2 #------------------------------------------------------------------------------
3 # $File: jpeg,v 1.16 2011/01/04 19:29:32 rrt Exp $
7 # 0 string \377\330\377\340 JPEG file
8 # 0 string \377\330\377\356 JPG file
10 # both of which turn into "JPEG image data" here.
12 0 beshort 0xffd8 JPEG image data
16 >6 string JFIF \b, JFIF standard
17 # The following added by Erik Rossen <rossen@freesurf.ch> 1999-09-06
18 # in a vain attempt to add image size reporting for JFIF. Note that these
19 # tests are not fool-proof since some perfectly valid JPEGs are currently
20 # impossible to specify in magic(4) format.
21 # First, a little JFIF version info:
24 # Next, the resolution or aspect ratio of the image:
25 #>>13 byte 0 \b, aspect ratio
26 #>>13 byte 1 \b, resolution (DPI)
27 #>>13 byte 2 \b, resolution (DPCM)
28 #>>4 beshort x \b, segment length %d
29 # Next, show thumbnail info, if it exists:
30 >>18 byte !0 \b, thumbnail %dx
33 # EXIF moved down here to avoid reporting a bogus version number,
34 # and EXIF version number printing added.
35 # - Patrik R=E5dman <patrik+file-magic@iki.fi>
36 >6 string Exif \b, EXIF standard
37 # Look for EXIF IFD offset in IFD 0, and then look for EXIF version tag in EXIF IFD.
38 # All possible combinations of entries have to be enumerated, since no looping
39 # is possible. And both endians are possible...
40 # The combinations included below are from real-world JPEGs.
46 >>>>(78.l+14) leshort 0x9000
47 >>>>>(78.l+23) byte x %c
48 >>>>>(78.l+24) byte x \b.%c
49 >>>>>(78.l+25) byte !0x30 \b%c
53 >>>>(126.l+38) leshort 0x9000
54 >>>>>(126.l+47) byte x %c
55 >>>>>(126.l+48) byte x \b.%c
56 >>>>>(126.l+49) byte !0x30 \b%c
60 >>>>(138.l+38) leshort 0x9000
61 >>>>>(138.l+47) byte x %c
62 >>>>>(138.l+48) byte x \b.%c
63 >>>>>(138.l+49) byte !0x30 \b%c
65 >>>>(138.l+50) leshort 0x9000
66 >>>>>(138.l+59) byte x %c
67 >>>>>(138.l+60) byte x \b.%c
68 >>>>>(138.l+61) byte !0x30 \b%c
70 >>>>(138.l+62) leshort 0x9000
71 >>>>>(138.l+71) byte x %c
72 >>>>>(138.l+72) byte x \b.%c
73 >>>>>(138.l+73) byte !0x30 \b%c
77 >>>>(150.l+38) leshort 0x9000
78 >>>>>(150.l+47) byte x %c
79 >>>>>(150.l+48) byte x \b.%c
80 >>>>>(150.l+49) byte !0x30 \b%c
82 >>>>(150.l+50) leshort 0x9000
83 >>>>>(150.l+59) byte x %c
84 >>>>>(150.l+60) byte x \b.%c
85 >>>>>(150.l+61) byte !0x30 \b%c
87 >>>>(150.l+62) leshort 0x9000
88 >>>>>(150.l+71) byte x %c
89 >>>>>(150.l+72) byte x \b.%c
90 >>>>>(150.l+73) byte !0x30 \b%c
96 >>>>(126.L+14) beshort 0x9000
97 >>>>>(126.L+23) byte x %c
98 >>>>>(126.L+24) byte x \b.%c
99 >>>>>(126.L+25) byte !0x30 \b%c
101 >>>>(126.L+38) beshort 0x9000
102 >>>>>(126.L+47) byte x %c
103 >>>>>(126.L+48) byte x \b.%c
104 >>>>>(126.L+49) byte !0x30 \b%c
106 >>>130 beshort 0x8769
108 >>>>(138.L+38) beshort 0x9000
109 >>>>>(138.L+47) byte x %c
110 >>>>>(138.L+48) byte x \b.%c
111 >>>>>(138.L+49) byte !0x30 \b%c
113 >>>>(138.L+62) beshort 0x9000
114 >>>>>(138.L+71) byte x %c
115 >>>>>(138.L+72) byte x \b.%c
116 >>>>>(138.L+73) byte !0x30 \b%c
118 >>>142 beshort 0x8769
120 >>>>(150.L+50) beshort 0x9000
121 >>>>>(150.L+59) byte x %c
122 >>>>>(150.L+60) byte x \b.%c
123 >>>>>(150.L+61) byte !0x30 \b%c
124 # Here things get sticky. We can do ONE MORE marker segment with
125 # indirect addressing, and that's all. It would be great if we could
126 # do pointer arithemetic like in an assembler language. Christos?
127 # And if there was some sort of looping construct to do searches, plus a few
128 # named accumulators, it would be even more effective...
129 # At least we can show a comment if no other segments got inserted before:
130 >(4.S+5) byte 0xFE \b, comment:
131 >>(4.S+6) pstring/HJ x "%s"
132 # Or, we can show the encoding type (I've included only the three most common)
133 # and image dimensions if we are lucky and the SOFn (image segment) is here:
134 >(4.S+5) byte 0xC0 \b, baseline
135 >>(4.S+6) byte x \b, precision %d
136 >>(4.S+7) beshort x \b, %dx
137 >>(4.S+9) beshort x \b%d
138 >(4.S+5) byte 0xC1 \b, extended sequential
139 >>(4.S+6) byte x \b, precision %d
140 >>(4.S+7) beshort x \b, %dx
141 >>(4.S+9) beshort x \b%d
142 >(4.S+5) byte 0xC2 \b, progressive
143 >>(4.S+6) byte x \b, precision %d
144 >>(4.S+7) beshort x \b, %dx
145 >>(4.S+9) beshort x \b%d
146 # I've commented-out quantisation table reporting. I doubt anyone cares yet.
147 #>(4.S+5) byte 0xDB \b, quantisation table
148 #>>(4.S+6) beshort x \b length=%d
149 #>14 beshort x \b, %d x
152 # HSI is Handmade Software's proprietary JPEG encoding scheme
153 0 string hsi1 JPEG image data, HSI proprietary
155 # From: David Santinoli <david@santinoli.com>
156 0 string \x00\x00\x00\x0C\x6A\x50\x20\x20\x0D\x0A\x87\x0A JPEG 2000 image data
158 # Type: JPEG 2000 codesream
159 # From: Mathieu Malaterre <mathieu.malaterre@gmail.com>
160 0 belong 0xff4fff51 JPEG 2000 codestream