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 * Define ANDROID_RGB to enable specific optimizations for Android 15 * JCS_RGBA_8888 support 16 * JCS_RGB_565 support 17 * 18 */ 19 20 #define ANDROID_RGB 21 22 #ifdef ANDROID_RGB 23 #define PACK_SHORT_565(r,g,b) ((((r)<<8)&0xf800)|(((g)<<3)&0x7E0)|((b)>>3)) 24 #define PACK_TWO_PIXELS(l,r) ((r<<16) | l) 25 #define PACK_NEED_ALIGNMENT(ptr) (((int)(ptr))&3) 26 #define WRITE_TWO_PIXELS(addr, pixels) do { \ 27 ((INT16*)(addr))[0] = (pixels); \ 28 ((INT16*)(addr))[1] = (pixels)>>16; \ 29 } while(0) 30 #define WRITE_TWO_ALIGNED_PIXELS(addr, pixels) ((*(INT32*)(addr)) = pixels) 31 #define DITHER_565_R(r, dither) ((r) + ((dither)&0xFF)) 32 #define DITHER_565_G(g, dither) ((g) + (((dither)&0xFF)>>1)) 33 #define DITHER_565_B(b, dither) ((b) + ((dither)&0xFF)) 34 #endif 35 36 /* 37 * Define BITS_IN_JSAMPLE as either 38 * 8 for 8-bit sample values (the usual setting) 39 * 12 for 12-bit sample values 40 * Only 8 and 12 are legal data precisions for lossy JPEG according to the 41 * JPEG standard, and the IJG code does not support anything else! 42 * We do not support run-time selection of data precision, sorry. 43 */ 44 45 #define BITS_IN_JSAMPLE 8 /* use 8 or 12 */ 46 47 48 /* 49 * Maximum number of components (color channels) allowed in JPEG image. 50 * To meet the letter of the JPEG spec, set this to 255. However, darn 51 * few applications need more than 4 channels (maybe 5 for CMYK + alpha 52 * mask). We recommend 10 as a reasonable compromise; use 4 if you are 53 * really short on memory. (Each allowed component costs a hundred or so 54 * bytes of storage, whether actually used in an image or not.) 55 */ 56 57 #define MAX_COMPONENTS 10 /* maximum number of image components */ 58 59 60 /* 61 * Basic data types. 62 * You may need to change these if you have a machine with unusual data 63 * type sizes; for example, "char" not 8 bits, "short" not 16 bits, 64 * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, 65 * but it had better be at least 16. 66 */ 67 68 /* Representation of a single sample (pixel element value). 69 * We frequently allocate large arrays of these, so it's important to keep 70 * them small. But if you have memory to burn and access to char or short 71 * arrays is very slow on your hardware, you might want to change these. 72 */ 73 74 #if BITS_IN_JSAMPLE == 8 75 /* JSAMPLE should be the smallest type that will hold the values 0..255. 76 * You can use a signed char by having GETJSAMPLE mask it with 0xFF. 77 */ 78 79 #ifdef HAVE_UNSIGNED_CHAR 80 81 typedef unsigned char JSAMPLE; 82 #define GETJSAMPLE(value) ((int) (value)) 83 84 #else /* not HAVE_UNSIGNED_CHAR */ 85 86 typedef char JSAMPLE; 87 #ifdef CHAR_IS_UNSIGNED 88 #define GETJSAMPLE(value) ((int) (value)) 89 #else 90 #define GETJSAMPLE(value) ((int) (value) & 0xFF) 91 #endif /* CHAR_IS_UNSIGNED */ 92 93 #endif /* HAVE_UNSIGNED_CHAR */ 94 95 #define MAXJSAMPLE 255 96 #define CENTERJSAMPLE 128 97 98 #endif /* BITS_IN_JSAMPLE == 8 */ 99 100 101 #if BITS_IN_JSAMPLE == 12 102 /* JSAMPLE should be the smallest type that will hold the values 0..4095. 103 * On nearly all machines "short" will do nicely. 104 */ 105 106 typedef short JSAMPLE; 107 #define GETJSAMPLE(value) ((int) (value)) 108 109 #define MAXJSAMPLE 4095 110 #define CENTERJSAMPLE 2048 111 112 #endif /* BITS_IN_JSAMPLE == 12 */ 113 114 115 /* Representation of a DCT frequency coefficient. 116 * This should be a signed value of at least 16 bits; "short" is usually OK. 117 * Again, we allocate large arrays of these, but you can change to int 118 * if you have memory to burn and "short" is really slow. 119 */ 120 121 typedef short JCOEF; 122 123 124 /* Compressed datastreams are represented as arrays of JOCTET. 125 * These must be EXACTLY 8 bits wide, at least once they are written to 126 * external storage. Note that when using the stdio data source/destination 127 * managers, this is also the data type passed to fread/fwrite. 128 */ 129 130 #ifdef HAVE_UNSIGNED_CHAR 131 132 typedef unsigned char JOCTET; 133 #define GETJOCTET(value) (value) 134 135 #else /* not HAVE_UNSIGNED_CHAR */ 136 137 typedef char JOCTET; 138 #ifdef CHAR_IS_UNSIGNED 139 #define GETJOCTET(value) (value) 140 #else 141 #define GETJOCTET(value) ((value) & 0xFF) 142 #endif /* CHAR_IS_UNSIGNED */ 143 144 #endif /* HAVE_UNSIGNED_CHAR */ 145 146 147 /* These typedefs are used for various table entries and so forth. 148 * They must be at least as wide as specified; but making them too big 149 * won't cost a huge amount of memory, so we don't provide special 150 * extraction code like we did for JSAMPLE. (In other words, these 151 * typedefs live at a different point on the speed/space tradeoff curve.) 152 */ 153 154 /* UINT8 must hold at least the values 0..255. */ 155 156 #ifdef HAVE_UNSIGNED_CHAR 157 typedef unsigned char UINT8; 158 #else /* not HAVE_UNSIGNED_CHAR */ 159 #ifdef CHAR_IS_UNSIGNED 160 typedef char UINT8; 161 #else /* not CHAR_IS_UNSIGNED */ 162 typedef short UINT8; 163 #endif /* CHAR_IS_UNSIGNED */ 164 #endif /* HAVE_UNSIGNED_CHAR */ 165 166 /* UINT16 must hold at least the values 0..65535. */ 167 168 #ifdef HAVE_UNSIGNED_SHORT 169 typedef unsigned short UINT16; 170 #else /* not HAVE_UNSIGNED_SHORT */ 171 typedef unsigned int UINT16; 172 #endif /* HAVE_UNSIGNED_SHORT */ 173 174 /* INT16 must hold at least the values -32768..32767. */ 175 176 #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ 177 typedef short INT16; 178 #endif 179 180 /* INT32 must hold at least signed 32-bit values. */ 181 182 #ifndef XMD_H /* X11/xmd.h correctly defines INT32 */ 183 typedef long INT32; 184 #endif 185 186 /* Datatype used for image dimensions. The JPEG standard only supports 187 * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore 188 * "unsigned int" is sufficient on all machines. However, if you need to 189 * handle larger images and you don't mind deviating from the spec, you 190 * can change this datatype. 191 */ 192 193 typedef unsigned int JDIMENSION; 194 195 #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ 196 197 198 /* These macros are used in all function definitions and extern declarations. 199 * You could modify them if you need to change function linkage conventions; 200 * in particular, you'll need to do that to make the library a Windows DLL. 201 * Another application is to make all functions global for use with debuggers 202 * or code profilers that require it. 203 */ 204 205 /* a function called through method pointers: */ 206 #define METHODDEF(type) static type 207 /* a function used only in its module: */ 208 #define LOCAL(type) static type 209 /* a function referenced thru EXTERNs: */ 210 #define GLOBAL(type) type 211 /* a reference to a GLOBAL function: */ 212 #define EXTERN(type) extern type 213 214 215 /* This macro is used to declare a "method", that is, a function pointer. 216 * We want to supply prototype parameters if the compiler can cope. 217 * Note that the arglist parameter must be parenthesized! 218 * Again, you can customize this if you need special linkage keywords. 219 */ 220 221 #ifdef HAVE_PROTOTYPES 222 #define JMETHOD(type,methodname,arglist) type (*methodname) arglist 223 #else 224 #define JMETHOD(type,methodname,arglist) type (*methodname) () 225 #endif 226 227 228 /* Here is the pseudo-keyword for declaring pointers that must be "far" 229 * on 80x86 machines. Most of the specialized coding for 80x86 is handled 230 * by just saying "FAR *" where such a pointer is needed. In a few places 231 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. 232 */ 233 234 #ifdef NEED_FAR_POINTERS 235 #define FAR far 236 #else 237 #define FAR 238 #endif 239 240 241 /* 242 * On a few systems, type boolean and/or its values FALSE, TRUE may appear 243 * in standard header files. Or you may have conflicts with application- 244 * specific header files that you want to include together with these files. 245 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. 246 */ 247 248 #ifndef HAVE_BOOLEAN 249 typedef int boolean; 250 #endif 251 #ifndef FALSE /* in case these macros already exist */ 252 #define FALSE 0 /* values of boolean */ 253 #endif 254 #ifndef TRUE 255 #define TRUE 1 256 #endif 257 258 259 /* 260 * The remaining options affect code selection within the JPEG library, 261 * but they don't need to be visible to most applications using the library. 262 * To minimize application namespace pollution, the symbols won't be 263 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. 264 */ 265 266 #ifdef JPEG_INTERNALS 267 #define JPEG_INTERNAL_OPTIONS 268 #endif 269 270 #ifdef JPEG_INTERNAL_OPTIONS 271 272 273 /* 274 * These defines indicate whether to include various optional functions. 275 * Undefining some of these symbols will produce a smaller but less capable 276 * library. Note that you can leave certain source files out of the 277 * compilation/linking process if you've #undef'd the corresponding symbols. 278 * (You may HAVE to do that if your compiler doesn't like null source files.) 279 */ 280 281 /* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */ 282 283 /* Capability options common to encoder and decoder: */ 284 285 #define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ 286 #define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ 287 #define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ 288 289 /* Encoder capability options: */ 290 291 #undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 292 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 293 #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 294 #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ 295 /* Note: if you selected 12-bit data precision, it is dangerous to turn off 296 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit 297 * precision, so jchuff.c normally uses entropy optimization to compute 298 * usable tables for higher precision. If you don't want to do optimization, 299 * you'll have to supply different default Huffman tables. 300 * The exact same statements apply for progressive JPEG: the default tables 301 * don't work for progressive mode. (This may get fixed, however.) 302 */ 303 #define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ 304 305 /* Decoder capability options: */ 306 307 #undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ 308 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ 309 #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ 310 #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ 311 #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ 312 #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ 313 #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ 314 #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ 315 #define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ 316 #define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ 317 318 /* more capability options later, no doubt */ 319 320 321 /* 322 * Ordering of RGB data in scanlines passed to or from the application. 323 * If your application wants to deal with data in the order B,G,R, just 324 * change these macros. You can also deal with formats such as R,G,B,X 325 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing 326 * the offsets will also change the order in which colormap data is organized. 327 * RESTRICTIONS: 328 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. 329 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not 330 * useful if you are using JPEG color spaces other than YCbCr or grayscale. 331 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE 332 * is not 3 (they don't understand about dummy color components!). So you 333 * can't use color quantization if you change that value. 334 */ 335 336 #define RGB_RED 0 /* Offset of Red in an RGB scanline element */ 337 #define RGB_GREEN 1 /* Offset of Green */ 338 #define RGB_BLUE 2 /* Offset of Blue */ 339 #ifdef ANDROID_RGB 340 #define RGB_ALPHA 3 /* Offset of Alpha */ 341 #endif 342 #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ 343 344 /* Definitions for speed-related optimizations. */ 345 346 347 /* If your compiler supports inline functions, define INLINE 348 * as the inline keyword; otherwise define it as empty. 349 */ 350 351 #ifndef INLINE 352 #ifdef __GNUC__ /* for instance, GNU C knows about inline */ 353 #define INLINE __inline__ 354 #endif 355 #ifndef INLINE 356 #define INLINE /* default is to define it as empty */ 357 #endif 358 #endif 359 360 361 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying 362 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER 363 * as short on such a machine. MULTIPLIER must be at least 16 bits wide. 364 */ 365 366 #ifndef MULTIPLIER 367 #define MULTIPLIER int /* type for fastest integer multiply */ 368 #endif 369 370 371 /* FAST_FLOAT should be either float or double, whichever is done faster 372 * by your compiler. (Note that this type is only used in the floating point 373 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) 374 * Typically, float is faster in ANSI C compilers, while double is faster in 375 * pre-ANSI compilers (because they insist on converting to double anyway). 376 * The code below therefore chooses float if we have ANSI-style prototypes. 377 */ 378 379 #ifndef FAST_FLOAT 380 #ifdef HAVE_PROTOTYPES 381 #define FAST_FLOAT float 382 #else 383 #define FAST_FLOAT double 384 #endif 385 #endif 386 387 #endif /* JPEG_INTERNAL_OPTIONS */ 388