freebsd-dev/contrib/file/Magdir/compress
2002-09-16 05:54:26 +00:00

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#------------------------------------------------------------------------------
# compress: file(1) magic for pure-compression formats (no archives)
#
# compress, gzip, pack, compact, huf, squeeze, crunch, freeze, yabba, etc.
#
# Formats for various forms of compressed data
# Formats for "compress" proper have been moved into "compress.c",
# because it tries to uncompress it to figure out what's inside.
# standard unix compress
0 string \037\235 compress'd data
>2 byte&0x80 >0 block compressed
>2 byte&0x1f x %d bits
# gzip (GNU zip, not to be confused with Info-ZIP or PKWARE zip archiver)
# Edited by Chris Chittleborough <cchittleborough@yahoo.com.au>, March 2002
# * Original filename is only at offset 10 if "extra field" absent
# * Produce shorter output - notably, only report compression methods
# other than 8 ("deflate", the only method defined in RFC 1952).
0 string \037\213 gzip compressed data
>2 byte <8 \b, reserved method
>2 byte >8 \b, unknown method
>3 byte &0x01 \b, ASCII
>3 byte &0x02 \b, continuation
>3 byte &0x04 \b, extra field
>3 byte&0xC =0x08
>>10 string x \b, was "%s"
>9 byte =0x00 \b, from MS-DOS
>9 byte =0x01 \b, from Amiga
>9 byte =0x02 \b, from VMS
>9 byte =0x03 \b, from Unix
>9 byte =0x05 \b, from Atari
>9 byte =0x06 \b, from OS/2
>9 byte =0x07 \b, from MacOS
>9 byte =0x0A \b, from Tops/20
>9 byte =0x0B \b, from Win/32
>3 byte &0x10 \b, comment
>3 byte &0x20 \b, encrypted
### >4 ledate x last modified: %s,
>8 byte 2 \b, max compression
>8 byte 4 \b, max speed
# packed data, Huffman (minimum redundancy) codes on a byte-by-byte basis
0 string \037\036 packed data
>2 belong >1 \b, %d characters originally
>2 belong =1 \b, %d character originally
#
# This magic number is byte-order-independent. XXX - Does that mean this
# is big-endian, little-endian, either, or that you can't tell?
# this short is valid for SunOS
0 short 017437 old packed data
# XXX - why *two* entries for "compacted data", one of which is
# byte-order independent, and one of which is byte-order dependent?
#
0 short 0x1fff compacted data
# This string is valid for SunOS (BE) and a matching "short" is listed
# in the Ultrix (LE) magic file.
0 string \377\037 compacted data
0 short 0145405 huf output
# bzip2
0 string BZh bzip2 compressed data
>3 byte >47 \b, block size = %c00k
# squeeze and crunch
# Michael Haardt <michael@cantor.informatik.rwth-aachen.de>
0 beshort 0x76FF squeezed data,
>4 string x original name %s
0 beshort 0x76FE crunched data,
>2 string x original name %s
0 beshort 0x76FD LZH compressed data,
>2 string x original name %s
# Freeze
0 string \037\237 frozen file 2.1
0 string \037\236 frozen file 1.0 (or gzip 0.5)
# SCO compress -H (LZH)
0 string \037\240 SCO compress -H (LZH) data
# European GSM 06.10 is a provisional standard for full-rate speech
# transcoding, prI-ETS 300 036, which uses RPE/LTP (residual pulse
# excitation/long term prediction) coding at 13 kbit/s.
#
# There's only a magic nibble (4 bits); that nibble repeats every 33
# bytes. This isn't suited for use, but maybe we can use it someday.
#
# This will cause very short GSM files to be declared as data and
# mismatches to be declared as data too!
#0 byte&0xF0 0xd0 data
#>33 byte&0xF0 0xd0
#>66 byte&0xF0 0xd0
#>99 byte&0xF0 0xd0
#>132 byte&0xF0 0xd0 GSM 06.10 compressed audio
# bzip a block-sorting file compressor
# by Julian Seward <sewardj@cs.man.ac.uk> and others
#
0 string BZ bzip compressed data
>2 byte x \b, version: %c
>3 string =1 \b, compression block size 100k
>3 string =2 \b, compression block size 200k
>3 string =3 \b, compression block size 300k
>3 string =4 \b, compression block size 400k
>3 string =5 \b, compression block size 500k
>3 string =6 \b, compression block size 600k
>3 string =7 \b, compression block size 700k
>3 string =8 \b, compression block size 800k
>3 string =9 \b, compression block size 900k
# lzop from <markus.oberhumer@jk.uni-linz.ac.at>
0 string \x89\x4c\x5a\x4f\x00\x0d\x0a\x1a\x0a lzop compressed data
>9 beshort <0x0940
>>9 byte&0xf0 =0x00 - version 0.
>>9 beshort&0x0fff x \b%03x,
>>13 byte 1 LZO1X-1,
>>13 byte 2 LZO1X-1(15),
>>13 byte 3 LZO1X-999,
## >>22 bedate >0 last modified: %s,
>>14 byte =0x00 os: MS-DOS
>>14 byte =0x01 os: Amiga
>>14 byte =0x02 os: VMS
>>14 byte =0x03 os: Unix
>>14 byte =0x05 os: Atari
>>14 byte =0x06 os: OS/2
>>14 byte =0x07 os: MacOS
>>14 byte =0x0A os: Tops/20
>>14 byte =0x0B os: WinNT
>>14 byte =0x0E os: Win32
>9 beshort >0x0939
>>9 byte&0xf0 =0x00 - version 0.
>>9 byte&0xf0 =0x10 - version 1.
>>9 byte&0xf0 =0x20 - version 2.
>>9 beshort&0x0fff x \b%03x,
>>15 byte 1 LZO1X-1,
>>15 byte 2 LZO1X-1(15),
>>15 byte 3 LZO1X-999,
## >>25 bedate >0 last modified: %s,
>>17 byte =0x00 os: MS-DOS
>>17 byte =0x01 os: Amiga
>>17 byte =0x02 os: VMS
>>17 byte =0x03 os: Unix
>>17 byte =0x05 os: Atari
>>17 byte =0x06 os: OS/2
>>17 byte =0x07 os: MacOS
>>17 byte =0x0A os: Tops/20
>>17 byte =0x0B os: WinNT
>>17 byte =0x0E os: Win32
# 4.3BSD-Quasijarus Strong Compression
# http://minnie.tuhs.org/Quasijarus/compress.html
0 string \037\241 Quasijarus strong compressed data