ReactOS 0.4.15-dev-7906-g1b85a5f
jdct.h
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1/*
2 * jdct.h
3 *
4 * Copyright (C) 1994-1996, Thomas G. Lane.
5 * Modified 2002-2019 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 include file contains common declarations for the forward and
10 * inverse DCT modules. These declarations are private to the DCT managers
11 * (jcdctmgr.c, jddctmgr.c) and the individual DCT algorithms.
12 * The individual DCT algorithms are kept in separate files to ease
13 * machine-dependent tuning (e.g., assembly coding).
14 */
15
16
17/*
18 * A forward DCT routine is given a pointer to an input sample array and
19 * a pointer to a work area of type DCTELEM[]; the DCT is to be performed
20 * in-place in that buffer. Type DCTELEM is int for 8-bit samples, INT32
21 * for 12-bit samples. (NOTE: Floating-point DCT implementations use an
22 * array of type FAST_FLOAT, instead.)
23 * The input data is to be fetched from the sample array starting at a
24 * specified column. (Any row offset needed will be applied to the array
25 * pointer before it is passed to the FDCT code.)
26 * Note that the number of samples fetched by the FDCT routine is
27 * DCT_h_scaled_size * DCT_v_scaled_size.
28 * The DCT outputs are returned scaled up by a factor of 8; they therefore
29 * have a range of +-8K for 8-bit data, +-128K for 12-bit data. This
30 * convention improves accuracy in integer implementations and saves some
31 * work in floating-point ones.
32 * Quantization of the output coefficients is done by jcdctmgr.c.
33 */
34
35#if BITS_IN_JSAMPLE == 8
36typedef int DCTELEM; /* 16 or 32 bits is fine */
37#else
38typedef INT32 DCTELEM; /* must have 32 bits */
39#endif
40
41typedef JMETHOD(void, forward_DCT_method_ptr, (DCTELEM * data,
44typedef JMETHOD(void, float_DCT_method_ptr, (FAST_FLOAT * data,
47
48
49/*
50 * An inverse DCT routine is given a pointer to the input JBLOCK and a pointer
51 * to an output sample array. The routine must dequantize the input data as
52 * well as perform the IDCT; for dequantization, it uses the multiplier table
53 * pointed to by compptr->dct_table. The output data is to be placed into the
54 * sample array starting at a specified column. (Any row offset needed will
55 * be applied to the array pointer before it is passed to the IDCT code.)
56 * Note that the number of samples emitted by the IDCT routine is
57 * DCT_h_scaled_size * DCT_v_scaled_size.
58 */
59
60/* typedef inverse_DCT_method_ptr is declared in jpegint.h */
61
62/*
63 * Each IDCT routine has its own ideas about the best dct_table element type.
64 */
65
66typedef MULTIPLIER ISLOW_MULT_TYPE; /* short or int, whichever is faster */
67#if BITS_IN_JSAMPLE == 8
68typedef MULTIPLIER IFAST_MULT_TYPE; /* 16 bits is OK, use short if faster */
69#define IFAST_SCALE_BITS 2 /* fractional bits in scale factors */
70#else
71typedef INT32 IFAST_MULT_TYPE; /* need 32 bits for scaled quantizers */
72#define IFAST_SCALE_BITS 13 /* fractional bits in scale factors */
73#endif
74typedef FAST_FLOAT FLOAT_MULT_TYPE; /* preferred floating type */
75
76
77/*
78 * Each IDCT routine is responsible for range-limiting its results and
79 * converting them to unsigned form (0..MAXJSAMPLE). The raw outputs could
80 * be quite far out of range if the input data is corrupt, so a bulletproof
81 * range-limiting step is required. We use a mask-and-table-lookup method
82 * to do the combined operations quickly, assuming that RANGE_CENTER
83 * (defined in jpegint.h) is a power of 2. See the comments with
84 * prepare_range_limit_table (in jdmaster.c) for more info.
85 */
86
87#define RANGE_MASK (RANGE_CENTER * 2 - 1)
88#define RANGE_SUBSET (RANGE_CENTER - CENTERJSAMPLE)
89
90#define IDCT_range_limit(cinfo) ((cinfo)->sample_range_limit - RANGE_SUBSET)
91
92
93/* Short forms of external names for systems with brain-damaged linkers. */
94
95#ifdef NEED_SHORT_EXTERNAL_NAMES
96#define jpeg_fdct_islow jFDislow
97#define jpeg_fdct_ifast jFDifast
98#define jpeg_fdct_float jFDfloat
99#define jpeg_fdct_7x7 jFD7x7
100#define jpeg_fdct_6x6 jFD6x6
101#define jpeg_fdct_5x5 jFD5x5
102#define jpeg_fdct_4x4 jFD4x4
103#define jpeg_fdct_3x3 jFD3x3
104#define jpeg_fdct_2x2 jFD2x2
105#define jpeg_fdct_1x1 jFD1x1
106#define jpeg_fdct_9x9 jFD9x9
107#define jpeg_fdct_10x10 jFD10x10
108#define jpeg_fdct_11x11 jFD11x11
109#define jpeg_fdct_12x12 jFD12x12
110#define jpeg_fdct_13x13 jFD13x13
111#define jpeg_fdct_14x14 jFD14x14
112#define jpeg_fdct_15x15 jFD15x15
113#define jpeg_fdct_16x16 jFD16x16
114#define jpeg_fdct_16x8 jFD16x8
115#define jpeg_fdct_14x7 jFD14x7
116#define jpeg_fdct_12x6 jFD12x6
117#define jpeg_fdct_10x5 jFD10x5
118#define jpeg_fdct_8x4 jFD8x4
119#define jpeg_fdct_6x3 jFD6x3
120#define jpeg_fdct_4x2 jFD4x2
121#define jpeg_fdct_2x1 jFD2x1
122#define jpeg_fdct_8x16 jFD8x16
123#define jpeg_fdct_7x14 jFD7x14
124#define jpeg_fdct_6x12 jFD6x12
125#define jpeg_fdct_5x10 jFD5x10
126#define jpeg_fdct_4x8 jFD4x8
127#define jpeg_fdct_3x6 jFD3x6
128#define jpeg_fdct_2x4 jFD2x4
129#define jpeg_fdct_1x2 jFD1x2
130#define jpeg_idct_islow jRDislow
131#define jpeg_idct_ifast jRDifast
132#define jpeg_idct_float jRDfloat
133#define jpeg_idct_7x7 jRD7x7
134#define jpeg_idct_6x6 jRD6x6
135#define jpeg_idct_5x5 jRD5x5
136#define jpeg_idct_4x4 jRD4x4
137#define jpeg_idct_3x3 jRD3x3
138#define jpeg_idct_2x2 jRD2x2
139#define jpeg_idct_1x1 jRD1x1
140#define jpeg_idct_9x9 jRD9x9
141#define jpeg_idct_10x10 jRD10x10
142#define jpeg_idct_11x11 jRD11x11
143#define jpeg_idct_12x12 jRD12x12
144#define jpeg_idct_13x13 jRD13x13
145#define jpeg_idct_14x14 jRD14x14
146#define jpeg_idct_15x15 jRD15x15
147#define jpeg_idct_16x16 jRD16x16
148#define jpeg_idct_16x8 jRD16x8
149#define jpeg_idct_14x7 jRD14x7
150#define jpeg_idct_12x6 jRD12x6
151#define jpeg_idct_10x5 jRD10x5
152#define jpeg_idct_8x4 jRD8x4
153#define jpeg_idct_6x3 jRD6x3
154#define jpeg_idct_4x2 jRD4x2
155#define jpeg_idct_2x1 jRD2x1
156#define jpeg_idct_8x16 jRD8x16
157#define jpeg_idct_7x14 jRD7x14
158#define jpeg_idct_6x12 jRD6x12
159#define jpeg_idct_5x10 jRD5x10
160#define jpeg_idct_4x8 jRD4x8
161#define jpeg_idct_3x6 jRD3x8
162#define jpeg_idct_2x4 jRD2x4
163#define jpeg_idct_1x2 jRD1x2
164#endif /* NEED_SHORT_EXTERNAL_NAMES */
165
166/* Extern declarations for the forward and inverse DCT routines. */
167
168EXTERN(void) jpeg_fdct_islow
170EXTERN(void) jpeg_fdct_ifast
172EXTERN(void) jpeg_fdct_float
174EXTERN(void) jpeg_fdct_7x7
176EXTERN(void) jpeg_fdct_6x6
178EXTERN(void) jpeg_fdct_5x5
180EXTERN(void) jpeg_fdct_4x4
182EXTERN(void) jpeg_fdct_3x3
184EXTERN(void) jpeg_fdct_2x2
186EXTERN(void) jpeg_fdct_1x1
188EXTERN(void) jpeg_fdct_9x9
190EXTERN(void) jpeg_fdct_10x10
192EXTERN(void) jpeg_fdct_11x11
194EXTERN(void) jpeg_fdct_12x12
196EXTERN(void) jpeg_fdct_13x13
198EXTERN(void) jpeg_fdct_14x14
200EXTERN(void) jpeg_fdct_15x15
202EXTERN(void) jpeg_fdct_16x16
204EXTERN(void) jpeg_fdct_16x8
206EXTERN(void) jpeg_fdct_14x7
208EXTERN(void) jpeg_fdct_12x6
210EXTERN(void) jpeg_fdct_10x5
212EXTERN(void) jpeg_fdct_8x4
214EXTERN(void) jpeg_fdct_6x3
216EXTERN(void) jpeg_fdct_4x2
218EXTERN(void) jpeg_fdct_2x1
220EXTERN(void) jpeg_fdct_8x16
222EXTERN(void) jpeg_fdct_7x14
224EXTERN(void) jpeg_fdct_6x12
226EXTERN(void) jpeg_fdct_5x10
228EXTERN(void) jpeg_fdct_4x8
230EXTERN(void) jpeg_fdct_3x6
232EXTERN(void) jpeg_fdct_2x4
234EXTERN(void) jpeg_fdct_1x2
236
237EXTERN(void) jpeg_idct_islow
240EXTERN(void) jpeg_idct_ifast
243EXTERN(void) jpeg_idct_float
246EXTERN(void) jpeg_idct_7x7
249EXTERN(void) jpeg_idct_6x6
252EXTERN(void) jpeg_idct_5x5
255EXTERN(void) jpeg_idct_4x4
258EXTERN(void) jpeg_idct_3x3
261EXTERN(void) jpeg_idct_2x2
264EXTERN(void) jpeg_idct_1x1
267EXTERN(void) jpeg_idct_9x9
270EXTERN(void) jpeg_idct_10x10
273EXTERN(void) jpeg_idct_11x11
276EXTERN(void) jpeg_idct_12x12
279EXTERN(void) jpeg_idct_13x13
282EXTERN(void) jpeg_idct_14x14
285EXTERN(void) jpeg_idct_15x15
288EXTERN(void) jpeg_idct_16x16
291EXTERN(void) jpeg_idct_16x8
294EXTERN(void) jpeg_idct_14x7
297EXTERN(void) jpeg_idct_12x6
300EXTERN(void) jpeg_idct_10x5
303EXTERN(void) jpeg_idct_8x4
306EXTERN(void) jpeg_idct_6x3
309EXTERN(void) jpeg_idct_4x2
312EXTERN(void) jpeg_idct_2x1
315EXTERN(void) jpeg_idct_8x16
318EXTERN(void) jpeg_idct_7x14
321EXTERN(void) jpeg_idct_6x12
324EXTERN(void) jpeg_idct_5x10
327EXTERN(void) jpeg_idct_4x8
330EXTERN(void) jpeg_idct_3x6
333EXTERN(void) jpeg_idct_2x4
336EXTERN(void) jpeg_idct_1x2
339
340
341/*
342 * Macros for handling fixed-point arithmetic; these are used by many
343 * but not all of the DCT/IDCT modules.
344 *
345 * All values are expected to be of type INT32.
346 * Fractional constants are scaled left by CONST_BITS bits.
347 * CONST_BITS is defined within each module using these macros,
348 * and may differ from one module to the next.
349 */
350
351#define ONE ((INT32) 1)
352#define CONST_SCALE (ONE << CONST_BITS)
353
354/* Convert a positive real constant to an integer scaled by CONST_SCALE.
355 * Caution: some C compilers fail to reduce "FIX(constant)" at compile time,
356 * thus causing a lot of useless floating-point operations at run time.
357 */
358
359#define FIX(x) ((INT32) ((x) * CONST_SCALE + 0.5))
360
361/* Multiply an INT32 variable by an INT32 constant to yield an INT32 result.
362 * This macro is used only when the two inputs will actually be no more than
363 * 16 bits wide, so that a 16x16->32 bit multiply can be used instead of a
364 * full 32x32 multiply. This provides a useful speedup on many machines.
365 * Unfortunately there is no way to specify a 16x16->32 multiply portably
366 * in C, but some C compilers will do the right thing if you provide the
367 * correct combination of casts.
368 */
369
370#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
371#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT16) (const)))
372#endif
373#ifdef SHORTxLCONST_32 /* known to work with Microsoft C 6.0 */
374#define MULTIPLY16C16(var,const) (((INT16) (var)) * ((INT32) (const)))
375#endif
376
377#ifndef MULTIPLY16C16 /* default definition */
378#define MULTIPLY16C16(var,const) ((var) * (const))
379#endif
380
381/* Same except both inputs are variables. */
382
383#ifdef SHORTxSHORT_32 /* may work if 'int' is 32 bits */
384#define MULTIPLY16V16(var1,var2) (((INT16) (var1)) * ((INT16) (var2)))
385#endif
386
387#ifndef MULTIPLY16V16 /* default definition */
388#define MULTIPLY16V16(var1,var2) ((var1) * (var2))
389#endif
390
391/* Like RIGHT_SHIFT, but applies to a DCTELEM.
392 * We assume that int right shift is unsigned if INT32 right shift is.
393 */
394
395#ifdef RIGHT_SHIFT_IS_UNSIGNED
396#define ISHIFT_TEMPS DCTELEM ishift_temp;
397#if BITS_IN_JSAMPLE == 8
398#define DCTELEMBITS 16 /* DCTELEM may be 16 or 32 bits */
399#else
400#define DCTELEMBITS 32 /* DCTELEM must be 32 bits */
401#endif
402#define IRIGHT_SHIFT(x,shft) \
403 ((ishift_temp = (x)) < 0 ? \
404 (ishift_temp >> (shft)) | ((~((DCTELEM) 0)) << (DCTELEMBITS-(shft))) : \
405 (ishift_temp >> (shft)))
406#else
407#define ISHIFT_TEMPS
408#define IRIGHT_SHIFT(x,shft) ((x) >> (shft))
409#endif
signed int INT32
GLint GLenum GLsizei GLsizei GLsizei GLint GLsizei const GLvoid * data
Definition: gl.h:1950
INT32 DCTELEM
Definition: jdct.h:38
MULTIPLIER ISLOW_MULT_TYPE
Definition: jdct.h:66
jpeg_component_info JCOEFPTR coef_block
Definition: jdct.h:239
INT32 IFAST_MULT_TYPE
Definition: jdct.h:71
EXTERN(void) jpeg_fdct_islow JPP((DCTELEM *data
jpeg_component_info JCOEFPTR JSAMPARRAY JDIMENSION output_col
Definition: jdct.h:239
JSAMPARRAY JDIMENSION start_col
Definition: jdct.h:169
jpeg_component_info * compptr
Definition: jdct.h:238
FAST_FLOAT FLOAT_MULT_TYPE
Definition: jdct.h:74
jpeg_component_info JCOEFPTR JSAMPARRAY output_buf
Definition: jdct.h:239
JSAMPARRAY sample_data
Definition: jdct.h:169
unsigned int JDIMENSION
Definition: jmorecfg.h:229
#define JMETHOD(type, methodname, arglist)
Definition: jmorecfg.h:308
#define JPP(arglist)
Definition: jpeglib.h:877
JCOEF FAR * JCOEFPTR
Definition: jpeglib.h:84
JSAMPROW * JSAMPARRAY
Definition: jpeglib.h:76