animation

UNIX下FILE命令的实现源码

#------------------------------------------------------------------------------
# animation:  file(1) magic for animation/movie formats
#
# animation formats
# MPEG, FLI, DL originally from [e-mail] (VaX#n8)
# FLC, SGI, Apple originally from Daniel Quinlan ([e-mail])

# MPEG animation format
0	belong		0x000001b3		MPEG video stream data
#>4	beshort&0xfff0	x			(%d x
#>5	beshort&0x0fff  x			%d)
0	belong		0x000001ba		MPEG system stream data

# MPEG Audio (*.mpx)
# from [e-mail]

# XXX
# This conflicts with the FF FE signature for UTF-16-encoded Unicode
# text, which will be identified as an MP3 file.  I don't have any MP3s
# so I don't know how to (or even if it's possible to) change this to
# tell the two apart.    [e-mail]

0       beshort         &0xfff0         MP
# MPEG 1.0
>1      byte&0x08       =0x08           \b
# Layer 3
>>1     byte            &0x02           \b3
>>>2    byte&0xf0       =0x10           \b,  32 kBits
>>>2    byte&0xf0       =0x20           \b,  40 kBits
>>>2    byte&0xf0       =0x30           \b,  48 kBits
>>>2    byte&0xf0       =0x40           \b,  56 kBits
>>>2    byte&0xf0       =0x50           \b,  64 kBits
>>>2    byte&0xf0       =0x60           \b,  80 kBits
>>>2    byte&0xf0       =0x70           \b,  96 kBits
>>>2    byte&0xf0       =0x80           \b, 112 kBits
>>>2    byte&0xf0       =0x90           \b, 128 kBits
>>>2    byte&0xf0       =0xA0           \b, 160 kBits
>>>2    byte&0xf0       =0xB0           \b, 192 kBits
>>>2    byte&0xf0       =0xC0           \b, 224 kBits
>>>2    byte&0xf0       =0xD0           \b, 256 kBits
>>>2    byte&0xf0       =0xE0           \b, 320 kBits
# Layer 2
>>1     byte            &0x04           \b2
>>>2    byte&0xf0       =0x10           \b,  32 kBits
>>>2    byte&0xf0       =0x20           \b,  48 kBits
>>>2    byte&0xf0       =0x30           \b,  56 kBits
>>>2    byte&0xf0       =0x40           \b,  64 kBits
>>>2    byte&0xf0       =0x50           \b,  80 kBits
>>>2    byte&0xf0       =0x60           \b,  96 kBits
>>>2    byte&0xf0       =0x70           \b, 112 kBits
>>>2    byte&0xf0       =0x80           \b, 128 kBits
>>>2    byte&0xf0       =0x90           \b, 160 kBits
>>>2    byte&0xf0       =0xA0           \b, 192 kBits
>>>2    byte&0xf0       =0xB0           \b, 224 kBits
>>>2    byte&0xf0       =0xC0           \b, 256 kBits
>>>2    byte&0xf0       =0xD0           \b, 320 kBits
>>>2    byte&0xf0       =0xE0           \b, 384 kBits
# freq
>>2     byte&0x0C       =0x00           \b, 44.1 kHz
>>2     byte&0x0C       =0x04           \b, 48 kHz
>>2     byte&0x0C       =0x08           \b, 32 kHz
# MPEG 2.0
>1      byte&0x08       =0x00           \b
# Layer 3
>>1     byte            &0x02           \b3
# Layer 2
>>1     byte            &0x04           \b2
>>2     byte&0xf0       =0x10           \b,   8 kBits
>>2     byte&0xf0       =0x20           \b,  16 kBits
>>2     byte&0xf0       =0x30           \b,  24 kBits
>>2     byte&0xf0       =0x40           \b,  32 kBits
>>2     byte&0xf0       =0x50           \b,  40 kBits
>>2     byte&0xf0       =0x60           \b,  48 kBits
>>2     byte&0xf0       =0x70           \b,  56 kBits
>>2     byte&0xf0       =0x80           \b,  64 kBits
>>2     byte&0xf0       =0x90           \b,  80 kBits
>>2     byte&0xf0       =0xA0           \b,  96 kBits
>>2     byte&0xf0       =0xB0           \b, 112 kBits
>>2     byte&0xf0       =0xC0           \b, 128 kBits
>>2     byte&0xf0       =0xD0           \b, 144 kBits
>>2     byte&0xf0       =0xE0           \b, 160 kBits
# freq
>>2     byte&0x0C       =0x00           \b, 22.05 kHz
>>2     byte&0x0C       =0x04           \b, 24 kHz
>>2     byte&0x0C       =0x08           \b, 16 kHz
# misc
>3      byte&0xC0       =0x00           \b, Stereo
>3      byte&0xC0       =0x40           \b, JStereo
>3      byte&0xC0       =0x80           \b, Dual-Ch
>3      byte&0xC0       =0xC0           \b, Mono
#>1     byte&0x01       =0x00           \b, Error Protection
#>2     byte&0x02       =0x02           \b, Padding
#>2     byte&0x01       =0x01           \b, Private
#>3     byte&0x08       =0x08           \b, Copyright
#>3     byte&0x04       =0x04           \b, Original
#>3     byte&0x03       1               \b, Emphasis 5
#>3     byte&0x03       3               \b, Emphasis c

# FLI animation format
4	leshort		0xAF11			FLI file
>6	leshort		x			- %d frames,
>8	leshort		x			width=%d pixels,
>10	leshort		x			height=%d pixels,
>12	leshort		x			depth=%d,
>16	leshort		x			ticks/frame=%d
# FLC animation format
4	leshort		0xAF12			FLC file
>6	leshort		x			- %d frames
>8	leshort		x			width=%d pixels,
>10	leshort		x			height=%d pixels,
>12	leshort		x			depth=%d,
>16	leshort		x			ticks/frame=%d

# DL animation format
# XXX - collision with most `mips' magic
#
# I couldn't find a real magic number for these, however, this
# -appears- to work.  Note that it might catch other files, too, so be
# careful!
#
# Note that title and author appear in the two 20-byte chunks
# at decimal offsets 2 and 22, respectively, but they are XOR'ed with
# 255 (hex FF)!  The DL format is really bad.
#
#0	byte	1	DL version 1, medium format (160x100, 4 images/screen)
#>42	byte	x	- %d screens,
#>43	byte	x	%d commands
#0	byte	2	DL version 2
#>1	byte	1	- large format (320x200,1 image/screen),
#>1	byte	2	- medium format (160x100,4 images/screen),
#>1	byte	>2	- unknown format,
#>42	byte	x	%d screens,
#>43	byte	x	%d commands
# Based on empirical evidence, DL version 3 have several nulls following the
# \003.  Most of them start with non-null values at hex offset 0x34 or so.
#0	string	\3\0\0\0\0\0\0\0\0\0\0\0	DL version 3

# SGI and Apple formats
0	string		MOVI		Silicon Graphics movie file
4	string		moov		Apple QuickTime movie file (moov)
4	string		mdat		Apple QuickTime movie file (mdat)

# iso 13818 transport stream
#
# from Oskar Schirmer <[e-mail]> Feb 3, 2001 (ISO 13818.1)
# (the following is a little bit restrictive and works fine for a stream
#  that starts with PAT properly. it won't work for stream data, that is
#  cut from an input device data right in the middle, but this shouldn't
#  disturb)
# syncbyte      8 bit	0x47
# error_ind     1 bit	-
# payload_start 1 bit	1
# priority      1 bit	-
# PID          13 bit	0x0000
# scrambling    2 bit	-
# adaptfld_ctrl 2 bit	1 or 3
# conti_count   4 bit	0
0	belong&0xFF5FFF1F	0x47400010	MPEG transport stream data
>188	byte			!0x47		CORRUPTED

# ATARI ST relocatable PRG
#
# from Oskar Schirmer <[e-mail]> Feb 3, 2001
# (according to Roland Waldi, Oct 21, 1987)
# besides the magic 0x601a, the text segment size is checked to be
# not larger than 1 MB (which is a lot on ST).
0	belong&0xFFFFFFF0	0x601A0000	Atari ST M68K executable
>2	belong			x		(txt=%ld,
>6	belong			x		dat=%ld,
>10	belong			x		bss=%ld,
>14	belong			x		sym=%ld)