media/libjpeg/jmorecfg.h

   1 /*
   2  * jmorecfg.h
   3  *
   4  * This file was part of the Independent JPEG Group's software:
   5  * Copyright (C) 1991-1997, Thomas G. Lane.
   6  * Modifications:
   7  * Copyright (C) 2009, 2011, D. R. Commander.
   8  * For conditions of distribution and use, see the accompanying README file.
   9  *
  10  * This file contains additional configuration options that customize the
  11  * JPEG software for special applications or support machine-dependent
  12  * optimizations.  Most users will not need to touch this file.
  13  */
  14
  15 #include <stdint.h>
  16
  17 /*
  18  * Define BITS_IN_JSAMPLE as either
  19  *   8   for 8-bit sample values (the usual setting)
  20  *   12  for 12-bit sample values
  21  * Only 8 and 12 are legal data precisions for lossy JPEG according to the
  22  * JPEG standard, and the IJG code does not support anything else!
  23  * We do not support run-time selection of data precision, sorry.
  24  */
  25
  26 #define BITS_IN_JSAMPLE  8      /* use 8 or 12 */
  27
  28
  29 /*
  30  * Maximum number of components (color channels) allowed in JPEG image.
  31  * To meet the letter of the JPEG spec, set this to 255.  However, darn
  32  * few applications need more than 4 channels (maybe 5 for CMYK + alpha
  33  * mask).  We recommend 10 as a reasonable compromise; use 4 if you are
  34  * really short on memory.  (Each allowed component costs a hundred or so
  35  * bytes of storage, whether actually used in an image or not.)
  36  */
  37
  38 #define MAX_COMPONENTS  10      /* maximum number of image components */
  39
  40
  41 /*
  42  * Basic data types.
  43  * You may need to change these if you have a machine with unusual data
  44  * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
  45  * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits,
  46  * but it had better be at least 16.
  47  */
  48
  49 /* Representation of a single sample (pixel element value).
  50  * We frequently allocate large arrays of these, so it's important to keep
  51  * them small.  But if you have memory to burn and access to char or short
  52  * arrays is very slow on your hardware, you might want to change these.
  53  */
  54
  55 #if BITS_IN_JSAMPLE == 8
  56 /* JSAMPLE should be the smallest type that will hold the values 0..255.
  57  * You can use a signed char by having GETJSAMPLE mask it with 0xFF.
  58  */
  59
  60 #ifdef HAVE_UNSIGNED_CHAR
  61
  62 typedef unsigned char JSAMPLE;
  63 #define GETJSAMPLE(value)  ((int) (value))
  64
  65 #else /* not HAVE_UNSIGNED_CHAR */
  66
  67 typedef char JSAMPLE;
  68 #ifdef __CHAR_UNSIGNED__
  69 #define GETJSAMPLE(value)  ((int) (value))
  70 #else
  71 #define GETJSAMPLE(value)  ((int) (value) & 0xFF)
  72 #endif /* __CHAR_UNSIGNED__ */
  73
  74 #endif /* HAVE_UNSIGNED_CHAR */
  75
  76 #define MAXJSAMPLE      255
  77 #define CENTERJSAMPLE   128
  78
  79 #endif /* BITS_IN_JSAMPLE == 8 */
  80
  81
  82 #if BITS_IN_JSAMPLE == 12
  83 /* JSAMPLE should be the smallest type that will hold the values 0..4095.
  84  * On nearly all machines "short" will do nicely.
  85  */
  86
  87 typedef short JSAMPLE;
  88 #define GETJSAMPLE(value)  ((int) (value))
  89
  90 #define MAXJSAMPLE      4095
  91 #define CENTERJSAMPLE   2048
  92
  93 #endif /* BITS_IN_JSAMPLE == 12 */
  94
  95
  96 /* Representation of a DCT frequency coefficient.
  97  * This should be a signed value of at least 16 bits; "short" is usually OK.
  98  * Again, we allocate large arrays of these, but you can change to int
  99  * if you have memory to burn and "short" is really slow.
 100  */
 101
 102 typedef short JCOEF;
 103
 104
 105 /* Compressed datastreams are represented as arrays of JOCTET.
 106  * These must be EXACTLY 8 bits wide, at least once they are written to
 107  * external storage.  Note that when using the stdio data source/destination
 108  * managers, this is also the data type passed to fread/fwrite.
 109  */
 110
 111 #ifdef HAVE_UNSIGNED_CHAR
 112
 113 typedef unsigned char JOCTET;
 114 #define GETJOCTET(value)  (value)
 115
 116 #else /* not HAVE_UNSIGNED_CHAR */
 117
 118 typedef char JOCTET;
 119 #ifdef __CHAR_UNSIGNED__
 120 #define GETJOCTET(value)  (value)
 121 #else
 122 #define GETJOCTET(value)  ((value) & 0xFF)
 123 #endif /* __CHAR_UNSIGNED__ */
 124
 125 #endif /* HAVE_UNSIGNED_CHAR */
 126
 127
 128 /* These typedefs are used for various table entries and so forth.
 129  * They must be at least as wide as specified; but making them too big
 130  * won't cost a huge amount of memory, so we don't provide special
 131  * extraction code like we did for JSAMPLE.  (In other words, these
 132  * typedefs live at a different point on the speed/space tradeoff curve.)
 133  */
 134
 135 /* UINT8 must hold at least the values 0..255. */
 136
 137 typedef uint8_t UINT8;
 138
 139 /* UINT16 must hold at least the values 0..65535. */
 140
 141 typedef uint16_t UINT16;
 142
 143 /* INT16 must hold at least the values -32768..32767. */
 144
 145 typedef int16_t INT16;
 146
 147 /* INT32 must hold at least signed 32-bit values. */
 148
 149 typedef int32_t INT32;
 150
 151 /* Datatype used for image dimensions.  The JPEG standard only supports
 152  * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore
 153  * "unsigned int" is sufficient on all machines.  However, if you need to
 154  * handle larger images and you don't mind deviating from the spec, you
 155  * can change this datatype.
 156  */
 157
 158 typedef unsigned int JDIMENSION;
 159
 160 #define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */
 161
 162
 163 /* These macros are used in all function definitions and extern declarations.
 164  * You could modify them if you need to change function linkage conventions;
 165  * in particular, you'll need to do that to make the library a Windows DLL.
 166  * Another application is to make all functions global for use with debuggers
 167  * or code profilers that require it.
 168  */
 169
 170 /* a function called through method pointers: */
 171 #define METHODDEF(type)         static type
 172 /* a function used only in its module: */
 173 #define LOCAL(type)             static type
 174 /* a function referenced thru EXTERNs: */
 175 #define GLOBAL(type)            type
 176 /* a reference to a GLOBAL function: */
 177 #define EXTERN(type)            extern type
 178
 179
 180 /* This macro is used to declare a "method", that is, a function pointer.
 181  * We want to supply prototype parameters if the compiler can cope.
 182  * Note that the arglist parameter must be parenthesized!
 183  * Again, you can customize this if you need special linkage keywords.
 184  */
 185
 186 #ifdef HAVE_PROTOTYPES
 187 #define JMETHOD(type,methodname,arglist)  type (*methodname) arglist
 188 #else
 189 #define JMETHOD(type,methodname,arglist)  type (*methodname) ()
 190 #endif
 191
 192
 193 /* Here is the pseudo-keyword for declaring pointers that must be "far"
 194  * on 80x86 machines.  Most of the specialized coding for 80x86 is handled
 195  * by just saying "FAR *" where such a pointer is needed.  In a few places
 196  * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
 197  */
 198
 199 #ifdef NEED_FAR_POINTERS
 200 #ifndef FAR
 201 #define FAR  far
 202 #endif
 203 #else
 204 #undef FAR
 205 #define FAR
 206 #endif
 207
 208
 209 /*
 210  * On a few systems, type boolean and/or its values FALSE, TRUE may appear
 211  * in standard header files.  Or you may have conflicts with application-
 212  * specific header files that you want to include together with these files.
 213  * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
 214  */
 215
 216 #ifndef HAVE_BOOLEAN
 217 typedef int boolean;
 218 #endif
 219 #ifndef FALSE                   /* in case these macros already exist */
 220 #define FALSE   0               /* values of boolean */
 221 #endif
 222 #ifndef TRUE
 223 #define TRUE    1
 224 #endif
 225
 226
 227 /*
 228  * The remaining options affect code selection within the JPEG library,
 229  * but they don't need to be visible to most applications using the library.
 230  * To minimize application namespace pollution, the symbols won't be
 231  * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
 232  */
 233
 234 #ifdef JPEG_INTERNALS
 235 #define JPEG_INTERNAL_OPTIONS
 236 #endif
 237
 238 #ifdef JPEG_INTERNAL_OPTIONS
 239
 240
 241 /*
 242  * These defines indicate whether to include various optional functions.
 243  * Undefining some of these symbols will produce a smaller but less capable
 244  * library.  Note that you can leave certain source files out of the
 245  * compilation/linking process if you've #undef'd the corresponding symbols.
 246  * (You may HAVE to do that if your compiler doesn't like null source files.)
 247  */
 248
 249 /* Capability options common to encoder and decoder: */
 250
 251 #define DCT_ISLOW_SUPPORTED     /* slow but accurate integer algorithm */
 252 #define DCT_IFAST_SUPPORTED     /* faster, less accurate integer method */
 253 #define DCT_FLOAT_SUPPORTED     /* floating-point: accurate, fast on fast HW */
 254
 255 /* Encoder capability options: */
 256
 257 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 258 #define C_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 259 #define ENTROPY_OPT_SUPPORTED       /* Optimization of entropy coding parms? */
 260 /* Note: if you selected 12-bit data precision, it is dangerous to turn off
 261  * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit
 262  * precision, so jchuff.c normally uses entropy optimization to compute
 263  * usable tables for higher precision.  If you don't want to do optimization,
 264  * you'll have to supply different default Huffman tables.
 265  * The exact same statements apply for progressive JPEG: the default tables
 266  * don't work for progressive mode.  (This may get fixed, however.)
 267  */
 268 #define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */
 269
 270 /* Decoder capability options: */
 271
 272 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 273 #define D_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 274 #define SAVE_MARKERS_SUPPORTED      /* jpeg_save_markers() needed? */
 275 #define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
 276 #define IDCT_SCALING_SUPPORTED      /* Output rescaling via IDCT? */
 277 #undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
 278 #define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
 279 #define QUANT_1PASS_SUPPORTED       /* 1-pass color quantization? */
 280 #define QUANT_2PASS_SUPPORTED       /* 2-pass color quantization? */
 281
 282 /* more capability options later, no doubt */
 283
 284
 285 /*
 286  * Ordering of RGB data in scanlines passed to or from the application.
 287  * If your application wants to deal with data in the order B,G,R, just
 288  * change these macros.  You can also deal with formats such as R,G,B,X
 289  * (one extra byte per pixel) by changing RGB_PIXELSIZE.  Note that changing
 290  * the offsets will also change the order in which colormap data is organized.
 291  * RESTRICTIONS:
 292  * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
 293  * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
 294  *    useful if you are using JPEG color spaces other than YCbCr or grayscale.
 295  * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
 296  *    is not 3 (they don't understand about dummy color components!).  So you
 297  *    can't use color quantization if you change that value.
 298  */
 299
 300 #define RGB_RED         0       /* Offset of Red in an RGB scanline element */
 301 #define RGB_GREEN       1       /* Offset of Green */
 302 #define RGB_BLUE        2       /* Offset of Blue */
 303 #define RGB_PIXELSIZE   3       /* JSAMPLEs per RGB scanline element */
 304
 305 #define JPEG_NUMCS 16
 306
 307 #define EXT_RGB_RED        0
 308 #define EXT_RGB_GREEN      1
 309 #define EXT_RGB_BLUE       2
 310 #define EXT_RGB_PIXELSIZE  3
 311
 312 #define EXT_RGBX_RED       0
 313 #define EXT_RGBX_GREEN     1
 314 #define EXT_RGBX_BLUE      2
 315 #define EXT_RGBX_PIXELSIZE 4
 316
 317 #define EXT_BGR_RED        2
 318 #define EXT_BGR_GREEN      1
 319 #define EXT_BGR_BLUE       0
 320 #define EXT_BGR_PIXELSIZE  3
 321
 322 #define EXT_BGRX_RED       2
 323 #define EXT_BGRX_GREEN     1
 324 #define EXT_BGRX_BLUE      0
 325 #define EXT_BGRX_PIXELSIZE 4
 326
 327 #define EXT_XBGR_RED       3
 328 #define EXT_XBGR_GREEN     2
 329 #define EXT_XBGR_BLUE      1
 330 #define EXT_XBGR_PIXELSIZE 4
 331
 332 #define EXT_XRGB_RED       1
 333 #define EXT_XRGB_GREEN     2
 334 #define EXT_XRGB_BLUE      3
 335 #define EXT_XRGB_PIXELSIZE 4
 336
 337 static const int rgb_red[JPEG_NUMCS] = {
 338   -1, -1, RGB_RED, -1, -1, -1, EXT_RGB_RED, EXT_RGBX_RED,
 339   EXT_BGR_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED,
 340   EXT_RGBX_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED
 341 };
 342
 343 static const int rgb_green[JPEG_NUMCS] = {
 344   -1, -1, RGB_GREEN, -1, -1, -1, EXT_RGB_GREEN, EXT_RGBX_GREEN,
 345   EXT_BGR_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN,
 346   EXT_RGBX_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN
 347 };
 348
 349 static const int rgb_blue[JPEG_NUMCS] = {
 350   -1, -1, RGB_BLUE, -1, -1, -1, EXT_RGB_BLUE, EXT_RGBX_BLUE,
 351   EXT_BGR_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE,
 352   EXT_RGBX_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE
 353 };
 354
 355 static const int rgb_pixelsize[JPEG_NUMCS] = {
 356   -1, -1, RGB_PIXELSIZE, -1, -1, -1, EXT_RGB_PIXELSIZE, EXT_RGBX_PIXELSIZE,
 357   EXT_BGR_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE,
 358   EXT_RGBX_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE
 359 };
 360
 361 /* Definitions for speed-related optimizations. */
 362
 363 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
 364  * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER
 365  * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.
 366  */
 367
 368 #ifndef MULTIPLIER
 369 #ifndef WITH_SIMD
 370 #define MULTIPLIER  int         /* type for fastest integer multiply */
 371 #else
 372 #define MULTIPLIER short  /* prefer 16-bit with SIMD for parellelism */
 373 #endif
 374 #endif
 375
 376
 377 /* FAST_FLOAT should be either float or double, whichever is done faster
 378  * by your compiler.  (Note that this type is only used in the floating point
 379  * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
 380  * Typically, float is faster in ANSI C compilers, while double is faster in
 381  * pre-ANSI compilers (because they insist on converting to double anyway).
 382  * The code below therefore chooses float if we have ANSI-style prototypes.
 383  */
 384
 385 #ifndef FAST_FLOAT
 386 #ifdef HAVE_PROTOTYPES
 387 #define FAST_FLOAT  float
 388 #else
 389 #define FAST_FLOAT  double
 390 #endif
 391 #endif
 392
 393 #endif /* JPEG_INTERNAL_OPTIONS */