SWAB(3T)

NAME
TIFFReverseBits, TIFFSwabShort, TIFFSwabLong, TIFFSwabArrayOfShort, TIFFSwabArrayOfLong - byte- and bit-swapping routines

SYNOPSIS
#include <tiffio.h>
extern unsigned char TIFFBitRevTable[256];
extern unsigned char TIFFNoBitRevTable[256];
void TIFFReverseBits(u_char* data, int nbytes)
void TIFFSwabShort(u_short* data)
void TIFFSwabLong(u_long* data)
void TIFFSwabArrayOfShort(u_short* data, int nshorts)
void TIFFSwabArrayOfLong(u_short* data, int nlongs)

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.

TIFFSwabShort() and TIFFSwabLong() swap the bytes in a single 16-bit and 32-bit item, respectively. TIFFSwabArrayOfShort() and TIFFSwabArrayOfLong() swap the bytes in an array of 16-bit and 32-bit items, respectively.

TIFFReverseBits() replaces each byte in data with the equivalent bit-reversed value. This operation is done with a lookup table, TIFFBitRevTable which is declared public. A second table, TIFFNoBitRevTable is also declared public; it is a lookup table that can be used as an identity function; i.e. TIFFNoBitRevTable[n] == n.

DIAGNOSTICS
None.

SEE ALSO
intro(3T),