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jutils.cpp
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1 /* +---------------------------------------------------------------------------+
2  | Mobile Robot Programming Toolkit (MRPT) |
3  | http://www.mrpt.org/ |
4  | |
5  | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file |
6  | See: http://www.mrpt.org/Authors - All rights reserved. |
7  | Released under BSD License. See details in http://www.mrpt.org/License |
8  +---------------------------------------------------------------------------+ */
9 
10 #define JPEG_INTERNALS
11 #include "jinclude.h"
12 #include "mrpt_jpeglib.h"
13 
14 
15 /*
16  * jpeg_zigzag_order[i] is the zigzag-order position of the i'th element
17  * of a DCT block read in natural order (left to right, top to bottom).
18  */
19 
20 #if 0 /* This table is not actually needed in v6a */
21 
22 const int jpeg_zigzag_order[DCTSIZE2] = {
23  0, 1, 5, 6, 14, 15, 27, 28,
24  2, 4, 7, 13, 16, 26, 29, 42,
25  3, 8, 12, 17, 25, 30, 41, 43,
26  9, 11, 18, 24, 31, 40, 44, 53,
27  10, 19, 23, 32, 39, 45, 52, 54,
28  20, 22, 33, 38, 46, 51, 55, 60,
29  21, 34, 37, 47, 50, 56, 59, 61,
30  35, 36, 48, 49, 57, 58, 62, 63
31 };
32 
33 #endif
34 
35 /*
36  * jpeg_natural_order[i] is the natural-order position of the i'th element
37  * of zigzag order.
38  *
39  * When reading corrupted data, the Huffman decoders could attempt
40  * to reference an entry beyond the end of this array (if the decoded
41  * zero run length reaches past the end of the block). To prevent
42  * wild stores without adding an inner-loop test, we put some extra
43  * "63"s after the real entries. This will cause the extra coefficient
44  * to be stored in location 63 of the block, not somewhere random.
45  * The worst case would be a run-length of 15, which means we need 16
46  * fake entries.
47  */
48 
49 const int jpeg_natural_order[DCTSIZE2+16] = {
50  0, 1, 8, 16, 9, 2, 3, 10,
51  17, 24, 32, 25, 18, 11, 4, 5,
52  12, 19, 26, 33, 40, 48, 41, 34,
53  27, 20, 13, 6, 7, 14, 21, 28,
54  35, 42, 49, 56, 57, 50, 43, 36,
55  29, 22, 15, 23, 30, 37, 44, 51,
56  58, 59, 52, 45, 38, 31, 39, 46,
57  53, 60, 61, 54, 47, 55, 62, 63,
58  63, 63, 63, 63, 63, 63, 63, 63, /* extra entries for safety in decoder */
59  63, 63, 63, 63, 63, 63, 63, 63
60 };
61 
62 
63 /*
64  * Arithmetic utilities
65  */
66 
67 GLOBAL(long)
68 jdiv_round_up (long a, long b)
69 /* Compute a/b rounded up to next integer, ie, ceil(a/b) */
70 /* Assumes a >= 0, b > 0 */
71 {
72  return (a + b - 1L) / b;
73 }
74 
75 
76 GLOBAL(long)
77 jround_up (long a, long b)
78 /* Compute a rounded up to next multiple of b, ie, ceil(a/b)*b */
79 /* Assumes a >= 0, b > 0 */
80 {
81  a += b - 1L;
82  return a - (a % b);
83 }
84 
85 
86 /* On normal machines we can apply MEMCOPY() and MEMZERO() to sample arrays
87  * and coefficient-block arrays. This won't work on 80x86 because the arrays
88  * are FAR and we're assuming a small-pointer memory model. However, some
89  * DOS compilers provide far-pointer versions of memcpy() and memset() even
90  * in the small-model libraries. These will be used if USE_FMEM is defined.
91  * Otherwise, the routines below do it the hard way. (The performance cost
92  * is not all that great, because these routines aren't very heavily used.)
93  */
94 
95 #ifndef NEED_FAR_POINTERS /* normal case, same as regular macros */
96 #define FMEMCOPY(dest,src,size) MEMCOPY(dest,src,size)
97 #define FMEMZERO(target,size) MEMZERO(target,size)
98 #else /* 80x86 case, define if we can */
99 #ifdef USE_FMEM
100 #define FMEMCOPY(dest,src,size) _fmemcpy((void FAR *)(dest), (const void FAR *)(src), (size_t)(size))
101 #define FMEMZERO(target,size) _fmemset((void FAR *)(target), 0, (size_t)(size))
102 #endif
103 #endif
104 
105 
106 GLOBAL(void)
110 /* Copy some rows of samples from one place to another.
111  * num_rows rows are copied from input_array[source_row++]
112  * to output_array[dest_row++]; these areas may overlap for duplication.
113  * The source and destination arrays must be at least as wide as num_cols.
114  */
115 {
116  JSAMPROW inptr, outptr;
117 #ifdef FMEMCOPY
118  size_t count = (size_t) (num_cols * SIZEOF(JSAMPLE));
119 #else
121 #endif
122  int row;
123 
124  input_array += source_row;
125  output_array += dest_row;
126 
127  for (row = num_rows; row > 0; row--) {
128  inptr = *input_array++;
129  outptr = *output_array++;
130 #ifdef FMEMCOPY
131  FMEMCOPY(outptr, inptr, count);
132 #else
133  for (count = num_cols; count > 0; count--)
134  *outptr++ = *inptr++; /* needn't bother with GETJSAMPLE() here */
135 #endif
136  }
137 }
138 
139 
140 GLOBAL(void)
143 /* Copy a row of coefficient blocks from one place to another. */
144 {
145 #ifdef FMEMCOPY
146  FMEMCOPY(output_row, input_row, num_blocks * (DCTSIZE2 * SIZEOF(JCOEF)));
147 #else
148  JCOEFPTR inptr, outptr;
149  long count;
150 
151  inptr = (JCOEFPTR) input_row;
152  outptr = (JCOEFPTR) output_row;
153  for (count = (long) num_blocks * DCTSIZE2; count > 0; count--) {
154  *outptr++ = *inptr++;
155  }
156 #endif
157 }
158 
159 
160 GLOBAL(void)
161 jzero_far (void FAR * target, size_t bytestozero)
162 /* Zero out a chunk of FAR memory. */
163 /* This might be sample-array data, block-array data, or alloc_large data. */
164 {
165 #ifdef FMEMZERO
166  FMEMZERO(target, bytestozero);
167 #else
168  char FAR * ptr = (char FAR *) target;
169  size_t count;
170 
171  for (count = bytestozero; count > 0; count--) {
172  *ptr++ = 0;
173  }
174 #endif
175 }
GLboolean GLboolean GLboolean GLboolean a
Definition: glew.h:5406
jzero_far(void FAR *target, size_t bytestozero)
Definition: jutils.cpp:161
jdiv_round_up(long a, long b)
Definition: jutils.cpp:68
char JSAMPLE
Definition: jmorecfg.h:61
GLenum GLenum GLvoid * row
Definition: glew.h:2903
jcopy_block_row(JBLOCKROW input_row, JBLOCKROW output_row, JDIMENSION num_blocks)
Definition: jutils.cpp:141
jround_up(long a, long b)
Definition: jutils.cpp:77
#define SIZEOF(object)
Definition: jinclude.h:73
JSAMPLE FAR * JSAMPROW
Definition: mrpt_jpeglib.h:63
short JCOEF
Definition: jmorecfg.h:96
jcopy_sample_rows(JSAMPARRAY input_array, int source_row, JSAMPARRAY output_array, int dest_row, int num_rows, JDIMENSION num_cols)
Definition: jutils.cpp:107
const int jpeg_natural_order[DCTSIZE2+16]
Definition: jutils.cpp:49
#define FMEMZERO(target, size)
Definition: jutils.cpp:97
int JSAMPARRAY int dest_row
Definition: jpegint.h:370
JBLOCKROW JDIMENSION num_blocks
Definition: jpegint.h:373
JSAMPROW * JSAMPARRAY
Definition: mrpt_jpeglib.h:64
JCOEF FAR * JCOEFPTR
Definition: mrpt_jpeglib.h:72
int source_row
Definition: jpegint.h:370
#define DCTSIZE2
Definition: mrpt_jpeglib.h:39
JBLOCKROW output_row
Definition: jpegint.h:373
size_t bytestozero
Definition: jpegint.h:375
int JSAMPARRAY int int num_rows
Definition: jpegint.h:370
int JSAMPARRAY int int JDIMENSION num_cols
Definition: jpegint.h:370
GLenum target
Definition: glew.h:5023
#define GLOBAL(type)
Definition: jmorecfg.h:185
JBLOCK FAR * JBLOCKROW
Definition: mrpt_jpeglib.h:68
GLuint GLuint GLsizei count
Definition: glew.h:1167
GLdouble GLdouble GLdouble b
Definition: glew.h:5092
unsigned int JDIMENSION
Definition: jmorecfg.h:168
#define FAR
Definition: zconf.h:261
#define FMEMCOPY(dest, src, size)
Definition: jutils.cpp:96
int JSAMPARRAY output_array
Definition: jpegint.h:370



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