103 lines
2 KiB
Python
103 lines
2 KiB
Python
#
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# The Python Imaging Library.
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# $Id$
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#
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# Binary input/output support routines.
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#
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# Copyright (c) 1997-2003 by Secret Labs AB
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# Copyright (c) 1995-2003 by Fredrik Lundh
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# Copyright (c) 2012 by Brian Crowell
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#
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# See the README file for information on usage and redistribution.
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#
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"""Binary input/output support routines."""
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from struct import pack, unpack_from
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def i8(c):
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return c if c.__class__ is int else c[0]
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def o8(i):
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return bytes((i & 255,))
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# Input, le = little endian, be = big endian
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def i16le(c, o=0):
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"""
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Converts a 2-bytes (16 bits) string to an unsigned integer.
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:param c: string containing bytes to convert
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:param o: offset of bytes to convert in string
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"""
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return unpack_from("<H", c, o)[0]
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def si16le(c, o=0):
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"""
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Converts a 2-bytes (16 bits) string to a signed integer.
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:param c: string containing bytes to convert
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:param o: offset of bytes to convert in string
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"""
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return unpack_from("<h", c, o)[0]
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def si16be(c, o=0):
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"""
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Converts a 2-bytes (16 bits) string to a signed integer, big endian.
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:param c: string containing bytes to convert
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:param o: offset of bytes to convert in string
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"""
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return unpack_from(">h", c, o)[0]
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def i32le(c, o=0):
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"""
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Converts a 4-bytes (32 bits) string to an unsigned integer.
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:param c: string containing bytes to convert
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:param o: offset of bytes to convert in string
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"""
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return unpack_from("<I", c, o)[0]
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def si32le(c, o=0):
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"""
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Converts a 4-bytes (32 bits) string to a signed integer.
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:param c: string containing bytes to convert
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:param o: offset of bytes to convert in string
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"""
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return unpack_from("<i", c, o)[0]
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def i16be(c, o=0):
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return unpack_from(">H", c, o)[0]
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def i32be(c, o=0):
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return unpack_from(">I", c, o)[0]
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# Output, le = little endian, be = big endian
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def o16le(i):
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return pack("<H", i)
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def o32le(i):
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return pack("<I", i)
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def o16be(i):
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return pack(">H", i)
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def o32be(i):
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return pack(">I", i)
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