tiffswab.3t

tiff文件开发库

.\" $Header: /cvsroot/osrs/libtiff/man/TIFFswab.3t,v 1.1.1.1 1999/07/27 21:50:27 mike Exp $
.\"
.\" Copyright (c) 1988-1997 Sam Leffler
.\" Copyright (c) 1991-1997 Silicon Graphics, Inc.
.\"
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.\" its documentation for any purpose is hereby granted without fee, provided
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.\" IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
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.\" OF THIS SOFTWARE.
.\"
.if n .po 0
.TH SWAB 3T "December 16, 1991"
.SH NAME
TIFFReverseBits, TIFFSwabShort, TIFFSwabLong, TIFFSwabArrayOfShort, TIFFSwabArrayOfLong \- byte- and bit-swapping routines
.SH SYNOPSIS
.B "#include <tiffio.h>"
.br
.B "const unsigned char* TIFFGetBitRevTable(int reversed);"
.br
.B "void TIFFReverseBits(u_char* data, unsigned long nbytes)"
.br
.B "void TIFFSwabShort(uint16* data)"
.br
.B "void TIFFSwabLong(uint32* data)"
.br
.B "void TIFFSwabArrayOfShort(uint16* data, unsigned long nshorts)"
.br
.B "void TIFFSwabArrayOfLong(uint32* data, unsigned long nlongs)"
.SH DESCRIPTION
The following routines are used by the library to swap
16- and 32-bit data and to reverse the order of bits in bytes.
.PP
.IR TIFFSwabShort
and
.IR TIFFSwabLong
swap the bytes in a single 16-bit and 32-bit item, respectively.
.IR TIFFSwabArrayOfShort
and
.IR TIFFSwabArrayOfLong
swap the bytes in an array of 16-bit and 32-bit items, respectively.
.PP
.IR TIFFReverseBits
replaces each byte in
.I data
with the equivalent bit-reversed value.
This operation is done with a lookup table,
.I TIFFBitRevTable
which is declared public.
A second table,
.I TIFFNoBitRevTable
is also declared public; it is a lookup table that
can be used as an
.IR "identity function" ;
i.e.
.IR "TIFFNoBitRevTable[n] == n" .
.SH DIAGNOSTICS
None.
.SH "SEE ALSO"
.IR libtiff (3T),