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 #if BITS_IN_JSAMPLE == 12 00079 /* JSAMPLE should be the smallest type that will hold the values 0..4095. 00080 * On nearly all machines "short" will do nicely. 00081 */ 00082 00083 typedef short JSAMPLE; 00084 #define GETJSAMPLE(value) ((int) (value)) 00085 00086 #define MAXJSAMPLE 4095 00087 #define CENTERJSAMPLE 2048 00088 00089 #endif /* BITS_IN_JSAMPLE == 12 */ 00090 00091 00092 /* Representation of a DCT frequency coefficient. 00093 * This should be a signed value of at least 16 bits; "short" is usually OK. 00094 * Again, we allocate large arrays of these, but you can change to int 00095 * if you have memory to burn and "short" is really slow. 00096 */ 00097 00098 typedef short JCOEF; 00099 00100 00101 /* Compressed datastreams are represented as arrays of JOCTET. 00102 * These must be EXACTLY 8 bits wide, at least once they are written to 00103 * external storage. Note that when using the stdio data source/destination 00104 * managers, this is also the data type passed to fread/fwrite. 00105 */ 00106 00107 #ifdef HAVE_UNSIGNED_CHAR 00108 00109 typedef unsigned char JOCTET; 00110 #define GETJOCTET(value) (value) 00111 00112 #else /* not HAVE_UNSIGNED_CHAR */ 00113 00114 typedef char JOCTET; 00115 #ifdef CHAR_IS_UNSIGNED 00116 #define GETJOCTET(value) (value) 00117 #else 00118 #define GETJOCTET(value) ((value) & 0xFF) 00119 #endif /* CHAR_IS_UNSIGNED */ 00120 00121 #endif /* HAVE_UNSIGNED_CHAR */ 00122 00123 00124 /* These typedefs are used for various table entries and so forth. 00125 * They must be at least as wide as specified; but making them too big 00126 * won't cost a huge amount of memory, so we don't provide special 00127 * extraction code like we did for JSAMPLE. (In other words, these 00128 * typedefs live at a different point on the speed/space tradeoff curve.) 00129 */ 00130 00131 /* UINT8 must hold at least the values 0..255. */ 00132 00133 #ifdef HAVE_UNSIGNED_CHAR 00134 typedef unsigned char UINT8; 00135 #else /* not HAVE_UNSIGNED_CHAR */ 00136 #ifdef CHAR_IS_UNSIGNED 00137 typedef char UINT8; 00138 #else /* not CHAR_IS_UNSIGNED */ 00139 typedef short UINT8; 00140 #endif /* CHAR_IS_UNSIGNED */ 00141 #endif /* HAVE_UNSIGNED_CHAR */ 00142 00143 /* UINT16 must hold at least the values 0..65535. */ 00144 00145 #ifdef HAVE_UNSIGNED_SHORT 00146 typedef unsigned short UINT16; 00147 #else /* not HAVE_UNSIGNED_SHORT */ 00148 typedef unsigned int UINT16; 00149 #endif /* HAVE_UNSIGNED_SHORT */ 00150 /* INT16 must hold at least the values -32768..32767. */ 00151 00152 #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ 00153 typedef short INT16; 00154 #endif 00155 00156 /* INT32 must hold at least signed 32-bit values. */ 00157 00158 #if !defined( XMD_H ) && !defined( _BASETSD_H_ ) 00159 /* X11/xmd.h and MS VC++ 6.0 correctly define INT32 */ 00160 typedef long INT32; 00161 #endif 00162 00163 /* Datatype used for image dimensions. The JPEG standard only supports 00164 * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore 00165 * "unsigned int" is sufficient on all machines. However, if you need to 00166 * handle larger images and you don't mind deviating from the spec, you 00167 * can change this datatype. 00168 */ 00169 00170 typedef unsigned int JDIMENSION; 00171 00172 #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ 00173 00174 00175 /* These macros are used in all function definitions and extern declarations. 00176 * You could modify them if you need to change function linkage conventions; 00177 * in particular, you'll need to do that to make the library a Windows DLL. 00178 * Another application is to make all functions global for use with debuggers 00179 * or code profilers that require it. 00180 */ 00181 00182 /* a function called through method pointers: */ 00183 #define METHODDEF(type) static type 00184 /* a function used only in its module: */ 00185 #define LOCAL(type) static type 00186 /* a function referenced thru EXTERNs: */ 00187 #define GLOBAL(type) type 00188 /* a reference to a GLOBAL function: */ 00189 #define EXTERN(type) extern type 00190 00191 00192 /* This macro is used to declare a "method", that is, a function pointer. 00193 * We want to supply prototype parameters if the compiler can cope. 00194 * Note that the arglist parameter must be parenthesized! 00195 * Again, you can customize this if you need special linkage keywords. 00196 */ 00197 00198 #ifdef HAVE_PROTOTYPES 00199 #define JMETHOD(type,methodname,arglist) type (*methodname) arglist 00200 #else 00201 #define JMETHOD(type,methodname,arglist) type (*methodname) () 00202 #endif 00203 00204 00205 /* Here is the pseudo-keyword for declaring pointers that must be "far" 00206 * on 80x86 machines. Most of the specialized coding for 80x86 is handled 00207 * by just saying "FAR *" where such a pointer is needed. In a few places 00208 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. 00209 */ 00210 /* Change Ulrich von Zadow 9/96: 00211 * The WIN32 headers define FAR as empty already. To prevent warnings, 00212 * we shouldn't do it here. 00213 */ 00214 #ifdef NEED_FAR_POINTERS 00215 #define FAR far 00216 #else 00217 #ifndef FAR 00218 #define FAR 00219 #endif 00220 #endif 00221 00222 /* 00223 * On a few systems, type boolean and/or its values false, true may appear 00224 * in standard header files. Or you may have conflicts with application- 00225 * specific header files that you want to include together with these files. 00226 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. 00227 */ 00228 00229 #ifndef HAVE_BOOLEAN 00230 #ifndef __RPCNDR_H__ /* don't conflict if rpcndr.h already read */ 00231 typedef unsigned char boolean; 00232 #endif 00233 #endif 00234 #ifndef FALSE /* in case these macros already exist */ 00235 #define FALSE 0 /* values of boolean */ 00236 #endif 00237 #ifndef TRUE 00238 #define TRUE 1 00239 #endif 00240 00241 00242 /* 00243 * The remaining options affect code selection within the JPEG library, 00244 * but they don't need to be visible to most applications using the library. 00245 * To minimize application namespace pollution, the symbols won't be 00246 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. 00247 */ 00248 00249 #ifdef JPEG_INTERNALS 00250 #define JPEG_INTERNAL_OPTIONS 00251 #endif 00252 00253 #ifdef JPEG_INTERNAL_OPTIONS 00254 00255 00256 /* 00257 * These defines indicate whether to include various optional functions. 00258 * Undefining some of these symbols will produce a smaller but less capable 00259 * library. Note that you can leave certain source files out of the 00260 * compilation/linking process if you've #undef'd the corresponding symbols. 00261 * (You may HAVE to do that if your compiler doesn't like null source files.) 00262 */ 00263 00264 /* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */ 00265 00266 /* Capability options common to encoder and decoder: */ 00267 00268 #undef DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ 00269 #undef DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ 00270 #define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ 00271 00272 /* Encoder capability options: */ 00273 00274 #undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 00275 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 00276 #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 00277 #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ 00278 /* Note: if you selected 12-bit data precision, it is dangerous to turn off 00279 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit 00280 * precision, so jchuff.c normally uses entropy optimization to compute 00281 * usable tables for higher precision. If you don't want to do optimization, 00282 * you'll have to supply different default Huffman tables. 00283 * The exact same statements apply for progressive JPEG: the default tables 00284 * don't work for progressive mode. (This may get fixed, however.) 00285 */ 00286 #undef INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ 00287 00288 /* Decoder capability options: */ 00289 00290 #undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 00291 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 00292 #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 00293 #undef BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ 00294 #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ 00295 #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ 00296 #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ 00297 #define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ 00298 #define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ 00299 #define SAVE_MARKERS_SUPPORTED 00300 00301 /* more capability options later, no doubt */ 00302 00303 00304 /* 00305 * Ordering of RGB data in scanlines passed to or from the application. 00306 * If your application wants to deal with data in the order B,G,R, just 00307 * change these macros. You can also deal with formats such as R,G,B,X 00308 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing 00309 * the offsets will also change the order in which colormap data is organized. 00310 * RESTRICTIONS: 00311 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. 00312 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not 00313 * useful if you are using JPEG color spaces other than YCbCr or grayscale. 00314 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE 00315 * is not 3 (they don't understand about dummy color components!). So you 00316 * can't use color quantization if you change that value. 00317 */ 00318 00319 #define RGB_RED 2 /* Offset of Red in an RGB scanline element */ 00320 #define RGB_GREEN 1 /* Offset of Green */ 00321 #define RGB_BLUE 0 /* Offset of Blue */ 00322 #define RGB_PIXELSIZE 4 /* JSAMPLEs per RGB scanline element */ 00323 00324 00325 /* Definitions for speed-related optimizations. */ 00326 00327 00328 /* If your compiler supports inline functions, define INLINE 00329 * as the inline keyword; otherwise define it as empty. 00330 */ 00331 00332 #ifndef INLINE 00333 #ifdef __GNUC__ /* for instance, GNU C knows about inline */ 00334 #define INLINE __inline__ 00335 #endif 00336 #ifndef INLINE 00337 #define INLINE /* default is to define it as empty */ 00338 #endif 00339 #endif 00340 00341 00342 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying 00343 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER 00344 * as short on such a machine. MULTIPLIER must be at least 16 bits wide. 00345 */ 00346 00347 #ifndef MULTIPLIER 00348 #define MULTIPLIER int /* type for fastest integer multiply */ 00349 #endif 00350 00351 00352 /* FAST_FLOAT should be either float or double, whichever is done faster 00353 * by your compiler. (Note that this type is only used in the floating point 00354 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) 00355 * Typically, float is faster in ANSI C compilers, while double is faster in 00356 * pre-ANSI compilers (because they insist on converting to double anyway). 00357 * The code below therefore chooses float if we have ANSI-style prototypes. 00358 */ 00359 /* Change Ulrich von Zadow 9/96: 00360 * Double is the native pentium floating point type, so it's 00361 * definitely the fastest in this configuration. 00362 */ 00363 #ifndef FAST_FLOAT 00364 #ifdef HAVE_PROTOTYPES 00365 #ifdef WIN32 00366 #define FAST_FLOAT double 00367 #else 00368 #define FAST_FLOAT float 00369 #endif 00370 #else 00371 #define FAST_FLOAT double 00372 #endif 00373 #endif 00374 00375 #endif /* JPEG_INTERNAL_OPTIONS */