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
|
/* Copyright (c) 2014, David A. Clunie DBA Pixelmed Publishing. All rights reserved. */
package com.pixelmed.codec.jpeg;
import java.io.InputStream;
import java.io.IOException;
/**
* <p>A class with various utitilies for handling byte and bit extraction.</p>
*
* @author dclunie
*/
public class Utilities {
private static final String identString = "@(#) $Header: /userland/cvs/codec/com/pixelmed/codec/jpeg/Utilities.java,v 1.1 2014/03/21 15:28:07 dclunie Exp $";
// modified from com.pixelmed.utils.HexDump.toPaddedHexString()
public static String toPaddedHexString(int i,int length) {
StringBuffer sb = new StringBuffer();
sb.append("0x");
String s=Integer.toHexString(i);
int ls=s.length();
while(ls++ < length) {
sb.append("0");
}
sb.append(s); // even if it is longer than length wanted
return sb.toString();
}
public static String toPaddedHexString(long i,int length) {
StringBuffer sb = new StringBuffer();
sb.append("0x");
String s=Long.toHexString(i);
int ls=s.length();
while(ls++ < length) {
sb.append("0");
}
sb.append(s); // even if it is longer than length wanted
return sb.toString();
}
public static final int extract8(byte[] b,int offset) {
return b[offset]&0xff;
}
public static final int extract16be(byte[] b,int offset) {
return ((b[offset]&0xff)<<8) + (b[offset+1]&0xff);
}
public static final long extract24be(byte[] b,int offset) {
return ((b[offset]&0xff)<<16) + ((b[offset+1]&0xff)<<8) + (b[offset+2]&0xff);
}
public static final long extract32be(byte[] b,int offset) {
return ((b[offset]&0xff)<<24) + ((b[offset+1]&0xff)<<16) + ((b[offset+2]&0xff)<<8) + (b[offset+3]&0xff);
}
public static final int read16be(InputStream in) throws IOException {
// big-endian
int u;
byte b[] = new byte[2];
int count = in.read(b,0,2);
if (count == 2) {
u = extract16be(b,0);
}
else {
u = -1; // OK as EOF/failure value since int is 32 bits and valid can only be 16
}
return u;
}
}
|
