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Edit File: jmorecfg.h
/* * jmorecfg.h * * This file was part of the Independent JPEG Group's software: * Copyright (C) 1991-1997, Thomas G. Lane. * Modified 1997-2009 by Guido Vollbeding. * libjpeg-turbo Modifications: * Copyright (C) 2009, 2011, 2014-2015, 2018, 2020, D. R. Commander. * For conditions of distribution and use, see the accompanying README.ijg * 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. */ /* * Maximum number of components (color channels) allowed in JPEG image. * To meet the letter of Rec. ITU-T T.81 | ISO/IEC 10918-1, 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. */ typedef unsigned char JSAMPLE; #define GETJSAMPLE(value) ((int)(value)) #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) ((int)(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. */ typedef unsigned char JOCTET; #define GETJOCTET(value) (value) /* 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. */ typedef unsigned char UINT8; /* UINT16 must hold at least the values 0..65535. */ #ifdef HAVE_UNSIGNED_SHORT typedef 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. * * NOTE: The INT32 typedef dates back to libjpeg v5 (1994.) Integers were * sometimes 16-bit back then (MS-DOS), which is why INT32 is typedef'd to * long. It also wasn't common (or at least as common) in 1994 for INT32 to be * defined by platform headers. Since then, however, INT32 is defined in * several other common places: * * Xmd.h (X11 header) typedefs INT32 to int on 64-bit platforms and long on * 32-bit platforms (i.e always a 32-bit signed type.) * * basetsd.h (Win32 header) typedefs INT32 to int (always a 32-bit signed type * on modern platforms.) * * qglobal.h (Qt header) typedefs INT32 to int (always a 32-bit signed type on * modern platforms.) * * This is a recipe for conflict, since "long" and "int" aren't always * compatible types. Since the definition of INT32 has technically been part * of the libjpeg API for more than 20 years, we can't remove it, but we do not * use it internally any longer. We instead define a separate type (JLONG) * for internal use, which ensures that internal behavior will always be the * same regardless of any external headers that may be included. */ #ifndef XMD_H /* X11/xmd.h correctly defines INT32 */ #ifndef _BASETSD_H_ /* Microsoft defines it in basetsd.h */ #ifndef _BASETSD_H /* MinGW is slightly different */ #ifndef QGLOBAL_H /* Qt defines it in qglobal.h */ typedef long INT32; #endif #endif #endif #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. (Note that changing this datatype will * potentially require modifying the SIMD code. The x86-64 SIMD extensions, * in particular, assume a 32-bit JDIMENSION.) */ typedef unsigned int JDIMENSION; #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */ /* These macros are used in all function definitions and extern declarations. * You could modify them if you need to change function linkage conventions; * in particular, you'll need to do that to make the library a Windows DLL. * Another application is to make all functions global for use with debuggers * or code profilers that require it. */ /* a function called through method pointers: */ #define METHODDEF(type) static type /* a function used only in its module: */ #define LOCAL(type) static type /* a function referenced thru EXTERNs: */ #define GLOBAL(type) type /* a reference to a GLOBAL function: */ #define EXTERN(type) extern type /* Originally, this macro was used as a way of defining function prototypes * for both modern compilers as well as older compilers that did not support * prototype parameters. libjpeg-turbo has never supported these older, * non-ANSI compilers, but the macro is still included because there is some * software out there that uses it. */ #define JMETHOD(type, methodname, arglist) type (*methodname) arglist /* libjpeg-turbo no longer supports platforms that have far symbols (MS-DOS), * but again, some software relies on this macro. */ #undef FAR #define FAR /* * 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. * Defining HAVE_BOOLEAN before including jpeglib.h should make it work. */ #ifndef HAVE_BOOLEAN typedef 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 remaining options affect code selection within the JPEG library, * but they don't need to be visible to most applications using the library. * To minimize application namespace pollution, the symbols won't be * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined. */ #ifdef JPEG_INTERNALS #define JPEG_INTERNAL_OPTIONS #endif #ifdef JPEG_INTERNAL_OPTIONS /* * 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.) */ /* Capability options common to encoder and decoder: */ #define DCT_ISLOW_SUPPORTED /* accurate integer method */ #define DCT_IFAST_SUPPORTED /* less accurate int method [legacy feature] */ #define DCT_FLOAT_SUPPORTED /* floating-point method [legacy feature] */ /* Encoder capability options: */ #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ #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. * The exact same statements apply for progressive JPEG: the default tables * don't work for progressive mode. (This may get fixed, however.) */ #define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */ /* Decoder capability options: */ #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */ #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/ #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */ #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */ #define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */ #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */ #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */ #define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */ #define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */ /* more capability options later, no doubt */ /* * The RGB_RED, RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE macros are a vestigial * feature of libjpeg. The idea was that, if an application developer needed * to compress from/decompress to a BGR/BGRX/RGBX/XBGR/XRGB buffer, they could * change these macros, rebuild libjpeg, and link their application statically * with it. In reality, few people ever did this, because there were some * severe restrictions involved (cjpeg and djpeg no longer worked properly, * compressing/decompressing RGB JPEGs no longer worked properly, and the color * quantizer wouldn't work with pixel sizes other than 3.) Furthermore, since * all of the O/S-supplied versions of libjpeg were built with the default * values of RGB_RED, RGB_GREEN, RGB_BLUE, and RGB_PIXELSIZE, many applications * have come to regard these values as immutable. * * The libjpeg-turbo colorspace extensions provide a much cleaner way of * compressing from/decompressing to buffers with arbitrary component orders * and pixel sizes. Thus, we do not support changing the values of RGB_RED, * RGB_GREEN, RGB_BLUE, or RGB_PIXELSIZE. In addition to the restrictions * listed above, changing these values will also break the SIMD extensions and * the regression tests. */ #define RGB_RED 0 /* Offset of Red in an RGB scanline element */ #define RGB_GREEN 1 /* Offset of Green */ #define RGB_BLUE 2 /* Offset of Blue */ #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */ #define JPEG_NUMCS 17 #define EXT_RGB_RED 0 #define EXT_RGB_GREEN 1 #define EXT_RGB_BLUE 2 #define EXT_RGB_PIXELSIZE 3 #define EXT_RGBX_RED 0 #define EXT_RGBX_GREEN 1 #define EXT_RGBX_BLUE 2 #define EXT_RGBX_PIXELSIZE 4 #define EXT_BGR_RED 2 #define EXT_BGR_GREEN 1 #define EXT_BGR_BLUE 0 #define EXT_BGR_PIXELSIZE 3 #define EXT_BGRX_RED 2 #define EXT_BGRX_GREEN 1 #define EXT_BGRX_BLUE 0 #define EXT_BGRX_PIXELSIZE 4 #define EXT_XBGR_RED 3 #define EXT_XBGR_GREEN 2 #define EXT_XBGR_BLUE 1 #define EXT_XBGR_PIXELSIZE 4 #define EXT_XRGB_RED 1 #define EXT_XRGB_GREEN 2 #define EXT_XRGB_BLUE 3 #define EXT_XRGB_PIXELSIZE 4 static const int rgb_red[JPEG_NUMCS] = { -1, -1, RGB_RED, -1, -1, -1, EXT_RGB_RED, EXT_RGBX_RED, EXT_BGR_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED, EXT_RGBX_RED, EXT_BGRX_RED, EXT_XBGR_RED, EXT_XRGB_RED, -1 }; static const int rgb_green[JPEG_NUMCS] = { -1, -1, RGB_GREEN, -1, -1, -1, EXT_RGB_GREEN, EXT_RGBX_GREEN, EXT_BGR_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN, EXT_RGBX_GREEN, EXT_BGRX_GREEN, EXT_XBGR_GREEN, EXT_XRGB_GREEN, -1 }; static const int rgb_blue[JPEG_NUMCS] = { -1, -1, RGB_BLUE, -1, -1, -1, EXT_RGB_BLUE, EXT_RGBX_BLUE, EXT_BGR_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE, EXT_RGBX_BLUE, EXT_BGRX_BLUE, EXT_XBGR_BLUE, EXT_XRGB_BLUE, -1 }; static const int rgb_pixelsize[JPEG_NUMCS] = { -1, -1, RGB_PIXELSIZE, -1, -1, -1, EXT_RGB_PIXELSIZE, EXT_RGBX_PIXELSIZE, EXT_BGR_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE, EXT_RGBX_PIXELSIZE, EXT_BGRX_PIXELSIZE, EXT_XBGR_PIXELSIZE, EXT_XRGB_PIXELSIZE, -1 }; /* Definitions for speed-related optimizations. */ /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER * as short on such a machine. MULTIPLIER must be at least 16 bits wide. */ #ifndef MULTIPLIER #ifndef WITH_SIMD #define MULTIPLIER int /* type for fastest integer multiply */ #else #define MULTIPLIER short /* prefer 16-bit with SIMD for parellelism */ #endif #endif /* FAST_FLOAT should be either float or double, whichever is done faster * by your compiler. (Note that this type is only used in the floating point * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.) */ #ifndef FAST_FLOAT #define FAST_FLOAT float #endif #endif /* JPEG_INTERNAL_OPTIONS */