nuclear@2: /* nuclear@2: * jmorecfg.h nuclear@2: * nuclear@2: * Copyright (C) 1991-1997, Thomas G. Lane. nuclear@2: * This file is part of the Independent JPEG Group's software. nuclear@2: * For conditions of distribution and use, see the accompanying README file. nuclear@2: * nuclear@2: * This file contains additional configuration options that customize the nuclear@2: * JPEG software for special applications or support machine-dependent nuclear@2: * optimizations. Most users will not need to touch this file. nuclear@2: */ nuclear@2: nuclear@2: nuclear@2: /* nuclear@2: * Define BITS_IN_JSAMPLE as either nuclear@2: * 8 for 8-bit sample values (the usual setting) nuclear@2: * 12 for 12-bit sample values nuclear@2: * Only 8 and 12 are legal data precisions for lossy JPEG according to the nuclear@2: * JPEG standard, and the IJG code does not support anything else! nuclear@2: * We do not support run-time selection of data precision, sorry. nuclear@2: */ nuclear@2: nuclear@2: #define BITS_IN_JSAMPLE 8 /* use 8 or 12 */ nuclear@2: nuclear@2: nuclear@2: /* nuclear@2: * Maximum number of components (color channels) allowed in JPEG image. nuclear@2: * To meet the letter of the JPEG spec, set this to 255. However, darn nuclear@2: * few applications need more than 4 channels (maybe 5 for CMYK + alpha nuclear@2: * mask). We recommend 10 as a reasonable compromise; use 4 if you are nuclear@2: * really short on memory. (Each allowed component costs a hundred or so nuclear@2: * bytes of storage, whether actually used in an image or not.) nuclear@2: */ nuclear@2: nuclear@2: #define MAX_COMPONENTS 10 /* maximum number of image components */ nuclear@2: nuclear@2: nuclear@2: /* nuclear@2: * Basic data types. nuclear@2: * You may need to change these if you have a machine with unusual data nuclear@2: * type sizes; for example, "char" not 8 bits, "short" not 16 bits, nuclear@2: * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits, nuclear@2: * but it had better be at least 16. nuclear@2: */ nuclear@2: nuclear@2: /* Representation of a single sample (pixel element value). nuclear@2: * We frequently allocate large arrays of these, so it's important to keep nuclear@2: * them small. But if you have memory to burn and access to char or short nuclear@2: * arrays is very slow on your hardware, you might want to change these. nuclear@2: */ nuclear@2: nuclear@2: #if BITS_IN_JSAMPLE == 8 nuclear@2: /* JSAMPLE should be the smallest type that will hold the values 0..255. nuclear@2: * You can use a signed char by having GETJSAMPLE mask it with 0xFF. nuclear@2: */ nuclear@2: nuclear@2: #ifdef HAVE_UNSIGNED_CHAR nuclear@2: nuclear@2: typedef unsigned char JSAMPLE; nuclear@2: #define GETJSAMPLE(value) ((int) (value)) nuclear@2: nuclear@2: #else /* not HAVE_UNSIGNED_CHAR */ nuclear@2: nuclear@2: typedef char JSAMPLE; nuclear@2: #ifdef CHAR_IS_UNSIGNED nuclear@2: #define GETJSAMPLE(value) ((int) (value)) nuclear@2: #else nuclear@2: #define GETJSAMPLE(value) ((int) (value) & 0xFF) nuclear@2: #endif /* CHAR_IS_UNSIGNED */ nuclear@2: nuclear@2: #endif /* HAVE_UNSIGNED_CHAR */ nuclear@2: nuclear@2: #define MAXJSAMPLE 255 nuclear@2: #define CENTERJSAMPLE 128 nuclear@2: nuclear@2: #endif /* BITS_IN_JSAMPLE == 8 */ nuclear@2: nuclear@2: nuclear@2: #if BITS_IN_JSAMPLE == 12 nuclear@2: /* JSAMPLE should be the smallest type that will hold the values 0..4095. nuclear@2: * On nearly all machines "short" will do nicely. nuclear@2: */ nuclear@2: nuclear@2: typedef short JSAMPLE; nuclear@2: #define GETJSAMPLE(value) ((int) (value)) nuclear@2: nuclear@2: #define MAXJSAMPLE 4095 nuclear@2: #define CENTERJSAMPLE 2048 nuclear@2: nuclear@2: #endif /* BITS_IN_JSAMPLE == 12 */ nuclear@2: nuclear@2: nuclear@2: /* Representation of a DCT frequency coefficient. nuclear@2: * This should be a signed value of at least 16 bits; "short" is usually OK. nuclear@2: * Again, we allocate large arrays of these, but you can change to int nuclear@2: * if you have memory to burn and "short" is really slow. nuclear@2: */ nuclear@2: nuclear@2: typedef short JCOEF; nuclear@2: nuclear@2: nuclear@2: /* Compressed datastreams are represented as arrays of JOCTET. nuclear@2: * These must be EXACTLY 8 bits wide, at least once they are written to nuclear@2: * external storage. Note that when using the stdio data source/destination nuclear@2: * managers, this is also the data type passed to fread/fwrite. nuclear@2: */ nuclear@2: nuclear@2: #ifdef HAVE_UNSIGNED_CHAR nuclear@2: nuclear@2: typedef unsigned char JOCTET; nuclear@2: #define GETJOCTET(value) (value) nuclear@2: nuclear@2: #else /* not HAVE_UNSIGNED_CHAR */ nuclear@2: nuclear@2: typedef char JOCTET; nuclear@2: #ifdef CHAR_IS_UNSIGNED nuclear@2: #define GETJOCTET(value) (value) nuclear@2: #else nuclear@2: #define GETJOCTET(value) ((value) & 0xFF) nuclear@2: #endif /* CHAR_IS_UNSIGNED */ nuclear@2: nuclear@2: #endif /* HAVE_UNSIGNED_CHAR */ nuclear@2: nuclear@2: nuclear@2: /* These typedefs are used for various table entries and so forth. nuclear@2: * They must be at least as wide as specified; but making them too big nuclear@2: * won't cost a huge amount of memory, so we don't provide special nuclear@2: * extraction code like we did for JSAMPLE. (In other words, these nuclear@2: * typedefs live at a different point on the speed/space tradeoff curve.) nuclear@2: */ nuclear@2: nuclear@2: /* UINT8 must hold at least the values 0..255. */ nuclear@2: nuclear@2: #ifdef HAVE_UNSIGNED_CHAR nuclear@2: typedef unsigned char UINT8; nuclear@2: #else /* not HAVE_UNSIGNED_CHAR */ nuclear@2: #ifdef CHAR_IS_UNSIGNED nuclear@2: typedef char UINT8; nuclear@2: #else /* not CHAR_IS_UNSIGNED */ nuclear@2: typedef short UINT8; nuclear@2: #endif /* CHAR_IS_UNSIGNED */ nuclear@2: #endif /* HAVE_UNSIGNED_CHAR */ nuclear@2: nuclear@2: /* UINT16 must hold at least the values 0..65535. */ nuclear@2: nuclear@2: #ifdef HAVE_UNSIGNED_SHORT nuclear@2: typedef unsigned short UINT16; nuclear@2: #else /* not HAVE_UNSIGNED_SHORT */ nuclear@2: typedef unsigned int UINT16; nuclear@2: #endif /* HAVE_UNSIGNED_SHORT */ nuclear@2: nuclear@2: /* INT16 must hold at least the values -32768..32767. */ nuclear@2: nuclear@2: #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */ nuclear@2: typedef short INT16; nuclear@2: #endif nuclear@2: nuclear@2: /* INT32 must hold at least signed 32-bit values. */ nuclear@2: nuclear@2: #ifndef XMD_H /* X11/xmd.h correctly defines INT32 */ nuclear@2: typedef int INT32; nuclear@2: #endif nuclear@2: nuclear@2: /* Datatype used for image dimensions. The JPEG standard only supports nuclear@2: * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore nuclear@2: * "unsigned int" is sufficient on all machines. However, if you need to nuclear@2: * handle larger images and you don't mind deviating from the spec, you nuclear@2: * can change this datatype. nuclear@2: */ nuclear@2: nuclear@2: typedef unsigned int JDIMENSION; nuclear@2: nuclear@2: #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ nuclear@2: nuclear@2: nuclear@2: /* These macros are used in all function definitions and extern declarations. nuclear@2: * You could modify them if you need to change function linkage conventions; nuclear@2: * in particular, you'll need to do that to make the library a Windows DLL. nuclear@2: * Another application is to make all functions global for use with debuggers nuclear@2: * or code profilers that require it. nuclear@2: */ nuclear@2: nuclear@2: /* a function called through method pointers: */ nuclear@2: #define METHODDEF(type) static type nuclear@2: /* a function used only in its module: */ nuclear@2: #define LOCAL(type) static type nuclear@2: /* a function referenced thru EXTERNs: */ nuclear@2: #define GLOBAL(type) type nuclear@2: /* a reference to a GLOBAL function: */ nuclear@2: #define EXTERN(type) extern type nuclear@2: nuclear@2: nuclear@2: /* This macro is used to declare a "method", that is, a function pointer. nuclear@2: * We want to supply prototype parameters if the compiler can cope. nuclear@2: * Note that the arglist parameter must be parenthesized! nuclear@2: * Again, you can customize this if you need special linkage keywords. nuclear@2: */ nuclear@2: nuclear@2: #ifdef HAVE_PROTOTYPES nuclear@2: #define JMETHOD(type,methodname,arglist) type (*methodname) arglist nuclear@2: #else nuclear@2: #define JMETHOD(type,methodname,arglist) type (*methodname) () nuclear@2: #endif nuclear@2: nuclear@2: nuclear@2: /* Here is the pseudo-keyword for declaring pointers that must be "far" nuclear@2: * on 80x86 machines. Most of the specialized coding for 80x86 is handled nuclear@2: * by just saying "FAR *" where such a pointer is needed. In a few places nuclear@2: * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. nuclear@2: */ nuclear@2: nuclear@2: #ifdef FAR nuclear@2: #undef FAR nuclear@2: #endif nuclear@2: nuclear@2: #ifdef NEED_FAR_POINTERS nuclear@2: #define FAR far nuclear@2: #else nuclear@2: #define FAR nuclear@2: #endif nuclear@2: nuclear@2: nuclear@2: /* nuclear@2: * On a few systems, type boolean and/or its values FALSE, TRUE may appear nuclear@2: * in standard header files. Or you may have conflicts with application- nuclear@2: * specific header files that you want to include together with these files. nuclear@2: * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. nuclear@2: */ nuclear@2: nuclear@2: #ifndef HAVE_BOOLEAN nuclear@2: typedef int boolean; nuclear@2: #endif nuclear@2: #ifndef FALSE /* in case these macros already exist */ nuclear@2: #define FALSE 0 /* values of boolean */ nuclear@2: #endif nuclear@2: #ifndef TRUE nuclear@2: #define TRUE 1 nuclear@2: #endif nuclear@2: nuclear@2: nuclear@2: /* nuclear@2: * The remaining options affect code selection within the JPEG library, nuclear@2: * but they don't need to be visible to most applications using the library. nuclear@2: * To minimize application namespace pollution, the symbols won't be nuclear@2: * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. nuclear@2: */ nuclear@2: nuclear@2: #ifdef JPEG_INTERNALS nuclear@2: #define JPEG_INTERNAL_OPTIONS nuclear@2: #endif nuclear@2: nuclear@2: #ifdef JPEG_INTERNAL_OPTIONS nuclear@2: nuclear@2: nuclear@2: /* nuclear@2: * These defines indicate whether to include various optional functions. nuclear@2: * Undefining some of these symbols will produce a smaller but less capable nuclear@2: * library. Note that you can leave certain source files out of the nuclear@2: * compilation/linking process if you've #undef'd the corresponding symbols. nuclear@2: * (You may HAVE to do that if your compiler doesn't like null source files.) nuclear@2: */ nuclear@2: nuclear@2: /* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */ nuclear@2: nuclear@2: /* Capability options common to encoder and decoder: */ nuclear@2: nuclear@2: #define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */ nuclear@2: #define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */ nuclear@2: #define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */ nuclear@2: nuclear@2: /* Encoder capability options: */ nuclear@2: nuclear@2: #undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ nuclear@2: #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ nuclear@2: #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ nuclear@2: #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */ nuclear@2: /* Note: if you selected 12-bit data precision, it is dangerous to turn off nuclear@2: * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit nuclear@2: * precision, so jchuff.c normally uses entropy optimization to compute nuclear@2: * usable tables for higher precision. If you don't want to do optimization, nuclear@2: * you'll have to supply different default Huffman tables. nuclear@2: * The exact same statements apply for progressive JPEG: the default tables nuclear@2: * don't work for progressive mode. (This may get fixed, however.) nuclear@2: */ nuclear@2: #define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ nuclear@2: nuclear@2: /* Decoder capability options: */ nuclear@2: nuclear@2: #undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */ nuclear@2: #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ nuclear@2: #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ nuclear@2: #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ nuclear@2: #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ nuclear@2: #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ nuclear@2: #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ nuclear@2: #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ nuclear@2: #define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ nuclear@2: #define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ nuclear@2: nuclear@2: /* more capability options later, no doubt */ nuclear@2: nuclear@2: nuclear@2: /* nuclear@2: * Ordering of RGB data in scanlines passed to or from the application. nuclear@2: * If your application wants to deal with data in the order B,G,R, just nuclear@2: * change these macros. You can also deal with formats such as R,G,B,X nuclear@2: * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing nuclear@2: * the offsets will also change the order in which colormap data is organized. nuclear@2: * RESTRICTIONS: nuclear@2: * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats. nuclear@2: * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not nuclear@2: * useful if you are using JPEG color spaces other than YCbCr or grayscale. nuclear@2: * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE nuclear@2: * is not 3 (they don't understand about dummy color components!). So you nuclear@2: * can't use color quantization if you change that value. nuclear@2: */ nuclear@2: nuclear@2: #define RGB_RED 0 /* Offset of Red in an RGB scanline element */ nuclear@2: #define RGB_GREEN 1 /* Offset of Green */ nuclear@2: #define RGB_BLUE 2 /* Offset of Blue */ nuclear@2: #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ nuclear@2: nuclear@2: nuclear@2: /* Definitions for speed-related optimizations. */ nuclear@2: nuclear@2: nuclear@2: /* If your compiler supports inline functions, define INLINE nuclear@2: * as the inline keyword; otherwise define it as empty. nuclear@2: */ nuclear@2: nuclear@2: #ifndef INLINE nuclear@2: #ifdef __GNUC__ /* for instance, GNU C knows about inline */ nuclear@2: #define INLINE __inline__ nuclear@2: #endif nuclear@2: #ifndef INLINE nuclear@2: #define INLINE /* default is to define it as empty */ nuclear@2: #endif nuclear@2: #endif nuclear@2: nuclear@2: nuclear@2: /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying nuclear@2: * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER nuclear@2: * as short on such a machine. MULTIPLIER must be at least 16 bits wide. nuclear@2: */ nuclear@2: nuclear@2: #ifndef MULTIPLIER nuclear@2: #define MULTIPLIER int /* type for fastest integer multiply */ nuclear@2: #endif nuclear@2: nuclear@2: nuclear@2: /* FAST_FLOAT should be either float or double, whichever is done faster nuclear@2: * by your compiler. (Note that this type is only used in the floating point nuclear@2: * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) nuclear@2: * Typically, float is faster in ANSI C compilers, while double is faster in nuclear@2: * pre-ANSI compilers (because they insist on converting to double anyway). nuclear@2: * The code below therefore chooses float if we have ANSI-style prototypes. nuclear@2: */ nuclear@2: nuclear@2: #ifndef FAST_FLOAT nuclear@2: #ifdef HAVE_PROTOTYPES nuclear@2: #define FAST_FLOAT float nuclear@2: #else nuclear@2: #define FAST_FLOAT double nuclear@2: #endif nuclear@2: #endif nuclear@2: nuclear@2: #endif /* JPEG_INTERNAL_OPTIONS */