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
|
#------------------------------------------------------------------------------
# JPEG images
# SunOS 5.5.1 had
#
# 0 string \377\330\377\340 JPEG file
# 0 string \377\330\377\356 JPG file
#
# both of which turn into "JPEG image data" here.
#
0 beshort 0xffd8 JPEG image data
>6 string JFIF \b, JFIF standard
# The following added by Erik Rossen <rossen@freesurf.ch> 1999-09-06
# in a vain attempt to add image size reporting for JFIF. Note that these
# tests are not fool-proof since some perfectly valid JPEGs are currently
# impossible to specify in magic(4) format.
# First, a little JFIF version info:
>>11 byte x \b %d.
>>12 byte x \b%02d
# Next, the resolution or aspect ratio of the image:
#>>13 byte 0 \b, aspect ratio
#>>13 byte 1 \b, resolution (DPI)
#>>13 byte 2 \b, resolution (DPCM)
#>>4 beshort x \b, segment length %d
# Next, show thumbnail info, if it exists:
>>18 byte !0 \b, thumbnail %dx
>>>19 byte x \b%d
# EXIF moved down here to avoid reporting a bogus version number,
# and EXIF version number printing added.
# - Patrik R=E5dman <patrik+file-magic@iki.fi>
>6 string Exif \b, EXIF standard
# Look for EXIF IFD offset in IFD 0, and then look for EXIF version tag in EXIF IFD.
# All possible combinations of entries have to be enumerated, since no looping
# is possible. And both endians are possible...
# The combinations included below are from real-world JPEGs.
# Little-endian
>>12 string II
# IFD 0 Entry #5:
>>>70 leshort 0x8769
# EXIF IFD Entry #1:
>>>>(78.l+14) leshort 0x9000
>>>>>(78.l+23) byte x %c
>>>>>(78.l+24) byte x \b.%c
>>>>>(78.l+25) byte !0x30 \b%c
# IFD 0 Entry #9:
>>>118 leshort 0x8769
# EXIF IFD Entry #3:
>>>>(126.l+38) leshort 0x9000
>>>>>(126.l+47) byte x %c
>>>>>(126.l+48) byte x \b.%c
>>>>>(126.l+49) byte !0x30 \b%c
# IFD 0 Entry #10
>>>130 leshort 0x8769
# EXIF IFD Entry #3:
>>>>(138.l+38) leshort 0x9000
>>>>>(138.l+47) byte x %c
>>>>>(138.l+48) byte x \b.%c
>>>>>(138.l+49) byte !0x30 \b%c
# EXIF IFD Entry #4:
>>>>(138.l+50) leshort 0x9000
>>>>>(138.l+59) byte x %c
>>>>>(138.l+60) byte x \b.%c
>>>>>(138.l+61) byte !0x30 \b%c
# EXIF IFD Entry #5:
>>>>(138.l+62) leshort 0x9000
>>>>>(138.l+71) byte x %c
>>>>>(138.l+72) byte x \b.%c
>>>>>(138.l+73) byte !0x30 \b%c
# IFD 0 Entry #11
>>>142 leshort 0x8769
# EXIF IFD Entry #3:
>>>>(150.l+38) leshort 0x9000
>>>>>(150.l+47) byte x %c
>>>>>(150.l+48) byte x \b.%c
>>>>>(150.l+49) byte !0x30 \b%c
# EXIF IFD Entry #4:
>>>>(150.l+50) leshort 0x9000
>>>>>(150.l+59) byte x %c
>>>>>(150.l+60) byte x \b.%c
>>>>>(150.l+61) byte !0x30 \b%c
# EXIF IFD Entry #5:
>>>>(150.l+62) leshort 0x9000
>>>>>(150.l+71) byte x %c
>>>>>(150.l+72) byte x \b.%c
>>>>>(150.l+73) byte !0x30 \b%c
# Big-endian
>>12 string MM
# IFD 0 Entry #9:
>>>118 beshort 0x8769
# EXIF IFD Entry #1:
>>>>(126.L+14) beshort 0x9000
>>>>>(126.L+23) byte x %c
>>>>>(126.L+24) byte x \b.%c
>>>>>(126.L+25) byte !0x30 \b%c
# EXIF IFD Entry #3:
>>>>(126.L+38) beshort 0x9000
>>>>>(126.L+47) byte x %c
>>>>>(126.L+48) byte x \b.%c
>>>>>(126.L+49) byte !0x30 \b%c
# IFD 0 Entry #10
>>>130 beshort 0x8769
# EXIF IFD Entry #3:
>>>>(138.L+38) beshort 0x9000
>>>>>(138.L+47) byte x %c
>>>>>(138.L+48) byte x \b.%c
>>>>>(138.L+49) byte !0x30 \b%c
# EXIF IFD Entry #5:
>>>>(138.L+62) beshort 0x9000
>>>>>(138.L+71) byte x %c
>>>>>(138.L+72) byte x \b.%c
>>>>>(138.L+73) byte !0x30 \b%c
# IFD 0 Entry #11
>>>142 beshort 0x8769
# EXIF IFD Entry #4:
>>>>(150.L+50) beshort 0x9000
>>>>>(150.L+59) byte x %c
>>>>>(150.L+60) byte x \b.%c
>>>>>(150.L+61) byte !0x30 \b%c
# Here things get sticky. We can do ONE MORE marker segment with
# indirect addressing, and that's all. It would be great if we could
# do pointer arithemetic like in an assembler language. Christos?
# And if there was some sort of looping construct to do searches, plus a few
# named accumulators, it would be even more effective...
# At least we can show a comment if no other segments got inserted before:
>(4.S+5) byte 0xFE
>>(4.S+8) string >\0 \b, comment: "%s"
#>(4.S+5) byte 0xFE \b, comment
#>>(4.S+6) beshort x \b length=%d
#>>(4.S+8) string >\0 \b, "%s"
# Or, we can show the encoding type (I've included only the three most common)
# and image dimensions if we are lucky and the SOFn (image segment) is here:
>(4.S+5) byte 0xC0 \b, baseline
>>(4.S+6) byte x \b, precision %d
>>(4.S+7) beshort x \b, %dx
>>(4.S+9) beshort x \b%d
>(4.S+5) byte 0xC1 \b, extended sequential
>>(4.S+6) byte x \b, precision %d
>>(4.S+7) beshort x \b, %dx
>>(4.S+9) beshort x \b%d
>(4.S+5) byte 0xC2 \b, progressive
>>(4.S+6) byte x \b, precision %d
>>(4.S+7) beshort x \b, %dx
>>(4.S+9) beshort x \b%d
# I've commented-out quantisation table reporting. I doubt anyone cares yet.
#>(4.S+5) byte 0xDB \b, quantisation table
#>>(4.S+6) beshort x \b length=%d
#>14 beshort x \b, %d x
#>16 beshort x \b %d
# HSI is Handmade Software's proprietary JPEG encoding scheme
0 string hsi1 JPEG image data, HSI proprietary
# From: David Santinoli <david@santinoli.com>
0 string \x00\x00\x00\x0C\x6A\x50\x20\x20\x0D\x0A\x87\x0A JPEG 2000 image data
|
