0N/A * reserved comment block 0N/A * DO NOT REMOVE OR ALTER! 0N/A * Copyright (C) 1991-1997, Thomas G. Lane. 0N/A * This file is part of the Independent JPEG Group's software. 0N/A * For conditions of distribution and use, see the accompanying README file. 0N/A * This file contains additional configuration options that customize the 0N/A * JPEG software for special applications or support machine-dependent 0N/A * optimizations. Most users will not need to touch this file. 0N/A * Define BITS_IN_JSAMPLE as either 0N/A * 8 for 8-bit sample values (the usual setting) 0N/A * 12 for 12-bit sample values 0N/A * Only 8 and 12 are legal data precisions for lossy JPEG according to the 0N/A * JPEG standard, and the IJG code does not support anything else! 0N/A * We do not support run-time selection of data precision, sorry. 0N/A * Maximum number of components (color channels) allowed in JPEG image. 0N/A * To meet the letter of the JPEG spec, set this to 255. However, darn 0N/A * few applications need more than 4 channels (maybe 5 for CMYK + alpha 0N/A * mask). We recommend 10 as a reasonable compromise; use 4 if you are 0N/A * really short on memory. (Each allowed component costs a hundred or so 0N/A * bytes of storage, whether actually used in an image or not.) 0N/A * You may need to change these if you have a machine with unusual data 0N/A * type sizes; for example, "char" not 8 bits, "short" not 16 bits, 0N/A * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, 0N/A * but it had better be at least 16. 0N/A/* Representation of a single sample (pixel element value). 0N/A * We frequently allocate large arrays of these, so it's important to keep 0N/A * them small. But if you have memory to burn and access to char or short 0N/A * arrays is very slow on your hardware, you might want to change these. 0N/A/* JSAMPLE should be the smallest type that will hold the values 0..255. 0N/A * You can use a signed char by having GETJSAMPLE mask it with 0xFF. 0N/A#
else /* not HAVE_UNSIGNED_CHAR */ 0N/A#
endif /* CHAR_IS_UNSIGNED */ 0N/A#
endif /* HAVE_UNSIGNED_CHAR */ 0N/A#
endif /* BITS_IN_JSAMPLE == 8 */ 0N/A/* JSAMPLE should be the smallest type that will hold the values 0..4095. 0N/A * On nearly all machines "short" will do nicely. 0N/A#
endif /* BITS_IN_JSAMPLE == 12 */ 0N/A/* Representation of a DCT frequency coefficient. 0N/A * This should be a signed value of at least 16 bits; "short" is usually OK. 0N/A * Again, we allocate large arrays of these, but you can change to int 0N/A * if you have memory to burn and "short" is really slow. 0N/A/* Compressed datastreams are represented as arrays of JOCTET. 0N/A * These must be EXACTLY 8 bits wide, at least once they are written to 0N/A#
else /* not HAVE_UNSIGNED_CHAR */ 0N/A#
endif /* CHAR_IS_UNSIGNED */ 0N/A#
endif /* HAVE_UNSIGNED_CHAR */ 0N/A/* These typedefs are used for various table entries and so forth. 0N/A * They must be at least as wide as specified; but making them too big 0N/A * won't cost a huge amount of memory, so we don't provide special 0N/A * extraction code like we did for JSAMPLE. (In other words, these 0N/A * typedefs live at a different point on the speed/space tradeoff curve.) 0N/A/* UINT8 must hold at least the values 0..255. */ 0N/A#
else /* not HAVE_UNSIGNED_CHAR */ 0N/A#
else /* not CHAR_IS_UNSIGNED */ 0N/A#
endif /* CHAR_IS_UNSIGNED */ 0N/A#
endif /* HAVE_UNSIGNED_CHAR */ 0N/A/* UINT16 must hold at least the values 0..65535. */ 0N/A#
else /* not HAVE_UNSIGNED_SHORT */ 0N/A#
endif /* HAVE_UNSIGNED_SHORT */ 0N/A/* INT16 must hold at least the values -32768..32767. */ 0N/A/* INT32 must hold at least signed 32-bit values. */ 3362N/A#
if defined(
_LP64) ||
defined(
_WIN32)
/* _WIN32 is on all windows platfroms (x86 and x64) */ 0N/A/* Datatype used for image dimensions. The JPEG standard only supports 0N/A * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore 0N/A * "unsigned int" is sufficient on all machines. However, if you need to 0N/A * handle larger images and you don't mind deviating from the spec, you 0N/A * can change this datatype. 0N/A/* These macros are used in all function definitions and extern declarations. 0N/A * You could modify them if you need to change function linkage conventions; 0N/A * in particular, you'll need to do that to make the library a Windows DLL. 0N/A * Another application is to make all functions global for use with debuggers 0N/A * or code profilers that require it. 0N/A/* a function called through method pointers: */ 0N/A/* a function used only in its module: */ 0N/A/* a function referenced thru EXTERNs: */ 0N/A/* a reference to a GLOBAL function: */ 0N/A/* This macro is used to declare a "method", that is, a function pointer. 0N/A * We want to supply prototype parameters if the compiler can cope. 0N/A * Note that the arglist parameter must be parenthesized! 0N/A * Again, you can customize this if you need special linkage keywords. 0N/A/* Here is the pseudo-keyword for declaring pointers that must be "far" 0N/A * on 80x86 machines. Most of the specialized coding for 80x86 is handled 0N/A * by just saying "FAR *" where such a pointer is needed. In a few places 0N/A * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. 0N/A * On a few systems, type boolean and/or its values FALSE, TRUE may appear 0N/A * in standard header files. Or you may have conflicts with application- 0N/A * specific header files that you want to include together with these files. 0N/A * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. 0N/A#
ifndef FALSE /* in case these macros already exist */ 0N/A * The remaining options affect code selection within the JPEG library, 0N/A * but they don't need to be visible to most applications using the library. 0N/A * To minimize application namespace pollution, the symbols won't be 0N/A * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. 0N/A * These defines indicate whether to include various optional functions. 0N/A * Undefining some of these symbols will produce a smaller but less capable 0N/A * library. Note that you can leave certain source files out of the 0N/A * (You may HAVE to do that if your compiler doesn't like null source files.) 0N/A/* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */ 0N/A/* Capability options common to encoder and decoder: */ 0N/A/* Encoder capability options: */ 0N/A/* Note: if you selected 12-bit data precision, it is dangerous to turn off 0N/A * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit 0N/A * precision, so jchuff.c normally uses entropy optimization to compute 0N/A * usable tables for higher precision. If you don't want to do optimization, 0N/A * you'll have to supply different default Huffman tables. 0N/A * The exact same statements apply for progressive JPEG: the default tables 0N/A * don't work for progressive mode. (This may get fixed, however.) 0N/A/* Decoder capability options: */ 0N/A/* more capability options later, no doubt */ 0N/A * Ordering of RGB data in scanlines passed to or from the application. 0N/A * If your application wants to deal with data in the order B,G,R, just 0N/A * change these macros. You can also deal with formats such as R,G,B,X 0N/A * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing 0N/A * the offsets will also change the order in which colormap data is organized. 0N/A * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. 0N/A * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not 0N/A * useful if you are using JPEG color spaces other than YCbCr or grayscale. 0N/A * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE 0N/A * is not 3 (they don't understand about dummy color components!). So you 0N/A * can't use color quantization if you change that value. 0N/A#
define RGB_RED 0
/* Offset of Red in an RGB scanline element */ 0N/A/* Definitions for speed-related optimizations. */ 0N/A/* If your compiler supports inline functions, define INLINE 0N/A * as the inline keyword; otherwise define it as empty. 0N/A#
ifdef __GNUC__ /* for instance, GNU C knows about inline */ 0N/A#
define INLINE /* default is to define it as empty */ 0N/A/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying 0N/A * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER 0N/A * as short on such a machine. MULTIPLIER must be at least 16 bits wide. 0N/A/* FAST_FLOAT should be either float or double, whichever is done faster 0N/A * by your compiler. (Note that this type is only used in the floating point 0N/A * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) 0N/A * Typically, float is faster in ANSI C compilers, while double is faster in 0N/A * pre-ANSI compilers (because they insist on converting to double anyway). 0N/A * The code below therefore chooses float if we have ANSI-style prototypes. 0N/A#
endif /* JPEG_INTERNAL_OPTIONS */