/* * jmorecfg.h * * Copyright (C) 1991-1994, Thomas G. Lane. * This file is part of the Independent JPEG Group's software. * For conditions of distribution and use, see the accompanying README file. * * This file contains additional configuration options that customize the * JPEG software for special applications or support machine-dependent * optimizations.  Most users will not need to touch this file. *//* * Define BITS_IN_JSAMPLE as either *   8   for 8-bit sample values (the usual setting) *   12  for 12-bit sample values * Only 8 and 12 are legal data precisions for lossy JPEG according to the * JPEG standard, and the IJG code does not support anything else! * We do not support run-time selection of data precision, sorry. */#define BITS_IN_JSAMPLE  8	/* use 8 or 12 *//* * Maximum number of components (color channels) allowed in JPEG image. * To meet the letter of the JPEG spec, set this to 255.  However, darn * few applications need more than 4 channels (maybe 5 for CMYK + alpha * mask).  We recommend 10 as a reasonable compromise; use 4 if you are * really short on memory.  (Each allowed component costs a hundred or so * bytes of storage, whether actually used in an image or not.) */#define MAX_COMPONENTS  10	/* maximum number of image components *//* * Basic data types. * You may need to change these if you have a machine with unusual data * type sizes; for example, "char" not 8 bits, "short" not 16 bits, * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits, * but it had better be at least 16. *//* Representation of a single sample (pixel element value). * We frequently allocate large arrays of these, so it's important to keep * them small.  But if you have memory to burn and access to char or short * arrays is very slow on your hardware, you might want to change these. */#if BITS_IN_JSAMPLE == 8/* JSAMPLE should be the smallest type that will hold the values 0..255. * You can use a signed char by having GETJSAMPLE mask it with 0xFF. */#ifdef HAVE_UNSIGNED_CHARtypedef unsigned char JSAMPLE;#define GETJSAMPLE(value)  (value)#else /* not HAVE_UNSIGNED_CHAR */typedef char JSAMPLE;#ifdef CHAR_IS_UNSIGNED#define GETJSAMPLE(value)  (value)#else#define GETJSAMPLE(value)  ((value) & 0xFF)#endif /* CHAR_IS_UNSIGNED */#endif /* HAVE_UNSIGNED_CHAR */#define MAXJSAMPLE	255#define CENTERJSAMPLE	128#endif /* BITS_IN_JSAMPLE == 8 */#if BITS_IN_JSAMPLE == 12/* JSAMPLE should be the smallest type that will hold the values 0..4095. * On nearly all machines "short" will do nicely. */typedef short JSAMPLE;#define GETJSAMPLE(value)  (value)#define MAXJSAMPLE	4095#define CENTERJSAMPLE	2048#endif /* BITS_IN_JSAMPLE == 12 *//* Representation of a DCT frequency coefficient. * This should be a signed value of at least 16 bits; "short" is usually OK. * Again, we allocate large arrays of these, but you can change to int * if you have memory to burn and "short" is really slow. */typedef short JCOEF;/* Compressed datastreams are represented as arrays of JOCTET. * These must be EXACTLY 8 bits wide, at least once they are written to * external storage.  Note that when using the stdio data source/destination * managers, this is also the data type passed to fread/fwrite. */#ifdef HAVE_UNSIGNED_CHARtypedef unsigned char JOCTET;#define GETJOCTET(value)  (value)#else /* not HAVE_UNSIGNED_CHAR */typedef char JOCTET;#ifdef CHAR_IS_UNSIGNED#define GETJOCTET(value)  (value)#else#define GETJOCTET(value)  ((value) & 0xFF)#endif /* CHAR_IS_UNSIGNED */#endif /* HAVE_UNSIGNED_CHAR *//* These typedefs are used for various table entries and so forth. * They must be at least as wide as specified; but making them too big * won't cost a huge amount of memory, so we don't provide special * extraction code like we did for JSAMPLE.  (In other words, these * typedefs live at a different point on the speed/space tradeoff curve.) *//* UINT8 must hold at least the values 0..255. */#ifdef HAVE_UNSIGNED_CHARtypedef unsigned char UINT8;#else /* not HAVE_UNSIGNED_CHAR */#ifdef CHAR_IS_UNSIGNEDtypedef char UINT8;#else /* not CHAR_IS_UNSIGNED */typedef short UINT8;#endif /* CHAR_IS_UNSIGNED */#endif /* HAVE_UNSIGNED_CHAR *//* UINT16 must hold at least the values 0..65535. */#ifdef HAVE_UNSIGNED_SHORTtypedef unsigned short UINT16;#else /* not HAVE_UNSIGNED_SHORT */typedef unsigned int UINT16;#endif /* HAVE_UNSIGNED_SHORT *//* INT16 must hold at least the values -32768..32767. */#ifndef XMD_H			/* X11/xmd.h correctly defines INT16 */typedef short INT16;#endif/* INT32 must hold at least signed 32-bit values. */#ifndef XMD_H			/* X11/xmd.h correctly defines INT32 */typedef long INT32;#endif/* Datatype used for image dimensions.  The JPEG standard only supports * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore * "unsigned int" is sufficient on all machines.  However, if you need to * handle larger images and you don't mind deviating from the spec, you * can change this datatype. */typedef unsigned int JDIMENSION;#define JPEG_MAX_DIMENSION  65500 /* a tad under 64K to prevent overflows *//* These defines are used in all function definitions and extern declarations. * You could modify them if you need to change function linkage conventions. * Another application is to make all functions global for use with debuggers * or code profilers that require it. */#define METHODDEF static	/* a function called through method pointers */#define LOCAL	  static	/* a function used only in its module */#define GLOBAL			/* a function referenced thru EXTERNs */#define EXTERN	  extern	/* a reference to a GLOBAL function *//* Here is the pseudo-keyword for declaring pointers that must be "far" * on 80x86 machines.  Most of the specialized coding for 80x86 is handled * by just saying "FAR *" where such a pointer is needed.  In a few places * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol. */#ifdef NEED_FAR_POINTERS#define FAR  far#else#define FAR#endif/* * On a few systems, type boolean and/or its values FALSE, TRUE may appear * in standard header files.  Or you may have conflicts with application- * specific header files that you want to include together with these files. * In that case you need only comment out these definitions. */#ifndef BOOLEAN_DEFINEDtypedef int boolean;#endif#ifndef FALSE			/* in case these macros already exist */#define FALSE	0		/* values of boolean */#endif#ifndef TRUE#define TRUE	1#endif/* * The following options affect code selection within the JPEG library, * but they don't need to be visible to applications using the library. * To minimize application namespace pollution, the symbols won't be * defined unless JPEG_INTERNALS has been defined. */#ifdef JPEG_INTERNALS/* * These defines indicate whether to include various optional functions. * Undefining some of these symbols will produce a smaller but less capable * library.  Note that you can leave certain source files out of the * compilation/linking process if you've #undef'd the corresponding symbols. * (You may HAVE to do that if your compiler doesn't like null source files.) *//* Arithmetic coding is unsupported for legal reasons.  Complaints to IBM. *//* Encoder capability options: */#undef  C_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */#undef  C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files?  (NYI) */#define ENTROPY_OPT_SUPPORTED	    /* Optimization of entropy coding parms? *//* Note: if you selected 12-bit data precision, it is dangerous to turn off * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit * precision, so jchuff.c normally uses entropy optimization to compute * usable tables for higher precision.  If you don't want to do optimization, * you'll have to supply different default Huffman tables. */#define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? *//* Decoder capability options: */#undef  D_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */#define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing during decoding? */#define QUANT_1PASS_SUPPORTED	    /* 1-pass color quantization? */#define QUANT_2PASS_SUPPORTED	    /* 2-pass color quantization? *//* more capability options later, no doubt *//* If your compiler supports inline functions, define INLINE * as the inline keyword; otherwise define it as empty. */#ifdef __GNUC__			/* for instance, GNU C knows about inline */#define INLINE __inline__#endif#ifndef INLINE			/* default is to define it as empty */#define INLINE#endif/* Typedef for multiplying quantized coefficients by pre-IDCT multipliers. * Must be a signed type.  Use short if short*short is faster than int*int. */#if BITS_IN_JSAMPLE == 8typedef int MULTIPLIER;		/* may want short on some machines */#elsetypedef INT32 MULTIPLIER;	/* need more than 16 bits in this case */#endif#endif /* JPEG_INTERNALS */