diff options
Diffstat (limited to 'contrib/file/Magdir/jpeg')
| -rw-r--r-- | contrib/file/Magdir/jpeg | 115 |
1 files changed, 103 insertions, 12 deletions
diff --git a/contrib/file/Magdir/jpeg b/contrib/file/Magdir/jpeg index bedc6c9..af646d6 100644 --- a/contrib/file/Magdir/jpeg +++ b/contrib/file/Magdir/jpeg @@ -10,22 +10,113 @@ # 0 beshort 0xffd8 JPEG image data >6 string JFIF \b, JFIF standard ->6 string Exif \b, EXIF 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 +>>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 +#>>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 +>>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? @@ -33,7 +124,7 @@ # 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, "%s" +>>(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" @@ -54,8 +145,8 @@ # 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 +#>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 |
