1/*
2 * reserved comment block
3 * DO NOT REMOVE OR ALTER!
4 */
5/*
6 * jmorecfg.h
7 *
8 * Copyright (C) 1991-1997, Thomas G. Lane.
9 * This file is part of the Independent JPEG Group's software.
10 * For conditions of distribution and use, see the accompanying README file.
11 *
12 * This file contains additional configuration options that customize the
13 * JPEG software for special applications or support machine-dependent
14 * optimizations. Most users will not need to touch this file.
15 */
16
17
18/*
19 * Define BITS_IN_JSAMPLE as either
20 * 8 for 8-bit sample values (the usual setting)
21 * 12 for 12-bit sample values
22 * Only 8 and 12 are legal data precisions for lossy JPEG according to the
23 * JPEG standard, and the IJG code does not support anything else!
24 * We do not support run-time selection of data precision, sorry.
25 */
26
27#define BITS_IN_JSAMPLE 8 /* use 8 or 12 */
28
29
30/*
31 * Maximum number of components (color channels) allowed in JPEG image.
32 * To meet the letter of the JPEG spec, set this to 255. However, darn
33 * few applications need more than 4 channels (maybe 5 for CMYK + alpha
34 * mask). We recommend 10 as a reasonable compromise; use 4 if you are
35 * really short on memory. (Each allowed component costs a hundred or so
36 * bytes of storage, whether actually used in an image or not.)
37 */
38
39#define MAX_COMPONENTS 10 /* maximum number of image components */
40
41
42/*
43 * Basic data types.
44 * You may need to change these if you have a machine with unusual data
45 * type sizes; for example, "char" not 8 bits, "short" not 16 bits,
46 * or "long" not 32 bits. We don't care whether "int" is 16 or 32 bits,
47 * but it had better be at least 16.
48 */
49
50/* Representation of a single sample (pixel element value).
51 * We frequently allocate large arrays of these, so it's important to keep
52 * them small. But if you have memory to burn and access to char or short
53 * arrays is very slow on your hardware, you might want to change these.
54 */
55
56#if BITS_IN_JSAMPLE == 8
57/* JSAMPLE should be the smallest type that will hold the values 0..255.
58 * You can use a signed char by having GETJSAMPLE mask it with 0xFF.
59 */
60
61#ifdef HAVE_UNSIGNED_CHAR
62
63typedef unsigned char JSAMPLE;
64#define GETJSAMPLE(value) ((int) (value))
65
66#else /* not HAVE_UNSIGNED_CHAR */
67
68typedef char JSAMPLE;
69#ifdef CHAR_IS_UNSIGNED
70#define GETJSAMPLE(value) ((int) (value))
71#else
72#define GETJSAMPLE(value) ((int) (value) & 0xFF)
73#endif /* CHAR_IS_UNSIGNED */
74
75#endif /* HAVE_UNSIGNED_CHAR */
76
77#define MAXJSAMPLE 255
78#define CENTERJSAMPLE 128
79
80#endif /* BITS_IN_JSAMPLE == 8 */
81
82
83#if BITS_IN_JSAMPLE == 12
84/* JSAMPLE should be the smallest type that will hold the values 0..4095.
85 * On nearly all machines "short" will do nicely.
86 */
87
88typedef short JSAMPLE;
89#define GETJSAMPLE(value) ((int) (value))
90
91#define MAXJSAMPLE 4095
92#define CENTERJSAMPLE 2048
93
94#endif /* BITS_IN_JSAMPLE == 12 */
95
96
97/* Representation of a DCT frequency coefficient.
98 * This should be a signed value of at least 16 bits; "short" is usually OK.
99 * Again, we allocate large arrays of these, but you can change to int
100 * if you have memory to burn and "short" is really slow.
101 */
102
103typedef short JCOEF;
104
105
106/* Compressed datastreams are represented as arrays of JOCTET.
107 * These must be EXACTLY 8 bits wide, at least once they are written to
108 * external storage. Note that when using the stdio data source/destination
109 * managers, this is also the data type passed to fread/fwrite.
110 */
111
112#ifdef HAVE_UNSIGNED_CHAR
113
114typedef unsigned char JOCTET;
115#define GETJOCTET(value) (value)
116
117#else /* not HAVE_UNSIGNED_CHAR */
118
119typedef char JOCTET;
120#ifdef CHAR_IS_UNSIGNED
121#define GETJOCTET(value) (value)
122#else
123#define GETJOCTET(value) ((value) & 0xFF)
124#endif /* CHAR_IS_UNSIGNED */
125
126#endif /* HAVE_UNSIGNED_CHAR */
127
128
129/* These typedefs are used for various table entries and so forth.
130 * They must be at least as wide as specified; but making them too big
131 * won't cost a huge amount of memory, so we don't provide special
132 * extraction code like we did for JSAMPLE. (In other words, these
133 * typedefs live at a different point on the speed/space tradeoff curve.)
134 */
135
136/* UINT8 must hold at least the values 0..255. */
137
138#ifdef HAVE_UNSIGNED_CHAR
139typedef unsigned char UINT8;
140#else /* not HAVE_UNSIGNED_CHAR */
141#ifdef CHAR_IS_UNSIGNED
142typedef char UINT8;
143#else /* not CHAR_IS_UNSIGNED */
144typedef short UINT8;
145#endif /* CHAR_IS_UNSIGNED */
146#endif /* HAVE_UNSIGNED_CHAR */
147
148/* UINT16 must hold at least the values 0..65535. */
149
150#ifdef HAVE_UNSIGNED_SHORT
151typedef unsigned short UINT16;
152#else /* not HAVE_UNSIGNED_SHORT */
153typedef unsigned int UINT16;
154#endif /* HAVE_UNSIGNED_SHORT */
155
156/* INT16 must hold at least the values -32768..32767. */
157
158#ifndef XMD_H /* X11/xmd.h correctly defines INT16 */
159typedef short INT16;
160#endif
161
162/* INT32 must hold at least signed 32-bit values. */
163
164#ifndef XMD_H /* X11/xmd.h correctly defines INT32 */
165#if defined(_LP64) || defined(_WIN32) /* _WIN32 is on all windows platfroms (x86 and x64) */
166typedef int INT32;
167#else
168typedef long INT32;
169#endif
170#endif
171
172/* Datatype used for image dimensions. The JPEG standard only supports
173 * images up to 64K*64K due to 16-bit fields in SOF markers. Therefore
174 * "unsigned int" is sufficient on all machines. However, if you need to
175 * handle larger images and you don't mind deviating from the spec, you
176 * can change this datatype.
177 */
178
179typedef unsigned int JDIMENSION;
180
181#ifndef _LP64
182#define JPEG_MAX_DIMENSION 65500L /* a tad under 64K to prevent overflows */
183#else
184#define JPEG_MAX_DIMENSION 65500 /* a tad under 64K to prevent overflows */
185#endif
186
187
188/* These macros are used in all function definitions and extern declarations.
189 * You could modify them if you need to change function linkage conventions;
190 * in particular, you'll need to do that to make the library a Windows DLL.
191 * Another application is to make all functions global for use with debuggers
192 * or code profilers that require it.
193 */
194
195/* a function called through method pointers: */
196#define METHODDEF(type) static type
197/* a function used only in its module: */
198#define LOCAL(type) static type
199/* a function referenced thru EXTERNs: */
200#define GLOBAL(type) type
201/* a reference to a GLOBAL function: */
202#define EXTERN(type) extern type
203
204
205/* This macro is used to declare a "method", that is, a function pointer.
206 * We want to supply prototype parameters if the compiler can cope.
207 * Note that the arglist parameter must be parenthesized!
208 * Again, you can customize this if you need special linkage keywords.
209 */
210
211#ifdef HAVE_PROTOTYPES
212#define JMETHOD(type,methodname,arglist) type (*methodname) arglist
213#else
214#define JMETHOD(type,methodname,arglist) type (*methodname) ()
215#endif
216
217
218/* Here is the pseudo-keyword for declaring pointers that must be "far"
219 * on 80x86 machines. Most of the specialized coding for 80x86 is handled
220 * by just saying "FAR *" where such a pointer is needed. In a few places
221 * explicit coding is needed; see uses of the NEED_FAR_POINTERS symbol.
222 */
223
224
225#ifndef FAR
226#ifdef NEED_FAR_POINTERS
227#define FAR far
228#else
229#define FAR
230#endif
231#endif
232
233
234/*
235 * On a few systems, type boolean and/or its values FALSE, TRUE may appear
236 * in standard header files. Or you may have conflicts with application-
237 * specific header files that you want to include together with these files.
238 * Defining HAVE_BOOLEAN before including jpeglib.h should make it work.
239 */
240
241#ifndef HAVE_BOOLEAN
242typedef int boolean;
243#endif
244#ifndef FALSE /* in case these macros already exist */
245#define FALSE 0 /* values of boolean */
246#endif
247#ifndef TRUE
248#define TRUE 1
249#endif
250
251
252/*
253 * The remaining options affect code selection within the JPEG library,
254 * but they don't need to be visible to most applications using the library.
255 * To minimize application namespace pollution, the symbols won't be
256 * defined unless JPEG_INTERNALS or JPEG_INTERNAL_OPTIONS has been defined.
257 */
258
259#ifdef JPEG_INTERNALS
260#define JPEG_INTERNAL_OPTIONS
261#endif
262
263#ifdef JPEG_INTERNAL_OPTIONS
264
265
266/*
267 * These defines indicate whether to include various optional functions.
268 * Undefining some of these symbols will produce a smaller but less capable
269 * library. Note that you can leave certain source files out of the
270 * compilation/linking process if you've #undef'd the corresponding symbols.
271 * (You may HAVE to do that if your compiler doesn't like null source files.)
272 */
273
274/* Arithmetic coding is unsupported for legal reasons. Complaints to IBM. */
275
276/* Capability options common to encoder and decoder: */
277
278#define DCT_ISLOW_SUPPORTED /* slow but accurate integer algorithm */
279#define DCT_IFAST_SUPPORTED /* faster, less accurate integer method */
280#define DCT_FLOAT_SUPPORTED /* floating-point: accurate, fast on fast HW */
281
282/* Encoder capability options: */
283
284#undef C_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
285#define C_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
286#define C_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/
287#define ENTROPY_OPT_SUPPORTED /* Optimization of entropy coding parms? */
288/* Note: if you selected 12-bit data precision, it is dangerous to turn off
289 * ENTROPY_OPT_SUPPORTED. The standard Huffman tables are only good for 8-bit
290 * precision, so jchuff.c normally uses entropy optimization to compute
291 * usable tables for higher precision. If you don't want to do optimization,
292 * you'll have to supply different default Huffman tables.
293 * The exact same statements apply for progressive JPEG: the default tables
294 * don't work for progressive mode. (This may get fixed, however.)
295 */
296#define INPUT_SMOOTHING_SUPPORTED /* Input image smoothing option? */
297
298/* Decoder capability options: */
299
300#undef D_ARITH_CODING_SUPPORTED /* Arithmetic coding back end? */
301#define D_MULTISCAN_FILES_SUPPORTED /* Multiple-scan JPEG files? */
302#define D_PROGRESSIVE_SUPPORTED /* Progressive JPEG? (Requires MULTISCAN)*/
303#define SAVE_MARKERS_SUPPORTED /* jpeg_save_markers() needed? */
304#define BLOCK_SMOOTHING_SUPPORTED /* Block smoothing? (Progressive only) */
305#define IDCT_SCALING_SUPPORTED /* Output rescaling via IDCT? */
306#undef UPSAMPLE_SCALING_SUPPORTED /* Output rescaling at upsample stage? */
307#define UPSAMPLE_MERGING_SUPPORTED /* Fast path for sloppy upsampling? */
308#define QUANT_1PASS_SUPPORTED /* 1-pass color quantization? */
309#define QUANT_2PASS_SUPPORTED /* 2-pass color quantization? */
310
311/* more capability options later, no doubt */
312
313
314/*
315 * Ordering of RGB data in scanlines passed to or from the application.
316 * If your application wants to deal with data in the order B,G,R, just
317 * change these macros. You can also deal with formats such as R,G,B,X
318 * (one extra byte per pixel) by changing RGB_PIXELSIZE. Note that changing
319 * the offsets will also change the order in which colormap data is organized.
320 * RESTRICTIONS:
321 * 1. The sample applications cjpeg,djpeg do NOT support modified RGB formats.
322 * 2. These macros only affect RGB<=>YCbCr color conversion, so they are not
323 * useful if you are using JPEG color spaces other than YCbCr or grayscale.
324 * 3. The color quantizer modules will not behave desirably if RGB_PIXELSIZE
325 * is not 3 (they don't understand about dummy color components!). So you
326 * can't use color quantization if you change that value.
327 */
328
329#define RGB_RED 0 /* Offset of Red in an RGB scanline element */
330#define RGB_GREEN 1 /* Offset of Green */
331#define RGB_BLUE 2 /* Offset of Blue */
332#define RGB_PIXELSIZE 3 /* JSAMPLEs per RGB scanline element */
333
334
335/* Definitions for speed-related optimizations. */
336
337
338/* If your compiler supports inline functions, define INLINE
339 * as the inline keyword; otherwise define it as empty.
340 */
341
342#ifndef INLINE
343#ifdef __GNUC__ /* for instance, GNU C knows about inline */
344#define INLINE __inline__
345#endif
346#ifndef INLINE
347#define INLINE /* default is to define it as empty */
348#endif
349#endif
350
351
352/* On some machines (notably 68000 series) "int" is 32 bits, but multiplying
353 * two 16-bit shorts is faster than multiplying two ints. Define MULTIPLIER
354 * as short on such a machine. MULTIPLIER must be at least 16 bits wide.
355 */
356
357#ifndef MULTIPLIER
358#define MULTIPLIER int /* type for fastest integer multiply */
359#endif
360
361
362/* FAST_FLOAT should be either float or double, whichever is done faster
363 * by your compiler. (Note that this type is only used in the floating point
364 * DCT routines, so it only matters if you've defined DCT_FLOAT_SUPPORTED.)
365 * Typically, float is faster in ANSI C compilers, while double is faster in
366 * pre-ANSI compilers (because they insist on converting to double anyway).
367 * The code below therefore chooses float if we have ANSI-style prototypes.
368 */
369
370#ifndef FAST_FLOAT
371#ifdef HAVE_PROTOTYPES
372#define FAST_FLOAT float
373#else
374#define FAST_FLOAT double
375#endif
376#endif
377
378#endif /* JPEG_INTERNAL_OPTIONS */
379