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[chromium-blink-merge.git] / third_party / libjpeg / jmorecfg.h
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1 /*
2 * jmorecfg.h
4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * This file is part of the Independent JPEG Group's software.
6 * For conditions of distribution and use, see the accompanying README file.
8 * This file contains additional configuration options that customize the
9 * JPEG software for special applications or support machine-dependent
10 * optimizations. Most users will not need to touch this file.
14 * This file has been modified for the Mozilla/Netscape environment.
15 * Modifications are distributed under the Netscape Public License and are
16 * Copyright (C) 1998 Netscape Communications Corporation. All Rights
17 * Reserved.
22 * Define BITS_IN_JSAMPLE as either
23 * 8 for 8-bit sample values (the usual setting)
24 * 12 for 12-bit sample values
25 * Only 8 and 12 are legal data precisions for lossy JPEG according to the
26 * JPEG standard, and the IJG code does not support anything else!
27 * We do not support run-time selection of data precision, sorry.
30 #define BITS_IN_JSAMPLE 8 /* use 8 or 12 */
34 * Maximum number of components (color channels) allowed in JPEG image.
35 * To meet the letter of the JPEG spec, set this to 255. However, darn
36 * few applications need more than 4 channels (maybe 5 for CMYK + alpha
37 * mask). We recommend 10 as a reasonable compromise; use 4 if you are
38 * really short on memory. (Each allowed component costs a hundred or so
39 * bytes of storage, whether actually used in an image or not.)
42 #define MAX_COMPONENTS 10 /* maximum number of image components */
46 * Basic data types.
47 * You may need to change these if you have a machine with unusual data
48 * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
49 * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits,
50 * but it had better be at least 16.
53 /* Representation of a single sample (pixel element value).
54 * We frequently allocate large arrays of these, so it's important to keep
55 * them small. But if you have memory to burn and access to char or short
56 * arrays is very slow on your hardware, you might want to change these.
59 #if BITS_IN_JSAMPLE == 8
60 /* JSAMPLE should be the smallest type that will hold the values 0..255.
61 * You can use a signed char by having GETJSAMPLE mask it with 0xFF.
64 #ifdef HAVE_UNSIGNED_CHAR
66 typedef unsigned char JSAMPLE;
67 #define GETJSAMPLE(value) ((int) (value))
69 #else /* not HAVE_UNSIGNED_CHAR */
71 typedef char JSAMPLE;
72 #ifdef CHAR_IS_UNSIGNED
73 #define GETJSAMPLE(value) ((int) (value))
74 #else
75 #define GETJSAMPLE(value) ((int) (value) & 0xFF)
76 #endif /* CHAR_IS_UNSIGNED */
78 #endif /* HAVE_UNSIGNED_CHAR */
80 #define MAXJSAMPLE 255
81 #define CENTERJSAMPLE 128
83 #endif /* BITS_IN_JSAMPLE == 8 */
86 #if BITS_IN_JSAMPLE == 12
87 /* JSAMPLE should be the smallest type that will hold the values 0..4095.
88 * On nearly all machines "short" will do nicely.
91 typedef short JSAMPLE;
92 #define GETJSAMPLE(value) ((int) (value))
94 #define MAXJSAMPLE 4095
95 #define CENTERJSAMPLE 2048
97 #endif /* BITS_IN_JSAMPLE == 12 */
100 /* Representation of a DCT frequency coefficient.
101 * This should be a signed value of at least 16 bits; "short" is usually OK.
102 * Again, we allocate large arrays of these, but you can change to int
103 * if you have memory to burn and "short" is really slow.
106 typedef short JCOEF;
108 /* Defines for MMX/SSE2 support. */
110 #if defined(XP_WIN32) && defined(_M_IX86) && !defined(__GNUC__)
111 #define HAVE_MMX_INTEL_MNEMONICS
113 /* SSE2 code appears broken for some cpus (bug 247437) */
114 /* #define HAVE_SSE2_INTEL_MNEMONICS */
115 #endif
117 /* Compressed datastreams are represented as arrays of JOCTET.
118 * These must be EXACTLY 8 bits wide, at least once they are written to
119 * external storage. Note that when using the stdio data source/destination
120 * managers, this is also the data type passed to fread/fwrite.
123 #ifdef HAVE_UNSIGNED_CHAR
125 typedef unsigned char JOCTET;
126 #define GETJOCTET(value) (value)
128 #else /* not HAVE_UNSIGNED_CHAR */
130 typedef char JOCTET;
131 #ifdef CHAR_IS_UNSIGNED
132 #define GETJOCTET(value) (value)
133 #else
134 #define GETJOCTET(value) ((value) & 0xFF)
135 #endif /* CHAR_IS_UNSIGNED */
137 #endif /* HAVE_UNSIGNED_CHAR */
140 /* These typedefs are used for various table entries and so forth.
141 * They must be at least as wide as specified; but making them too big
142 * won't cost a huge amount of memory, so we don't provide special
143 * extraction code like we did for JSAMPLE. (In other words, these
144 * typedefs live at a different point on the speed/space tradeoff curve.)
147 /* UINT8 must hold at least the values 0..255. */
149 #ifdef HAVE_UNSIGNED_CHAR
150 typedef unsigned char UINT8;
151 #else /* not HAVE_UNSIGNED_CHAR */
152 #ifdef CHAR_IS_UNSIGNED
153 typedef char UINT8;
154 #else /* not CHAR_IS_UNSIGNED */
155 typedef short UINT8;
156 #endif /* CHAR_IS_UNSIGNED */
157 #endif /* HAVE_UNSIGNED_CHAR */
159 /* UINT16 must hold at least the values 0..65535. */
161 #ifdef HAVE_UNSIGNED_SHORT
162 typedef unsigned short UINT16;
163 #else /* not HAVE_UNSIGNED_SHORT */
164 typedef unsigned int UINT16;
165 #endif /* HAVE_UNSIGNED_SHORT */
167 /* INT16 must hold at least the values -32768..32767. */
169 #ifndef XMD_H /* X11/xmd.h correctly defines INT16 */
170 typedef short INT16;
171 #endif
173 /* INT32 must hold at least signed 32-bit values. */
175 #ifndef XMD_H /* X11/xmd.h correctly defines INT32 */
176 #ifndef _BASETSD_H_ /* basetsd.h correctly defines INT32 */
177 #ifndef _BASETSD_H
178 typedef long INT32;
179 #endif
180 #endif
181 #endif
183 /* Datatype used for image dimensions. The JPEG standard only supports
184 * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore
185 * "unsigned int" is sufficient on all machines. However, if you need to
186 * handle larger images and you don't mind deviating from the spec, you
187 * can change this datatype.
190 typedef unsigned int JDIMENSION;
192 #define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */
195 /* These macros are used in all function definitions and extern declarations.
196 * You could modify them if you need to change function linkage conventions;
197 * in particular, you'll need to do that to make the library a Windows DLL.
198 * Another application is to make all functions global for use with debuggers
199 * or code profilers that require it.
202 /* a function called through method pointers: */
203 #define METHODDEF(type) static type
204 /* a function used only in its module: */
205 #define LOCAL(type) static type
206 /* a function referenced thru EXTERNs: */
207 #define GLOBAL(type) type
208 /* a reference to a GLOBAL function: */
209 #define EXTERN(type) extern type
212 /* This macro is used to declare a "method", that is, a function pointer.
213 * We want to supply prototype parameters if the compiler can cope.
214 * Note that the arglist parameter must be parenthesized!
215 * Again, you can customize this if you need special linkage keywords.
218 #ifdef HAVE_PROTOTYPES
219 #define JMETHOD(type,methodname,arglist) type (*methodname) arglist
220 #else
221 #define JMETHOD(type,methodname,arglist) type (*methodname) ()
222 #endif
225 /* Here is the pseudo-keyword for declaring pointers that must be "far"
226 * on 80x86 machines. Most of the specialized coding for 80x86 is handled
227 * by just saying "FAR *" where such a pointer is needed. In a few places
228 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
231 #ifndef FAR
232 #ifdef NEED_FAR_POINTERS
233 #define FAR far
234 #else
235 #define FAR
236 #endif
237 #endif
241 * On a few systems, type boolean and/or its values FALSE, TRUE may appear
242 * in standard header files. Or you may have conflicts with application-
243 * specific header files that you want to include together with these files.
244 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
247 /* Mozilla mod: IJG distribution makes boolean = int, but on Windows
248 * it's far safer to define boolean = unsigned char. Easier to switch
249 * than fight.
252 /* For some reason, on SunOS 5.3 HAVE_BOOLEAN gets defined when using
253 * gcc, but boolean doesn't. Even if you use -UHAVE_BOOLEAN, it still
254 * gets reset somewhere.
256 #if defined(MUST_UNDEF_HAVE_BOOLEAN_AFTER_INCLUDES) && defined(HAVE_BOOLEAN)
257 #undef HAVE_BOOLEAN
258 #endif
259 #ifndef HAVE_BOOLEAN
260 typedef unsigned char boolean;
261 #endif
262 #ifndef FALSE /* in case these macros already exist */
263 #define FALSE 0 /* values of boolean */
264 #endif
265 #ifndef TRUE
266 #define TRUE 1
267 #endif
271 * The remaining options affect code selection within the JPEG library,
272 * but they don't need to be visible to most applications using the library.
273 * To minimize application namespace pollution, the symbols won't be
274 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
277 #ifdef JPEG_INTERNALS
278 #define JPEG_INTERNAL_OPTIONS
279 #endif
281 #ifdef JPEG_INTERNAL_OPTIONS
285 * These defines indicate whether to include various optional functions.
286 * Undefining some of these symbols will produce a smaller but less capable
287 * library. Note that you can leave certain source files out of the
288 * compilation/linking process if you've #undef'd the corresponding symbols.
289 * (You may HAVE to do that if your compiler doesn't like null source files.)
293 * Mozilla mods here: undef some features not actually used by the browser.
294 * This reduces object code size and more importantly allows us to compile
295 * even with broken compilers that crash when fed certain modules of the
296 * IJG sources. Currently we undef:
297 * DCT_FLOAT_SUPPORTED INPUT_SMOOTHING_SUPPORTED IDCT_SCALING_SUPPORTED
298 * QUANT_1PASS_SUPPORTED QUANT_2PASS_SUPPORTED
301 /* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */
303 /* Capability options common to encoder and decoder: */
305 #define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */
306 #undef DCT_IFAST_SUPPORTED /* faster, less accurate integer method */
307 #undef DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */
309 /* Encoder capability options: */
311 #undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
312 #define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
313 #define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/
314 #define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */
315 /* Note: if you selected 12-bit data precision, it is dangerous to turn off
316 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit
317 * precision, so jchuff.c normally uses entropy optimization to compute
318 * usable tables for higher precision. If you don't want to do optimization,
319 * you'll have to supply different default Huffman tables.
320 * The exact same statements apply for progressive JPEG: the default tables
321 * don't work for progressive mode. (This may get fixed, however.)
323 #undef INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */
325 /* TextResourceDecoder capability options: */
327 #undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
328 #define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
329 #define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/
330 #define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */
331 #define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */
332 #undef IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */
333 #undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */
334 #define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */
335 #undef QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */
336 #undef QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */
338 /* more capability options later, no doubt */
342 * Ordering of RGB data in scanlines passed to or from the application.
343 * If your application wants to deal with data in the order B,G,R, just
344 * change these macros. You can also deal with formats such as R,G,B,X
345 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing
346 * the offsets will also change the order in which colormap data is organized.
347 * RESTRICTIONS:
348 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
349 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
350 * useful if you are using JPEG color spaces other than YCbCr or grayscale.
351 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
352 * is not 3 (they don't understand about dummy color components!). So you
353 * can't use color quantization if you change that value.
356 #define RGB_RED 0 /* Offset of Red in an RGB scanline element */
357 #define RGB_GREEN 1 /* Offset of Green */
358 #define RGB_BLUE 2 /* Offset of Blue */
359 #define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */
362 /* Definitions for speed-related optimizations. */
365 /* If your compiler supports inline functions, define INLINE
366 * as the inline keyword; otherwise define it as empty.
369 /* Mozilla mods here: add more ways of defining INLINE */
371 #ifndef INLINE
372 #ifdef __GNUC__ /* for instance, GNU C knows about inline */
373 #define INLINE __inline__
374 #endif
375 #if defined( __IBMC__ ) || defined (__IBMCPP__)
376 #define INLINE _Inline
377 #endif
378 #ifndef INLINE
379 #ifdef __cplusplus
380 #define INLINE inline /* a C++ compiler should have it too */
381 #else
382 #define INLINE /* default is to define it as empty */
383 #endif
384 #endif
385 #endif
388 /* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
389 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER
390 * as short on such a machine. MULTIPLIER must be at least 16 bits wide.
393 #ifndef MULTIPLIER
394 #define MULTIPLIER int /* type for fastest integer multiply */
395 #endif
398 /* FAST_FLOAT should be either float or double, whichever is done faster
399 * by your compiler. (Note that this type is only used in the floating point
400 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
401 * Typically, float is faster in ANSI C compilers, while double is faster in
402 * pre-ANSI compilers (because they insist on converting to double anyway).
403 * The code below therefore chooses float if we have ANSI-style prototypes.
406 #ifndef FAST_FLOAT
407 #ifdef HAVE_PROTOTYPES
408 #define FAST_FLOAT float
409 #else
410 #define FAST_FLOAT double
411 #endif
412 #endif
414 #endif /* JPEG_INTERNAL_OPTIONS */