source: trunk/libjpeg/jmorecfg.h @ 426

Last change on this file since 426 was 283, checked in by rbri, 12 years ago

JPEG plugin: libjpeg updated to version 7

File size: 12.7 KB
Line 
1/*
2 * jmorecfg.h
3 *
4 * Copyright (C) 1991-1997, Thomas G. Lane.
5 * Modified 1997-2009 by Guido Vollbeding.
6 * This file is part of the Independent JPEG Group's software.
7 * For conditions of distribution and use, see the accompanying README file.
8 *
9 * This file contains additional configuration options that customize the
10 * JPEG software for special applications or support machine-dependent
11 * optimizations.  Most users will not need to touch this file.
12 */
13
14
15/*
16 * Define BITS_IN_JSAMPLE as either
17 *   8   for 8-bit sample values (the usual setting)
18 *   12  for 12-bit sample values
19 * Only 8 and 12 are legal data precisions for lossy JPEG according to the
20 * JPEG standard, and the IJG code does not support anything else!
21 * We do not support run-time selection of data precision, sorry.
22 */
23
24#define BITS_IN_JSAMPLE  8      /* use 8 or 12 */
25
26
27/*
28 * Maximum number of components (color channels) allowed in JPEG image.
29 * To meet the letter of the JPEG spec, set this to 255.  However, darn
30 * few applications need more than 4 channels (maybe 5 for CMYK + alpha
31 * mask).  We recommend 10 as a reasonable compromise; use 4 if you are
32 * really short on memory.  (Each allowed component costs a hundred or so
33 * bytes of storage, whether actually used in an image or not.)
34 */
35
36#define MAX_COMPONENTS  10      /* maximum number of image components */
37
38
39/*
40 * Basic data types.
41 * You may need to change these if you have a machine with unusual data
42 * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
43 * or "long" not 32 bits.  We don't care whether "int" is 16 or 32 bits,
44 * but it had better be at least 16.
45 */
46
47/* Representation of a single sample (pixel element value).
48 * We frequently allocate large arrays of these, so it's important to keep
49 * them small.  But if you have memory to burn and access to char or short
50 * arrays is very slow on your hardware, you might want to change these.
51 */
52
53#if BITS_IN_JSAMPLE == 8
54/* JSAMPLE should be the smallest type that will hold the values 0..255.
55 * You can use a signed char by having GETJSAMPLE mask it with 0xFF.
56 */
57
58#ifdef HAVE_UNSIGNED_CHAR
59
60typedef unsigned char JSAMPLE;
61#define GETJSAMPLE(value)  ((int) (value))
62
63#else /* not HAVE_UNSIGNED_CHAR */
64
65typedef char JSAMPLE;
66#ifdef CHAR_IS_UNSIGNED
67#define GETJSAMPLE(value)  ((int) (value))
68#else
69#define GETJSAMPLE(value)  ((int) (value) & 0xFF)
70#endif /* CHAR_IS_UNSIGNED */
71
72#endif /* HAVE_UNSIGNED_CHAR */
73
74#define MAXJSAMPLE      255
75#define CENTERJSAMPLE   128
76
77#endif /* BITS_IN_JSAMPLE == 8 */
78
79
80#if BITS_IN_JSAMPLE == 12
81/* JSAMPLE should be the smallest type that will hold the values 0..4095.
82 * On nearly all machines "short" will do nicely.
83 */
84
85typedef short JSAMPLE;
86#define GETJSAMPLE(value)  ((int) (value))
87
88#define MAXJSAMPLE      4095
89#define CENTERJSAMPLE   2048
90
91#endif /* BITS_IN_JSAMPLE == 12 */
92
93
94/* Representation of a DCT frequency coefficient.
95 * This should be a signed value of at least 16 bits; "short" is usually OK.
96 * Again, we allocate large arrays of these, but you can change to int
97 * if you have memory to burn and "short" is really slow.
98 */
99
100typedef short JCOEF;
101
102
103/* Compressed datastreams are represented as arrays of JOCTET.
104 * These must be EXACTLY 8 bits wide, at least once they are written to
105 * external storage.  Note that when using the stdio data source/destination
106 * managers, this is also the data type passed to fread/fwrite.
107 */
108
109#ifdef HAVE_UNSIGNED_CHAR
110
111typedef unsigned char JOCTET;
112#define GETJOCTET(value)  (value)
113
114#else /* not HAVE_UNSIGNED_CHAR */
115
116typedef char JOCTET;
117#ifdef CHAR_IS_UNSIGNED
118#define GETJOCTET(value)  (value)
119#else
120#define GETJOCTET(value)  ((value) & 0xFF)
121#endif /* CHAR_IS_UNSIGNED */
122
123#endif /* HAVE_UNSIGNED_CHAR */
124
125
126/* These typedefs are used for various table entries and so forth.
127 * They must be at least as wide as specified; but making them too big
128 * won't cost a huge amount of memory, so we don't provide special
129 * extraction code like we did for JSAMPLE.  (In other words, these
130 * typedefs live at a different point on the speed/space tradeoff curve.)
131 */
132
133/* UINT8 must hold at least the values 0..255. */
134
135#ifdef HAVE_UNSIGNED_CHAR
136typedef unsigned char UINT8;
137#else /* not HAVE_UNSIGNED_CHAR */
138#ifdef CHAR_IS_UNSIGNED
139typedef char UINT8;
140#else /* not CHAR_IS_UNSIGNED */
141typedef short UINT8;
142#endif /* CHAR_IS_UNSIGNED */
143#endif /* HAVE_UNSIGNED_CHAR */
144
145/* UINT16 must hold at least the values 0..65535. */
146
147#ifdef HAVE_UNSIGNED_SHORT
148typedef unsigned short UINT16;
149#else /* not HAVE_UNSIGNED_SHORT */
150typedef unsigned int UINT16;
151#endif /* HAVE_UNSIGNED_SHORT */
152
153/* INT16 must hold at least the values -32768..32767. */
154
155#ifndef XMD_H                   /* X11/xmd.h correctly defines INT16 */
156typedef short INT16;
157#endif
158
159/* INT32 must hold at least signed 32-bit values. */
160
161#ifndef XMD_H                   /* X11/xmd.h correctly defines INT32 */
162#ifndef _BASETSD_H_             /* Microsoft defines it in basetsd.h */
163#ifndef QGLOBAL_H               /* Qt defines it in qglobal.h */
164typedef long INT32;
165#endif
166#endif
167#endif
168
169/* Datatype used for image dimensions.  The JPEG standard only supports
170 * images up to 64K*64K due to 16-bit fields in SOF markers.  Therefore
171 * "unsigned int" is sufficient on all machines.  However, if you need to
172 * handle larger images and you don't mind deviating from the spec, you
173 * can change this datatype.
174 */
175
176typedef unsigned int JDIMENSION;
177
178#define JPEG_MAX_DIMENSION  65500L  /* a tad under 64K to prevent overflows */
179
180
181/* These macros are used in all function definitions and extern declarations.
182 * You could modify them if you need to change function linkage conventions;
183 * in particular, you'll need to do that to make the library a Windows DLL.
184 * Another application is to make all functions global for use with debuggers
185 * or code profilers that require it.
186 */
187
188/* a function called through method pointers: */
189#define METHODDEF(type)         static type
190/* a function used only in its module: */
191#define LOCAL(type)             static type
192/* a function referenced thru EXTERNs: */
193#define GLOBAL(type)            type
194/* a reference to a GLOBAL function: */
195#define EXTERN(type)            extern type
196
197
198/* This macro is used to declare a "method", that is, a function pointer.
199 * We want to supply prototype parameters if the compiler can cope.
200 * Note that the arglist parameter must be parenthesized!
201 * Again, you can customize this if you need special linkage keywords.
202 */
203
204#ifdef HAVE_PROTOTYPES
205#define JMETHOD(type,methodname,arglist)  type (*methodname) arglist
206#else
207#define JMETHOD(type,methodname,arglist)  type (*methodname) ()
208#endif
209
210
211/* Here is the pseudo-keyword for declaring pointers that must be "far"
212 * on 80x86 machines.  Most of the specialized coding for 80x86 is handled
213 * by just saying "FAR *" where such a pointer is needed.  In a few places
214 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
215 */
216
217#ifndef FAR
218#ifdef NEED_FAR_POINTERS
219#define FAR  far
220#else
221#define FAR
222#endif
223#endif
224
225
226/*
227 * On a few systems, type boolean and/or its values FALSE, TRUE may appear
228 * in standard header files.  Or you may have conflicts with application-
229 * specific header files that you want to include together with these files.
230 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
231 */
232
233#ifndef HAVE_BOOLEAN
234typedef int boolean;
235#endif
236#ifndef FALSE                   /* in case these macros already exist */
237#define FALSE   0               /* values of boolean */
238#endif
239#ifndef TRUE
240#define TRUE    1
241#endif
242
243
244/*
245 * The remaining options affect code selection within the JPEG library,
246 * but they don't need to be visible to most applications using the library.
247 * To minimize application namespace pollution, the symbols won't be
248 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
249 */
250
251#ifdef JPEG_INTERNALS
252#define JPEG_INTERNAL_OPTIONS
253#endif
254
255#ifdef JPEG_INTERNAL_OPTIONS
256
257
258/*
259 * These defines indicate whether to include various optional functions.
260 * Undefining some of these symbols will produce a smaller but less capable
261 * library.  Note that you can leave certain source files out of the
262 * compilation/linking process if you've #undef'd the corresponding symbols.
263 * (You may HAVE to do that if your compiler doesn't like null source files.)
264 */
265
266/* Capability options common to encoder and decoder: */
267
268#define DCT_ISLOW_SUPPORTED     /* slow but accurate integer algorithm */
269#define DCT_IFAST_SUPPORTED     /* faster, less accurate integer method */
270#define DCT_FLOAT_SUPPORTED     /* floating-point: accurate, fast on fast HW */
271
272/* Encoder capability options: */
273
274#define C_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
275#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
276#define C_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
277#define DCT_SCALING_SUPPORTED       /* Input rescaling via DCT? (Requires DCT_ISLOW)*/
278#define ENTROPY_OPT_SUPPORTED       /* Optimization of entropy coding parms? */
279/* Note: if you selected 12-bit data precision, it is dangerous to turn off
280 * ENTROPY_OPT_SUPPORTED.  The standard Huffman tables are only good for 8-bit
281 * precision, so jchuff.c normally uses entropy optimization to compute
282 * usable tables for higher precision.  If you don't want to do optimization,
283 * you'll have to supply different default Huffman tables.
284 * The exact same statements apply for progressive JPEG: the default tables
285 * don't work for progressive mode.  (This may get fixed, however.)
286 */
287#define INPUT_SMOOTHING_SUPPORTED   /* Input image smoothing option? */
288
289/* Decoder capability options: */
290
291#define D_ARITH_CODING_SUPPORTED    /* Arithmetic coding back end? */
292#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
293#define D_PROGRESSIVE_SUPPORTED     /* Progressive JPEG? (Requires MULTISCAN)*/
294#define IDCT_SCALING_SUPPORTED      /* Output rescaling via IDCT? */
295#define SAVE_MARKERS_SUPPORTED      /* jpeg_save_markers() needed? */
296#define BLOCK_SMOOTHING_SUPPORTED   /* Block smoothing? (Progressive only) */
297#undef  UPSAMPLE_SCALING_SUPPORTED  /* Output rescaling at upsample stage? */
298#define UPSAMPLE_MERGING_SUPPORTED  /* Fast path for sloppy upsampling? */
299#define QUANT_1PASS_SUPPORTED       /* 1-pass color quantization? */
300#define QUANT_2PASS_SUPPORTED       /* 2-pass color quantization? */
301
302/* more capability options later, no doubt */
303
304
305/*
306 * Ordering of RGB data in scanlines passed to or from the application.
307 * If your application wants to deal with data in the order B,G,R, just
308 * change these macros.  You can also deal with formats such as R,G,B,X
309 * (one extra byte per pixel) by changing RGB_PIXELSIZE.  Note that changing
310 * the offsets will also change the order in which colormap data is organized.
311 * RESTRICTIONS:
312 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
313 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
314 *    useful if you are using JPEG color spaces other than YCbCr or grayscale.
315 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
316 *    is not 3 (they don't understand about dummy color components!).  So you
317 *    can't use color quantization if you change that value.
318 */
319
320#define RGB_RED         0       /* Offset of Red in an RGB scanline element */
321#define RGB_GREEN       1       /* Offset of Green */
322#define RGB_BLUE        2       /* Offset of Blue */
323#define RGB_PIXELSIZE   3       /* JSAMPLEs per RGB scanline element */
324
325
326/* Definitions for speed-related optimizations. */
327
328
329/* If your compiler supports inline functions, define INLINE
330 * as the inline keyword; otherwise define it as empty.
331 */
332
333#ifndef INLINE
334#ifdef __GNUC__                 /* for instance, GNU C knows about inline */
335#define INLINE __inline__
336#endif
337#ifndef INLINE
338#define INLINE                  /* default is to define it as empty */
339#endif
340#endif
341
342
343/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
344 * two 16-bit shorts is faster than multiplying two ints.  Define MULTIPLIER
345 * as short on such a machine.  MULTIPLIER must be at least 16 bits wide.
346 */
347
348#ifndef MULTIPLIER
349#define MULTIPLIER  int         /* type for fastest integer multiply */
350#endif
351
352
353/* FAST_FLOAT should be either float or double, whichever is done faster
354 * by your compiler.  (Note that this type is only used in the floating point
355 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
356 * Typically, float is faster in ANSI C compilers, while double is faster in
357 * pre-ANSI compilers (because they insist on converting to double anyway).
358 * The code below therefore chooses float if we have ANSI-style prototypes.
359 */
360
361#ifndef FAST_FLOAT
362#ifdef HAVE_PROTOTYPES
363#define FAST_FLOAT  float
364#else
365#define FAST_FLOAT  double
366#endif
367#endif
368
369#endif /* JPEG_INTERNAL_OPTIONS */
Note: See TracBrowser for help on using the repository browser.