1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
|
/*******************************************************************************
* Copyright (c) 2000, 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.swt.internal.image;
/**
* JPEGHuffmanTable class actually represents two types of object:
* 1) A DHT (Define Huffman Tables) segment, which may represent
* as many as 4 Huffman tables. In this case, the tables are
* stored in the allTables array.
* 2) A single Huffman table. In this case, the allTables array
* will be null.
* The 'reference' field is stored in both types of object, but
* 'initialize' is only called if the object represents a DHT.
*/
final class JPEGHuffmanTable extends JPEGVariableSizeSegment {
JPEGHuffmanTable[] allTables;
int tableClass;
int tableIdentifier;
int[] dhMaxCodes;
int[] dhMinCodes;
int[] dhValPtrs;
int[] dhValues;
int[] ehCodes;
byte[] ehCodeLengths;
static byte[] DCLuminanceTable = {
(byte)255, (byte)196, 0, 31, 0, 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
};
static byte[] DCChrominanceTable = {
(byte)255, (byte)196, 0, 31, 1, 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
};
static byte[] ACLuminanceTable = {
(byte)255, (byte)196, 0, (byte)181, 16, 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 125,
1, 2, 3, 0, 4, 17, 5, 18, 33, 49, 65, 6, 19, 81, 97, 7, 34, 113, 20,
50, (byte)129, (byte)145, (byte)161, 8, 35, 66, (byte)177, (byte)193, 21, 82, (byte)209, (byte)240, 36, 51, 98,
114, (byte)130, 9, 10, 22, 23, 24, 25, 26, 37, 38, 39, 40, 41, 42, 52, 53,
54, 55, 56, 57, 58, 67, 68, 69, 70, 71, 72, 73, 74, 83, 84, 85, 86, 87,
88, 89, 90, 99, 100, 101, 102, 103, 104, 105, 106, 115, 116, 117, 118,
119, 120, 121, 122, (byte)131, (byte)132, (byte)133, (byte)134, (byte)135, (byte)136, (byte)137, (byte)138, (byte)146, (byte)147, (byte)148,
(byte)149, (byte)150, (byte)151, (byte)152, (byte)153, (byte)154, (byte)162, (byte)163, (byte)164, (byte)165, (byte)166, (byte)167, (byte)168, (byte)169, (byte)170,
(byte)178, (byte)179, (byte)180, (byte)181, (byte)182, (byte)183, (byte)184, (byte)185, (byte)186, (byte)194, (byte)195, (byte)196, (byte)197, (byte)198, (byte)199,
(byte)200, (byte)201, (byte)202, (byte)210, (byte)211, (byte)212, (byte)213, (byte)214, (byte)215, (byte)216, (byte)217, (byte)218, (byte)225, (byte)226, (byte)227,
(byte)228, (byte)229, (byte)230, (byte)231, (byte)232, (byte)233, (byte)234, (byte)241, (byte)242, (byte)243, (byte)244, (byte)245, (byte)246, (byte)247, (byte)248,
(byte)249, (byte)250
};
static byte[] ACChrominanceTable = {
(byte)255, (byte)196, 0, (byte)181, 17, 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0,
1, 2, 119, 0, 1, 2, 3, 17, 4, 5, 33, 49, 6, 18, 65, 81, 7, 97, 113, 19, 34,
50, (byte)129, 8, 20, 66, (byte)145, (byte)161, (byte)177, (byte)193, 9, 35,
51, 82, (byte)240, 21, 98, 114, (byte)209, 10, 22, 36, 52, (byte)225, 37,
(byte)241, 23, 24, 25, 26, 38, 39, 40, 41, 42, 53, 54, 55, 56, 57, 58, 67,
68, 69, 70, 71, 72, 73, 74, 83, 84, 85, 86, 87, 88, 89, 90, 99, 100, 101, 102,
103, 104, 105, 106, 115, 116, 117, 118, 119, 120, 121, 122, (byte)130,
(byte)131, (byte)132, (byte)133, (byte)134, (byte)135, (byte)136, (byte)137,
(byte)138, (byte)146, (byte)147, (byte)148, (byte)149, (byte)150, (byte)151,
(byte)152, (byte)153, (byte)154, (byte)162, (byte)163, (byte)164, (byte)165,
(byte)166, (byte)167, (byte)168, (byte)169, (byte)170, (byte)178, (byte)179,
(byte)180, (byte)181, (byte)182, (byte)183, (byte)184, (byte)185, (byte)186,
(byte)194, (byte)195, (byte)196, (byte)197, (byte)198, (byte)199, (byte)200,
(byte)201, (byte)202, (byte)210, (byte)211, (byte)212, (byte)213, (byte)214,
(byte)215, (byte)216, (byte)217, (byte)218, (byte)226, (byte)227, (byte)228,
(byte)229, (byte)230, (byte)231, (byte)232, (byte)233, (byte)234, (byte)242,
(byte)243, (byte)244, (byte)245, (byte)246, (byte)247, (byte)248, (byte)249,
(byte)250
};
public JPEGHuffmanTable(byte[] reference) {
super(reference);
}
public JPEGHuffmanTable(LEDataInputStream byteStream) {
super(byteStream);
initialize();
}
public JPEGHuffmanTable[] getAllTables() {
return allTables;
}
public static JPEGHuffmanTable getDefaultACChrominanceTable() {
JPEGHuffmanTable result = new JPEGHuffmanTable(ACChrominanceTable);
result.initialize();
return result;
}
public static JPEGHuffmanTable getDefaultACLuminanceTable() {
JPEGHuffmanTable result = new JPEGHuffmanTable(ACLuminanceTable);
result.initialize();
return result;
}
public static JPEGHuffmanTable getDefaultDCChrominanceTable() {
JPEGHuffmanTable result = new JPEGHuffmanTable(DCChrominanceTable);
result.initialize();
return result;
}
public static JPEGHuffmanTable getDefaultDCLuminanceTable() {
JPEGHuffmanTable result = new JPEGHuffmanTable(DCLuminanceTable);
result.initialize();
return result;
}
public int[] getDhMaxCodes() {
return dhMaxCodes;
}
public int[] getDhMinCodes() {
return dhMinCodes;
}
public int[] getDhValPtrs() {
return dhValPtrs;
}
public int[] getDhValues() {
return dhValues;
}
public int getTableClass() {
return tableClass;
}
public int getTableIdentifier() {
return tableIdentifier;
}
void initialize() {
int totalLength = getSegmentLength() - 2;
int ofs = 4;
int[] bits = new int[16];
JPEGHuffmanTable[] huffTables = new JPEGHuffmanTable[8]; // maximum is 4 AC + 4 DC
int huffTableCount = 0;
while (totalLength > 0) {
int tc = (reference[ofs] & 0xFF) >> 4; // table class: AC (1) or DC (0)
int tid = reference[ofs] & 0xF; // table id: 0-1 baseline, 0-3 prog/ext
ofs++;
/* Read the 16 count bytes and add them together to get the table size. */
int count = 0;
for (int i = 0; i < bits.length; i++) {
int bCount = reference[ofs + i] & 0xFF;
bits[i] = bCount;
count += bCount;
}
ofs += 16;
totalLength -= 17;
/* Read the table. */
int[] huffVals = new int[count];
for (int i = 0; i < count; i++) {
huffVals[i] = reference[ofs + i] & 0xFF;
}
ofs += count;
totalLength -= count;
/* Calculate the lengths. */
int[] huffCodeLengths = new int[50]; // start with 50 and increment as needed
int huffCodeLengthsIndex = 0;
for (int i = 0; i < 16; i++) {
for (int j = 0; j < bits[i]; j++) {
if (huffCodeLengthsIndex >= huffCodeLengths.length) {
int[] newHuffCodeLengths = new int[huffCodeLengths.length + 50];
System.arraycopy(huffCodeLengths, 0, newHuffCodeLengths, 0, huffCodeLengths.length);
huffCodeLengths = newHuffCodeLengths;
}
huffCodeLengths[huffCodeLengthsIndex] = i + 1;
huffCodeLengthsIndex++;
}
}
/* Truncate huffCodeLengths to the correct size. */
if (huffCodeLengthsIndex < huffCodeLengths.length) {
int[] newHuffCodeLengths = new int[huffCodeLengthsIndex];
System.arraycopy(huffCodeLengths, 0, newHuffCodeLengths, 0, huffCodeLengthsIndex);
huffCodeLengths = newHuffCodeLengths;
}
/* Calculate the Huffman codes. */
int[] huffCodes = new int[50]; // start with 50 and increment as needed
int huffCodesIndex = 0;
int k = 1;
int code = 0;
int si = huffCodeLengths[0];
int p = 0;
while (p < huffCodeLengthsIndex) {
while ((p < huffCodeLengthsIndex) && (huffCodeLengths[p] == si)) {
if (huffCodesIndex >= huffCodes.length) {
int[] newHuffCodes = new int[huffCodes.length + 50];
System.arraycopy(huffCodes, 0, newHuffCodes, 0, huffCodes.length);
huffCodes = newHuffCodes;
}
huffCodes[huffCodesIndex] = code;
huffCodesIndex++;
code++;
p++;
}
code *= 2;
si++;
}
/* Truncate huffCodes to the correct size. */
if (huffCodesIndex < huffCodes.length) {
int[] newHuffCodes = new int[huffCodesIndex];
System.arraycopy(huffCodes, 0, newHuffCodes, 0, huffCodesIndex);
huffCodes = newHuffCodes;
}
/* Calculate the maximum and minimum codes */
k = 0;
int[] maxCodes = new int[16];
int[] minCodes = new int[16];
int[] valPtrs = new int[16];
for (int i = 0; i < 16; i++) {
int bSize = bits[i];
if (bSize == 0) {
maxCodes[i] = -1;
} else {
valPtrs[i] = k;
minCodes[i] = huffCodes[k];
k += bSize;
maxCodes[i] = huffCodes[k - 1];
}
}
/* Calculate the eHuffman codes and lengths. */
int[] eHuffCodes = new int[256];
byte[] eHuffSize = new byte[256];
for (int i = 0; i < huffCodesIndex; i++) {
eHuffCodes[huffVals[i]] = huffCodes[i];
eHuffSize[huffVals[i]] = (byte)huffCodeLengths[i];
}
/* Create the new JPEGHuffmanTable and add it to the allTables array. */
JPEGHuffmanTable dhtTable = new JPEGHuffmanTable(reference);
dhtTable.tableClass = tc;
dhtTable.tableIdentifier = tid;
dhtTable.dhValues = huffVals;
dhtTable.dhMinCodes = minCodes;
dhtTable.dhMaxCodes = maxCodes;
dhtTable.dhValPtrs = valPtrs;
dhtTable.ehCodes = eHuffCodes;
dhtTable.ehCodeLengths = eHuffSize;
huffTables[huffTableCount] = dhtTable;
huffTableCount++;
}
allTables = new JPEGHuffmanTable[huffTableCount];
System.arraycopy(huffTables, 0, allTables, 0, huffTableCount);
}
public int signature() {
return JPEGFileFormat.DHT;
}
}
|
