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      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, 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 
     18 /*
     19  * Maximum number of components (color channels) allowed in JPEG image.
     20  * To meet the letter of the JPEG spec, set this to 255.  However, darn
     21  * few applications need more than 4 channels (maybe 5 for CMYK + alpha
     22  * mask).  We recommend 10 as a reasonable compromise; use 4 if you are
     23  * really short on memory.  (Each allowed component costs a hundred or so
     24  * bytes of storage, whether actually used in an image or not.)
     25  */
     26 
     27 #define MAX_COMPONENTS  10      /* maximum number of image components */
     28 
     29 
     30 /*
     31  * Basic data types.
     32  * You may need to change these if you have a machine with unusual data
     33  * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
     34  * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits,
     35  * but it had better be at least 16.
     36  */
     37 
     38 /* Representation of a single sample (pixel element value).
     39  * We frequently allocate large arrays of these, so it's important to keep
     40  * them small.  But if you have memory to burn and access to char or short
     41  * arrays is very slow on your hardware, you might want to change these.
     42  */
     43 
     44 #if BITS_IN_JSAMPLE == 8
     45 /* JSAMPLE should be the smallest type that will hold the values 0..255.
     46  * You can use a signed char by having GETJSAMPLE mask it with 0xFF.
     47  */
     48 
     49 #ifdef HAVE_UNSIGNED_CHAR
     50 
     51 typedef unsigned char JSAMPLE;
     52 #define GETJSAMPLE(value)  ((int) (value))
     53 
     54 #else /* not HAVE_UNSIGNED_CHAR */
     55 
     56 typedef char JSAMPLE;
     57 #ifdef __CHAR_UNSIGNED__
     58 #define GETJSAMPLE(value)  ((int) (value))
     59 #else
     60 #define GETJSAMPLE(value)  ((int) (value) & 0xFF)
     61 #endif /* __CHAR_UNSIGNED__ */
     62 
     63 #endif /* HAVE_UNSIGNED_CHAR */
     64 
     65 #define MAXJSAMPLE      255
     66 #define CENTERJSAMPLE   128
     67 
     68 #endif /* BITS_IN_JSAMPLE == 8 */
     69 
     70 
     71 #if BITS_IN_JSAMPLE == 12
     72 /* JSAMPLE should be the smallest type that will hold the values 0..4095.
     73  * On nearly all machines "short" will do nicely.
     74  */
     75 
     76 typedef short JSAMPLE;
     77 #define GETJSAMPLE(value)  ((int) (value))
     78 
     79 #define MAXJSAMPLE      4095
     80 #define CENTERJSAMPLE   2048
     81 
     82 #endif /* BITS_IN_JSAMPLE == 12 */
     83 
     84 
     85 /* Representation of a DCT frequency coefficient.
     86  * This should be a signed value of at least 16 bits; "short" is usually OK.
     87  * Again, we allocate large arrays of these, but you can change to int
     88  * if you have memory to burn and "short" is really slow.
     89  */
     90 
     91 typedef short JCOEF;
     92 
     93 
     94 /* Compressed datastreams are represented as arrays of JOCTET.
     95  * These must be EXACTLY 8 bits wide, at least once they are written to
     96  * external storage.  Note that when using the stdio data source/destination
     97  * managers, this is also the data type passed to fread/fwrite.
     98  */
     99 
    100 #ifdef HAVE_UNSIGNED_CHAR
    101 
    102 typedef unsigned char JOCTET;
    103 #define GETJOCTET(value)  (value)
    104 
    105 #else /* not HAVE_UNSIGNED_CHAR */
    106 
    107 typedef char JOCTET;
    108 #ifdef __CHAR_UNSIGNED__
    109 #define GETJOCTET(value)  (value)
    110 #else
    111 #define GETJOCTET(value)  ((value) & 0xFF)
    112 #endif /* __CHAR_UNSIGNED__ */
    113 
    114 #endif /* HAVE_UNSIGNED_CHAR */
    115 
    116 
    117 /* These typedefs are used for various table entries and so forth.
    118  * They must be at least as wide as specified; but making them too big
    119  * won't cost a huge amount of memory, so we don't provide special
    120  * extraction code like we did for JSAMPLE.  (In other words, these
    121  * typedefs live at a different point on the speed/space tradeoff curve.)
    122  */
    123 
    124 /* UINT8 must hold at least the values 0..255. */
    125 
    126 #ifdef HAVE_UNSIGNED_CHAR
    127 typedef unsigned char UINT8;
    128 #else /* not HAVE_UNSIGNED_CHAR */
    129 #ifdef __CHAR_UNSIGNED__
    130 typedef char UINT8;
    131 #else /* not __CHAR_UNSIGNED__ */
    132 typedef short UINT8;
    133 #endif /* __CHAR_UNSIGNED__ */
    134 #endif /* HAVE_UNSIGNED_CHAR */
    135 
    136 /* UINT16 must hold at least the values 0..65535. */
    137 
    138 #ifdef HAVE_UNSIGNED_SHORT
    139 typedef unsigned short UINT16;
    140 #else /* not HAVE_UNSIGNED_SHORT */
    141 typedef unsigned int UINT16;
    142 #endif /* HAVE_UNSIGNED_SHORT */
    143 
    144 /* INT16 must hold at least the values -32768..32767. */
    145 
    146 #ifndef XMD_H                   /* X11/xmd.h correctly defines INT16 */
    147 typedef short INT16;
    148 #endif
    149 
    150 /* INT32 must hold at least signed 32-bit values.
    151  *
    152  * NOTE: The INT32 typedef dates back to libjpeg v5 (1994.)  Integers were
    153  * sometimes 16-bit back then (MS-DOS), which is why INT32 is typedef'd to
    154  * long.  It also wasn't common (or at least as common) in 1994 for INT32 to be
    155  * defined by platform headers.  Since then, however, INT32 is defined in
    156  * several other common places:
    157  *
    158  * Xmd.h (X11 header) typedefs INT32 to int on 64-bit platforms and long on
    159  * 32-bit platforms (i.e always a 32-bit signed type.)
    160  *
    161  * basetsd.h (Win32 header) typedefs INT32 to int (always a 32-bit signed type
    162  * on modern platforms.)
    163  *
    164  * qglobal.h (Qt header) typedefs INT32 to int (always a 32-bit signed type on
    165  * modern platforms.)
    166  *
    167  * This is a recipe for conflict, since "long" and "int" aren't always
    168  * compatible types.  Since the definition of INT32 has technically been part
    169  * of the libjpeg API for more than 20 years, we can't remove it, but we do not
    170  * use it internally any longer.  We instead define a separate type (JLONG)
    171  * for internal use, which ensures that internal behavior will always be the
    172  * same regardless of any external headers that may be included.
    173  */
    174 
    175 #ifndef XMD_H                   /* X11/xmd.h correctly defines INT32 */
    176 #ifndef _BASETSD_H_		/* Microsoft defines it in basetsd.h */
    177 #ifndef _BASETSD_H		/* MinGW is slightly different */
    178 #ifndef QGLOBAL_H		/* Qt defines it in qglobal.h */
    179 typedef long INT32;
    180 #endif
    181 #endif
    182 #endif
    183 #endif
    184 
    185 /* Datatype used for image dimensions.  The JPEG standard only supports
    186  * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore
    187  * "unsigned int" is sufficient on all machines.  However, if you need to
    188  * handle larger images and you don't mind deviating from the spec, you
    189  * can change this datatype.  (Note that changing this datatype will
    190  * potentially require modifying the SIMD code.  The x86-64 SIMD extensions,
    191  * in particular, assume a 32-bit JDIMENSION.)
    192  */
    193 
    194 typedef unsigned int JDIMENSION;
    195 
    196 #define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */
    197 
    198 
    199 /* These macros are used in all function definitions and extern declarations.
    200  * You could modify them if you need to change function linkage conventions;
    201  * in particular, you'll need to do that to make the library a Windows DLL.
    202  * Another application is to make all functions global for use with debuggers
    203  * or code profilers that require it.
    204  */
    205 
    206 /* a function called through method pointers: */
    207 #define METHODDEF(type)         static type
    208 /* a function used only in its module: */
    209 #define LOCAL(type)             static type
    210 /* a function referenced thru EXTERNs: */
    211 #define GLOBAL(type)            type
    212 /* a reference to a GLOBAL function: */
    213 #define EXTERN(type)            extern type
    214 
    215 
    216 /* Originally, this macro was used as a way of defining function prototypes
    217  * for both modern compilers as well as older compilers that did not support
    218  * prototype parameters.  libjpeg-turbo has never supported these older,
    219  * non-ANSI compilers, but the macro is still included because there is some
    220  * software out there that uses it.
    221  */
    222 
    223 #define JMETHOD(type,methodname,arglist)  type (*methodname) arglist
    224 
    225 
    226 /* libjpeg-turbo no longer supports platforms that have far symbols (MS-DOS),
    227  * but again, some software relies on this macro.
    228  */
    229 
    230 #undef FAR
    231 #define FAR
    232 
    233 
    234 /*
    235  * On a few systems, type boolean and/or its values FALSE, TRUE may appear
    236  * in standard header files.  Or you may have conflicts with application-
    237  * specific header files that you want to include together with these files.
    238  * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
    239  */
    240 
    241 #ifndef HAVE_BOOLEAN
    242 typedef int boolean;
    243 #endif
    244 #ifndef FALSE                   /* in case these macros already exist */
    245 #define FALSE   0               /* values of boolean */
    246 #endif
    247 #ifndef TRUE
    248 #define TRUE    1
    249 #endif
    250 
    251 
    252 /*
    253  * The remaining options affect code selection within the JPEG library,
    254  * but they don't need to be visible to most applications using the library.
    255  * To minimize application namespace pollution, the symbols won't be
    256  * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
    257  */
    258 
    259 #ifdef JPEG_INTERNALS
    260 #define JPEG_INTERNAL_OPTIONS
    261 #endif
    262 
    263 #ifdef JPEG_INTERNAL_OPTIONS
    264 
    265 
    266 /*
    267  * These defines indicate whether to include various optional functions.
    268  * Undefining some of these symbols will produce a smaller but less capable
    269  * library.  Note that you can leave certain source files out of the
    270  * compilation/linking process if you've #undef'd the corresponding symbols.
    271  * (You may HAVE to do that if your compiler doesn't like null source files.)
    272  */
    273 
    274 /* Capability options common to encoder and decoder: */
    275 
    276 #define DCT_ISLOW_SUPPORTED     /* slow but accurate integer algorithm */
    277 #define DCT_IFAST_SUPPORTED     /* faster, less accurate integer method */
    278 #define DCT_FLOAT_SUPPORTED     /* floating-point: accurate, fast on fast HW */
    279 
    280 /* Encoder capability options: */
    281 
    282 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
    283 #define C_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
    284 #define ENTROPY_OPT_SUPPORTED       /* Optimization of entropy coding parms? */
    285 /* Note: if you selected 12-bit data precision, it is dangerous to turn off
    286  * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit
    287  * precision, so jchuff.c normally uses entropy optimization to compute
    288  * usable tables for higher precision.  If you don't want to do optimization,
    289  * you'll have to supply different default Huffman tables.
    290  * The exact same statements apply for progressive JPEG: the default tables
    291  * don't work for progressive mode.  (This may get fixed, however.)
    292  */
    293 #define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */
    294 
    295 /* Decoder capability options: */
    296 
    297 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
    298 #define D_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
    299 #define SAVE_MARKERS_SUPPORTED      /* jpeg_save_markers() needed? */
    300 #define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
    301 #define IDCT_SCALING_SUPPORTED      /* Output rescaling via IDCT? */
    302 #undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
    303 #define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
    304 #define QUANT_1PASS_SUPPORTED       /* 1-pass color quantization? */
    305 #define QUANT_2PASS_SUPPORTED       /* 2-pass color quantization? */
    306 
    307 /* more capability options later, no doubt */
    308 
    309 
    310 /*
    311  * The RGB_RED, RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros are a vestigial
    312  * feature of libjpeg.  The idea was that, if an application developer needed
    313  * to compress from/decompress to a BGR/BGRX/RGBX/XBGR/XRGB buffer, they could
    314  * change these macros, rebuild libjpeg, and link their application statically
    315  * with it.  In reality, few people ever did this, because there were some
    316  * severe restrictions involved (cjpeg and djpeg no longer worked properly,
    317  * compressing/decompressing RGB JPEGs no longer worked properly, and the color
    318  * quantizer wouldn't work with pixel sizes other than 3.)  Further, since all
    319  * of the O/S-supplied versions of libjpeg were built with the default values
    320  * of RGB_RED, RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE, many applications have
    321  * come to regard these values as immutable.
    322  *
    323  * The libjpeg-turbo colorspace extensions provide a much cleaner way of
    324  * compressing from/decompressing to buffers with arbitrary component orders
    325  * and pixel sizes.  Thus, we do not support changing the values of RGB_RED,
    326  * RGB_GREEN, RGB_BLUE, or RGB_PIXELSIZE.  In addition to the restrictions
    327  * listed above, changing these values will also break the SIMD extensions and
    328  * the regression tests.
    329  */
    330 
    331 #define RGB_RED         0       /* Offset of Red in an RGB scanline element */
    332 #define RGB_GREEN       1       /* Offset of Green */
    333 #define RGB_BLUE        2       /* Offset of Blue */
    334 #define RGB_PIXELSIZE   3       /* JSAMPLEs per RGB scanline element */
    335 
    336 #define JPEG_NUMCS 17
    337 
    338 #define EXT_RGB_RED        0
    339 #define EXT_RGB_GREEN      1
    340 #define EXT_RGB_BLUE       2
    341 #define EXT_RGB_PIXELSIZE  3
    342 
    343 #define EXT_RGBX_RED       0
    344 #define EXT_RGBX_GREEN     1
    345 #define EXT_RGBX_BLUE      2
    346 #define EXT_RGBX_PIXELSIZE 4
    347 
    348 #define EXT_BGR_RED        2
    349 #define EXT_BGR_GREEN      1
    350 #define EXT_BGR_BLUE       0
    351 #define EXT_BGR_PIXELSIZE  3
    352 
    353 #define EXT_BGRX_RED       2
    354 #define EXT_BGRX_GREEN     1
    355 #define EXT_BGRX_BLUE      0
    356 #define EXT_BGRX_PIXELSIZE 4
    357 
    358 #define EXT_XBGR_RED       3
    359 #define EXT_XBGR_GREEN     2
    360 #define EXT_XBGR_BLUE      1
    361 #define EXT_XBGR_PIXELSIZE 4
    362 
    363 #define EXT_XRGB_RED       1
    364 #define EXT_XRGB_GREEN     2
    365 #define EXT_XRGB_BLUE      3
    366 #define EXT_XRGB_PIXELSIZE 4
    367 
    368 static const int rgb_red[JPEG_NUMCS] = {
    369   -1, -1, RGB_RED, -1, -1, -1, EXT_RGB_RED, EXT_RGBX_RED,
    370   EXT_BGR_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED,
    371   EXT_RGBX_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED,
    372   -1
    373 };
    374 
    375 static const int rgb_green[JPEG_NUMCS] = {
    376   -1, -1, RGB_GREEN, -1, -1, -1, EXT_RGB_GREEN, EXT_RGBX_GREEN,
    377   EXT_BGR_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN,
    378   EXT_RGBX_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN,
    379   -1
    380 };
    381 
    382 static const int rgb_blue[JPEG_NUMCS] = {
    383   -1, -1, RGB_BLUE, -1, -1, -1, EXT_RGB_BLUE, EXT_RGBX_BLUE,
    384   EXT_BGR_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE,
    385   EXT_RGBX_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE,
    386   -1
    387 };
    388 
    389 static const int rgb_pixelsize[JPEG_NUMCS] = {
    390   -1, -1, RGB_PIXELSIZE, -1, -1, -1, EXT_RGB_PIXELSIZE, EXT_RGBX_PIXELSIZE,
    391   EXT_BGR_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE,
    392   EXT_RGBX_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE,
    393   -1
    394 };
    395 
    396 /* Definitions for speed-related optimizations. */
    397 
    398 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
    399  * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER
    400  * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.
    401  */
    402 
    403 #ifndef MULTIPLIER
    404 #ifndef WITH_SIMD
    405 #define MULTIPLIER  int         /* type for fastest integer multiply */
    406 #else
    407 #define MULTIPLIER short  /* prefer 16-bit with SIMD for parellelism */
    408 #endif
    409 #endif
    410 
    411 
    412 /* FAST_FLOAT should be either float or double, whichever is done faster
    413  * by your compiler.  (Note that this type is only used in the floating point
    414  * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
    415  */
    416 
    417 #ifndef FAST_FLOAT
    418 #define FAST_FLOAT  float
    419 #endif
    420 
    421 #endif /* JPEG_INTERNAL_OPTIONS */
    422