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  * Modified 1997-2009 by Guido Vollbeding.
   7  * libjpeg-turbo Modifications:
   8  * Copyright (C) 2009, 2011, 2014-2015, 2018, 2020, D. R. Commander.
   9  * For conditions of distribution and use, see the accompanying README.ijg
  10  * file.
  11  *
  12  * This file contains additional configuration options that customize the
  13  * JPEG software for special applications or support machine-dependent
  14  * optimizations.  Most users will not need to touch this file.
  15  */
  16
  17 #include <stdint.h>
  18
  19 /*
  20  * Maximum number of components (color channels) allowed in JPEG image.
  21  * To meet the letter of Rec. ITU-T T.81 | ISO/IEC 10918-1, set this to 255.
  22  * However, darn few applications need more than 4 channels (maybe 5 for CMYK +
  23  * alpha mask).  We recommend 10 as a reasonable compromise; use 4 if you are
  24  * really short on memory.  (Each allowed component costs a hundred or so
  25  * bytes of storage, whether actually used in an image or not.)
  26  */
  27
  28 #define MAX_COMPONENTS  10      /* maximum number of image components */
  29
  30
  31 /*
  32  * Basic data types.
  33  * You may need to change these if you have a machine with unusual data
  34  * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
  35  * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits,
  36  * but it had better be at least 16.
  37  */
  38
  39 /* Representation of a single sample (pixel element value).
  40  * We frequently allocate large arrays of these, so it's important to keep
  41  * them small.  But if you have memory to burn and access to char or short
  42  * arrays is very slow on your hardware, you might want to change these.
  43  */
  44
  45 #if BITS_IN_JSAMPLE == 8
  46 /* JSAMPLE should be the smallest type that will hold the values 0..255.
  47  */
  48
  49 typedef unsigned char JSAMPLE;
  50 #define GETJSAMPLE(value)  ((int)(value))
  51
  52 #define MAXJSAMPLE      255
  53 #define CENTERJSAMPLE   128
  54
  55 #endif /* BITS_IN_JSAMPLE == 8 */
  56
  57
  58 #if BITS_IN_JSAMPLE == 12
  59 /* JSAMPLE should be the smallest type that will hold the values 0..4095.
  60  * On nearly all machines "short" will do nicely.
  61  */
  62
  63 typedef short JSAMPLE;
  64 #define GETJSAMPLE(value)  ((int)(value))
  65
  66 #define MAXJSAMPLE      4095
  67 #define CENTERJSAMPLE   2048
  68
  69 #endif /* BITS_IN_JSAMPLE == 12 */
  70
  71
  72 /* Representation of a DCT frequency coefficient.
  73  * This should be a signed value of at least 16 bits; "short" is usually OK.
  74  * Again, we allocate large arrays of these, but you can change to int
  75  * if you have memory to burn and "short" is really slow.
  76  */
  77
  78 typedef short JCOEF;
  79
  80
  81 /* Compressed datastreams are represented as arrays of JOCTET.
  82  * These must be EXACTLY 8 bits wide, at least once they are written to
  83  * external storage.  Note that when using the stdio data source/destination
  84  * managers, this is also the data type passed to fread/fwrite.
  85  */
  86
  87 typedef unsigned char JOCTET;
  88 #define GETJOCTET(value)  (value)
  89
  90
  91 /* These typedefs are used for various table entries and so forth.
  92  * They must be at least as wide as specified; but making them too big
  93  * won't cost a huge amount of memory, so we don't provide special
  94  * extraction code like we did for JSAMPLE.  (In other words, these
  95  * typedefs live at a different point on the speed/space tradeoff curve.)
  96  */
  97
  98 /* UINT8 must hold at least the values 0..255. */
  99
 100 typedef uint8_t UINT8;
 101
 102 /* UINT16 must hold at least the values 0..65535. */
 103
 104 typedef uint16_t UINT16;
 105
 106 /* INT16 must hold at least the values -32768..32767. */
 107
 108 typedef int16_t INT16;
 109
 110 /* INT32 must hold at least signed 32-bit values.
 111  *
 112  * NOTE: The INT32 typedef dates back to libjpeg v5 (1994.)  Integers were
 113  * sometimes 16-bit back then (MS-DOS), which is why INT32 is typedef'd to
 114  * long.  It also wasn't common (or at least as common) in 1994 for INT32 to be
 115  * defined by platform headers.  Since then, however, INT32 is defined in
 116  * several other common places:
 117  *
 118  * Xmd.h (X11 header) typedefs INT32 to int on 64-bit platforms and long on
 119  * 32-bit platforms (i.e always a 32-bit signed type.)
 120  *
 121  * basetsd.h (Win32 header) typedefs INT32 to int (always a 32-bit signed type
 122  * on modern platforms.)
 123  *
 124  * qglobal.h (Qt header) typedefs INT32 to int (always a 32-bit signed type on
 125  * modern platforms.)
 126  *
 127  * This is a recipe for conflict, since "long" and "int" aren't always
 128  * compatible types.  Since the definition of INT32 has technically been part
 129  * of the libjpeg API for more than 20 years, we can't remove it, but we do not
 130  * use it internally any longer.  We instead define a separate type (JLONG)
 131  * for internal use, which ensures that internal behavior will always be the
 132  * same regardless of any external headers that may be included.
 133  */
 134
 135 typedef int32_t INT32;
 136
 137 /* Datatype used for image dimensions.  The JPEG standard only supports
 138  * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore
 139  * "unsigned int" is sufficient on all machines.  However, if you need to
 140  * handle larger images and you don't mind deviating from the spec, you
 141  * can change this datatype.  (Note that changing this datatype will
 142  * potentially require modifying the SIMD code.  The x86-64 SIMD extensions,
 143  * in particular, assume a 32-bit JDIMENSION.)
 144  */
 145
 146 typedef unsigned int JDIMENSION;
 147
 148 #define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */
 149
 150
 151 /* These macros are used in all function definitions and extern declarations.
 152  * You could modify them if you need to change function linkage conventions;
 153  * in particular, you'll need to do that to make the library a Windows DLL.
 154  * Another application is to make all functions global for use with debuggers
 155  * or code profilers that require it.
 156  */
 157
 158 /* a function called through method pointers: */
 159 #define METHODDEF(type)         static type
 160 /* a function used only in its module: */
 161 #define LOCAL(type)             static type
 162 /* a function referenced thru EXTERNs: */
 163 #define GLOBAL(type)            type
 164 /* a reference to a GLOBAL function: */
 165 #define EXTERN(type)            extern type
 166
 167
 168 /* Originally, this macro was used as a way of defining function prototypes
 169  * for both modern compilers as well as older compilers that did not support
 170  * prototype parameters.  libjpeg-turbo has never supported these older,
 171  * non-ANSI compilers, but the macro is still included because there is some
 172  * software out there that uses it.
 173  */
 174
 175 #define JMETHOD(type, methodname, arglist)  type (*methodname) arglist
 176
 177
 178 /* libjpeg-turbo no longer supports platforms that have far symbols (MS-DOS),
 179  * but again, some software relies on this macro.
 180  */
 181
 182 #undef FAR
 183 #define FAR
 184
 185
 186 /*
 187  * On a few systems, type boolean and/or its values FALSE, TRUE may appear
 188  * in standard header files.  Or you may have conflicts with application-
 189  * specific header files that you want to include together with these files.
 190  * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
 191  */
 192
 193 #ifndef HAVE_BOOLEAN
 194 typedef int boolean;
 195 #endif
 196 #ifndef FALSE                   /* in case these macros already exist */
 197 #define FALSE   0               /* values of boolean */
 198 #endif
 199 #ifndef TRUE
 200 #define TRUE    1
 201 #endif
 202
 203
 204 /*
 205  * The remaining options affect code selection within the JPEG library,
 206  * but they don't need to be visible to most applications using the library.
 207  * To minimize application namespace pollution, the symbols won't be
 208  * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
 209  */
 210
 211 #ifdef JPEG_INTERNALS
 212 #define JPEG_INTERNAL_OPTIONS
 213 #endif
 214
 215 #ifdef JPEG_INTERNAL_OPTIONS
 216
 217
 218 /*
 219  * These defines indicate whether to include various optional functions.
 220  * Undefining some of these symbols will produce a smaller but less capable
 221  * library.  Note that you can leave certain source files out of the
 222  * compilation/linking process if you've #undef'd the corresponding symbols.
 223  * (You may HAVE to do that if your compiler doesn't like null source files.)
 224  */
 225
 226 /* Capability options common to encoder and decoder: */
 227
 228 #define DCT_ISLOW_SUPPORTED     /* accurate integer method */
 229 #define DCT_IFAST_SUPPORTED     /* less accurate int method [legacy feature] */
 230 #define DCT_FLOAT_SUPPORTED     /* floating-point method [legacy feature] */
 231
 232 /* Encoder capability options: */
 233
 234 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 235 #define C_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 236 #define ENTROPY_OPT_SUPPORTED       /* Optimization of entropy coding parms? */
 237 /* Note: if you selected 12-bit data precision, it is dangerous to turn off
 238  * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit
 239  * precision, so jchuff.c normally uses entropy optimization to compute
 240  * usable tables for higher precision.  If you don't want to do optimization,
 241  * you'll have to supply different default Huffman tables.
 242  * The exact same statements apply for progressive JPEG: the default tables
 243  * don't work for progressive mode.  (This may get fixed, however.)
 244  */
 245 #define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */
 246
 247 /* Decoder capability options: */
 248
 249 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
 250 #define D_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
 251 #define SAVE_MARKERS_SUPPORTED      /* jpeg_save_markers() needed? */
 252 #define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
 253 #define IDCT_SCALING_SUPPORTED      /* Output rescaling via IDCT? */
 254 #undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
 255 #define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
 256 #define QUANT_1PASS_SUPPORTED       /* 1-pass color quantization? */
 257 #define QUANT_2PASS_SUPPORTED       /* 2-pass color quantization? */
 258
 259 /* more capability options later, no doubt */
 260
 261
 262 /*
 263  * The RGB_RED, RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros are a vestigial
 264  * feature of libjpeg.  The idea was that, if an application developer needed
 265  * to compress from/decompress to a BGR/BGRX/RGBX/XBGR/XRGB buffer, they could
 266  * change these macros, rebuild libjpeg, and link their application statically
 267  * with it.  In reality, few people ever did this, because there were some
 268  * severe restrictions involved (cjpeg and djpeg no longer worked properly,
 269  * compressing/decompressing RGB JPEGs no longer worked properly, and the color
 270  * quantizer wouldn't work with pixel sizes other than 3.)  Furthermore, since
 271  * all of the O/S-supplied versions of libjpeg were built with the default
 272  * values of RGB_RED, RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE, many applications
 273  * have come to regard these values as immutable.
 274  *
 275  * The libjpeg-turbo colorspace extensions provide a much cleaner way of
 276  * compressing from/decompressing to buffers with arbitrary component orders
 277  * and pixel sizes.  Thus, we do not support changing the values of RGB_RED,
 278  * RGB_GREEN, RGB_BLUE, or RGB_PIXELSIZE.  In addition to the restrictions
 279  * listed above, changing these values will also break the SIMD extensions and
 280  * the regression tests.
 281  */
 282
 283 #define RGB_RED         0       /* Offset of Red in an RGB scanline element */
 284 #define RGB_GREEN       1       /* Offset of Green */
 285 #define RGB_BLUE        2       /* Offset of Blue */
 286 #define RGB_PIXELSIZE   3       /* JSAMPLEs per RGB scanline element */
 287
 288 #define JPEG_NUMCS  17
 289
 290 #define EXT_RGB_RED         0
 291 #define EXT_RGB_GREEN       1
 292 #define EXT_RGB_BLUE        2
 293 #define EXT_RGB_PIXELSIZE   3
 294
 295 #define EXT_RGBX_RED        0
 296 #define EXT_RGBX_GREEN      1
 297 #define EXT_RGBX_BLUE       2
 298 #define EXT_RGBX_PIXELSIZE  4
 299
 300 #define EXT_BGR_RED         2
 301 #define EXT_BGR_GREEN       1
 302 #define EXT_BGR_BLUE        0
 303 #define EXT_BGR_PIXELSIZE   3
 304
 305 #define EXT_BGRX_RED        2
 306 #define EXT_BGRX_GREEN      1
 307 #define EXT_BGRX_BLUE       0
 308 #define EXT_BGRX_PIXELSIZE  4
 309
 310 #define EXT_XBGR_RED        3
 311 #define EXT_XBGR_GREEN      2
 312 #define EXT_XBGR_BLUE       1
 313 #define EXT_XBGR_PIXELSIZE  4
 314
 315 #define EXT_XRGB_RED        1
 316 #define EXT_XRGB_GREEN      2
 317 #define EXT_XRGB_BLUE       3
 318 #define EXT_XRGB_PIXELSIZE  4
 319
 320 static const int rgb_red[JPEG_NUMCS] = {
 321   -1, -1, RGB_RED, -1, -1, -1, EXT_RGB_RED, EXT_RGBX_RED,
 322   EXT_BGR_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED,
 323   EXT_RGBX_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED,
 324   -1
 325 };
 326
 327 static const int rgb_green[JPEG_NUMCS] = {
 328   -1, -1, RGB_GREEN, -1, -1, -1, EXT_RGB_GREEN, EXT_RGBX_GREEN,
 329   EXT_BGR_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN,
 330   EXT_RGBX_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN,
 331   -1
 332 };
 333
 334 static const int rgb_blue[JPEG_NUMCS] = {
 335   -1, -1, RGB_BLUE, -1, -1, -1, EXT_RGB_BLUE, EXT_RGBX_BLUE,
 336   EXT_BGR_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE,
 337   EXT_RGBX_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE,
 338   -1
 339 };
 340
 341 static const int rgb_pixelsize[JPEG_NUMCS] = {
 342   -1, -1, RGB_PIXELSIZE, -1, -1, -1, EXT_RGB_PIXELSIZE, EXT_RGBX_PIXELSIZE,
 343   EXT_BGR_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE,
 344   EXT_RGBX_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE,
 345   -1
 346 };
 347
 348 /* Definitions for speed-related optimizations. */
 349
 350 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
 351  * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER
 352  * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.
 353  */
 354
 355 #ifndef MULTIPLIER
 356 #ifndef WITH_SIMD
 357 #define MULTIPLIER  int         /* type for fastest integer multiply */
 358 #else
 359 #define MULTIPLIER  short       /* prefer 16-bit with SIMD for parellelism */
 360 #endif
 361 #endif
 362
 363
 364 /* FAST_FLOAT should be either float or double, whichever is done faster
 365  * by your compiler.  (Note that this type is only used in the floating point
 366  * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
 367  */
 368
 369 #ifndef FAST_FLOAT
 370 #define FAST_FLOAT  float
 371 #endif
 372
 373 #endif /* JPEG_INTERNAL_OPTIONS */