (Each allowed component costs a hundred or so
00032  * bytes of storage, whether actually used in an image or not.)
00033  */
00034 
00035 #define MAX_COMPONENTS  10  /* maximum number of image components */
00036 
00037 
00038 /*
00039  * Basic data types.
00040  * You may need to change these if you have a machine with unusual data
00041  * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
00042  * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits,
00043  * but it had better be at least 16.
00044  */
00045 
00046 /* Representation of a single sample (pixel element value).
00047  * We frequently allocate large arrays of these, so it's important to keep
00048  * them small.  But if you have memory to burn and access to char or short
00049  * arrays is very slow on your hardware, you might want to change these.
00050  */
00051 
00052 #if BITS_IN_JSAMPLE == 8
00053 /* JSAMPLE should be the smallest type that will hold the values 0..255.
00054  * You can use a signed char by having GETJSAMPLE mask it with 0xFF.
00055  */
00056 
00057 #ifdef HAVE_UNSIGNED_CHAR
00058 
00059 typedef unsigned char JSAMPLE;
00060 #define GETJSAMPLE(value)  ((int) (value))
00061 
00062 #else /* not HAVE_UNSIGNED_CHAR */
00063 
00064 typedef char JSAMPLE;
00065 #ifdef CHAR_IS_UNSIGNED
00066 #define GETJSAMPLE(value)  ((int) (value))
00067 #else
00068 #define GETJSAMPLE(value)  ((int) (value) & 0xFF)
00069 #endif /* CHAR_IS_UNSIGNED */
00070 
00071 #endif /* HAVE_UNSIGNED_CHAR */
00072 
00073 #define MAXJSAMPLE   255
00074 #define CENTERJSAMPLE       128
00075 
00076 #endif /* BITS_IN_JSAMPLE == 8 */
00077 
00078 
00079 #if BITS_IN_JSAMPLE == 12
00080 /* JSAMPLE should be the smallest type that will hold the values 0..4095.
00081  * On nearly all machines "short" will do nicely.
00082  */
00083 
00084 typedef short JSAMPLE;
00085 #define GETJSAMPLE(value)  ((int) (value))
00086 
00087 #define MAXJSAMPLE   4095
00088 #define CENTERJSAMPLE       2048
00089 
00090 #endif /* BITS_IN_JSAMPLE == 12 */
00091 
00092 
00093 /* Representation of a DCT frequency coefficient.
00094  * This should be a signed value of at least 16 bits; "short" is usually OK.
00095  * Again, we allocate large arrays of these, but you can change to int
00096  * if you have memory to burn and "short" is really slow.
00097  */
00098 
00099 typedef short JCOEF;
00100 
00101 
00102 /* Compressed datastreams are represented as arrays of JOCTET.
00103  * These must be EXACTLY 8 bits wide, at least once they are written to
00104  * external storage.  Note that when using the stdio data source/destination
00105  * managers, this is also the data type passed to fread/fwrite.
00106  */
00107 
00108 #ifdef HAVE_UNSIGNED_CHAR
00109 
00110 typedef unsigned char JOCTET;
00111 #define GETJOCTET(value)  (value)
00112 
00113 #else /* not HAVE_UNSIGNED_CHAR */
00114 
00115 typedef char JOCTET;
00116 #ifdef CHAR_IS_UNSIGNED
00117 #define GETJOCTET(value)  (value)
00118 #else
00119 #define GETJOCTET(value)  ((value) & 0xFF)
00120 #endif /* CHAR_IS_UNSIGNED */
00121 
00122 #endif /* HAVE_UNSIGNED_CHAR */
00123 
00124 
00125 /* These typedefs are used for various table entries and so forth.
00126  * They must be at least as wide as specified; but making them too big
00127  * won't cost a huge amount of memory, so we don't provide special
00128  * extraction code like we did for JSAMPLE.  (In other words, these
00129  * typedefs live at a different point on the speed/space tradeoff curve.)
00130  */
00131 
00132 /* UINT8 must hold at least the values 0..255. */
00133 
00134 #ifdef HAVE_UNSIGNED_CHAR
00135 typedef unsigned char UINT8;
00136 #else /* not HAVE_UNSIGNED_CHAR */
00137 #ifdef CHAR_IS_UNSIGNED
00138 typedef char UINT8;
00139 #else /* not CHAR_IS_UNSIGNED */
00140 typedef short UINT8;
00141 #endif /* CHAR_IS_UNSIGNED */
00142 #endif /* HAVE_UNSIGNED_CHAR */
00143 
00144 /* UINT16 must hold at least the values 0..65535. */
00145 
00146 #ifdef HAVE_UNSIGNED_SHORT
00147 typedef unsigned short UINT16;
00148 #else /* not HAVE_UNSIGNED_SHORT */
00149 typedef unsigned int UINT16;
00150 #endif /* HAVE_UNSIGNED_SHORT */
00151 
00152 /* INT16 must hold at least the values -32768..32767. */
00153 
00154 #ifndef XMD_H               /* X11/xmd.h correctly defines INT16 */
00155 typedef short INT16;
00156 #endif
00157 
00158 /* INT32 must hold at least signed 32-bit values. */
00159 
00160 #ifndef XMD_H               /* X11/xmd.h correctly defines INT32 */
00161 # ifndef _BASETSD_H_    /* Windows header defined INT32 */
00162 typedef long INT32;
00163 # endif
00164 #endif
00165 
00166 /* Datatype used for image dimensions.  The JPEG standard only supports
00167  * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore
00168  * "unsigned int" is sufficient on all machines.  However, if you need to
00169  * handle larger images and you don't mind deviating from the spec, you
00170  * can change this datatype.
00171  */
00172 
00173 typedef unsigned int JDIMENSION;
00174 
00175 #define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */
00176 
00177 
00178 /* These macros are used in all function definitions and extern declarations.
00179  * You could modify them if you need to change function linkage conventions;
00180  * in particular, you'll need to do that to make the library a Windows DLL.
00181  * Another application is to make all functions global for use with debuggers
00182  * or code profilers that require it.
00183  */
00184 
00185 /* a function called through method pointers: */
00186 #define METHODDEF(type)            static type
00187 /* a function used only in its module: */
00188 #define LOCAL(type)         static type
00189 /* a function referenced thru EXTERNs: */
00190 #define GLOBAL(type)        type
00191 /* a reference to a GLOBAL function: */
00192 #define EXTERN(type)        extern type
00193 
00194 
00195 /* This macro is used to declare a "method", that is, a function pointer.
00196  * We want to supply prototype parameters if the compiler can cope.
00197  * Note that the arglist parameter must be parenthesized!
00198  * Again, you can customize this if you need special linkage keywords.
00199  */
00200 
00201 #ifdef HAVE_PROTOTYPES
00202 #define JMETHOD(type,methodname,arglist)  type (*methodname) arglist
00203 #else
00204 #define JMETHOD(type,methodname,arglist)  type (*methodname) ()
00205 #endif
00206 
00207 
00208 /* Here is the pseudo-keyword for declaring pointers that must be "far"
00209  * on 80x86 machines.  Most of the specialized coding for 80x86 is handled
00210  * by just saying "FAR *" where such a pointer is needed.  In a few places
00211  * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
00212  */
00213 
00214 #ifdef NEED_FAR_POINTERS
00215 #define FAR  far
00216 #else
00217 #define FAR
00218 #endif
00219 
00220 
00221 /*
00222  * On a few systems, type boolean and/or its values FALSE, TRUE may appear
00223  * in standard header files.  Or you may have conflicts with application-
00224  * specific header files that you want to include together with these files.
00225  * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
00226  */
00227 
00228 #ifndef HAVE_BOOLEAN
00229 typedef int boolean;
00230 #endif
00231 #ifndef FALSE               /* in case these macros already exist */
00232 #define FALSE 0             /* values of boolean */
00233 #endif
00234 #ifndef TRUE
00235 #define TRUE  1
00236 #endif
00237 
00238 
00239 /*
00240  * The remaining options affect code selection within the JPEG library,
00241  * but they don't need to be visible to most applications using the library.
00242  * To minimize application namespace pollution, the symbols won't be
00243  * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
00244  */
00245 
00246 #ifdef JPEG_INTERNALS
00247 #define JPEG_INTERNAL_OPTIONS
00248 #endif
00249 
00250 #ifdef JPEG_INTERNAL_OPTIONS
00251 
00252 
00253 /*
00254  * These defines indicate whether to include various optional functions.
00255  * Undefining some of these symbols will produce a smaller but less capable
00256  * library.  Note that you can leave certain source files out of the
00257  * compilation/linking process if you've #undef'd the corresponding symbols.
00258  * (You may HAVE to do that if your compiler doesn't like null source files.)
00259  */
00260 
00261 /* Arithmetic coding is unsupported for legal reasons.  Complaints to IBM. */
00262 
00263 /* Capability options common to encoder and decoder: */
00264 
00265 #define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */
00266 #define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */
00267 #define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */
00268 
00269 /* Encoder capability options: */
00270 
00271 #undef  C_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
00272 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
00273 #define C_PROGRESSIVE_SUPPORTED        /* Progressive JPEG? (Requires MULTISCAN)*/
00274 #define ENTROPY_OPT_SUPPORTED          /* Optimization of entropy coding parms? */
00275 /* Note: if you selected 12-bit data precision, it is dangerous to turn off
00276  * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit
00277  * precision, so jchuff.c normally uses entropy optimization to compute
00278  * usable tables for higher precision.  If you don't want to do optimization,
00279  * you'll have to supply different default Huffman tables.
00280  * The exact same statements apply for progressive JPEG: the default tables
00281  * don't work for progressive mode.  (This may get fixed, however.)
00282  */
00283 #define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */
00284 
00285 /* Decoder capability options: */
00286 
00287 #undef  D_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
00288 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
00289 #define D_PROGRESSIVE_SUPPORTED        /* Progressive JPEG? (Requires MULTISCAN)*/
00290 #define SAVE_MARKERS_SUPPORTED         /* jpeg_save_markers() needed? */
00291 #define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
00292 #define IDCT_SCALING_SUPPORTED         /* Output rescaling via IDCT? */
00293 #undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
00294 #define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
00295 #define QUANT_1PASS_SUPPORTED          /* 1-pass color quantization? */
00296 #define QUANT_2PASS_SUPPORTED          /* 2-pass color quantization? */
00297 
00298 /* more capability options later, no doubt */
00299 
00300 
00301 /*
00302  * Ordering of RGB data in scanlines passed to or from the application.
00303  * If your application wants to deal with data in the order B,G,R, just
00304  * change these macros.  You can also deal with formats such as R,G,B,X
00305  * (one extra byte per pixel) by changing RGB_PIXELSIZE.  Note that changing
00306  * the offsets will also change the order in which colormap data is organized.
00307  * RESTRICTIONS:
00308  * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
00309  * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
00310  *    useful if you are using JPEG color spaces other than YCbCr or grayscale.
00311  * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
00312  *    is not 3 (they don't understand about dummy color components!).  So you
00313  *    can't use color quantization if you change that value.
00314  */
00315 
00316 #define RGB_RED             0      /* Offset of Red in an RGB scanline element */
00317 #define RGB_GREEN    1      /* Offset of Green */
00318 #define RGB_BLUE     2      /* Offset of Blue */
00319 #define RGB_PIXELSIZE       3      /* JSAMPLEs per RGB scanline element */
00320 
00321 
00322 /* Definitions for speed-related optimizations. */
00323 
00324 
00325 /* If your compiler supports inline functions, define INLINE
00326  * as the inline keyword; otherwise define it as empty.
00327  */
00328 
00329 #ifndef INLINE
00330 #ifdef __GNUC__                    /* for instance, GNU C knows about inline */
00331 #define INLINE __inline__
00332 #endif
00333 #ifndef INLINE
00334 #define INLINE                     /* default is to define it as empty */
00335 #endif
00336 #endif
00337 
00338 
00339 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
00340  * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER
00341  * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.
00342  */
00343 
00344 #ifndef MULTIPLIER
00345 #define MULTIPLIER  int            /* type for fastest integer multiply */
00346 #endif
00347 
00348 
00349 /* FAST_FLOAT should be either float or double, whichever is done faster
00350  * by your compiler.  (Note that this type is only used in the floating point
00351  * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
00352  * Typically, float is faster in ANSI C compilers, while double is faster in
00353  * pre-ANSI compilers (because they insist on converting to double anyway).
00354  * The code below therefore chooses float if we have ANSI-style prototypes.
00355  */
00356 
00357 #ifndef FAST_FLOAT
00358 #ifdef HAVE_PROTOTYPES
00359 #define FAST_FLOAT  float
00360 #else
00361 #define FAST_FLOAT  double
00362 #endif
00363 #endif
00364 
00365 #endif /* JPEG_INTERNAL_OPTIONS */