AF_exp_u(3)							  AF_exp_u(3)



NAME
  AF_exp_u, AF_exp_a - ULAW and	ALAW decompression tables

SYNTAX
  #include <AF/AFUtils.h>

  extern short int AF_exp_u[];

  extern short int AF_exp_a[];

  extern short int AF_cvt_u2s[];

  extern short int AF_cvt_a2s[];

  extern float AF_cvt_u2f[];

  extern float AF_cvt_a2f[];

DESCRIPTION
  These	are preexputed tables you can link with	your application.  AF_exp_u
  is indexed by	a ULAW sample and AF_exp_a is indexed by an ALAW sample.
  Each contains	a 16 bit signed	integer	value representing the corresponding
  linear value.	 Table entries are in the range	between	-8192 and +8191.

  AF_cvt_u2s and AF_cvt_a2s are	indexed	by ULAW	and ALAW samples respectively
  and contain 16 bit signed linear values scaled to the	range between -32767
  and +32767.

  AF_cvt_u2f and AF_cvt_a2f are	indexed	by ULAW	and ALAW samples respectively
  and contain single precision floating	point linear values scaled to the
  range	between	-1.0 and +1.0.

EXAMPLES
  Typical usage	is:

  unsigned char	ulaw;
  short	int lin13;
  short	int lin16;
  short	int linfloat;
  lin13	= AF_exp_u[ ulaw ];
  lin16	= AF_cvt_u2s[ ulaw ];
  linflat = AF_cvt_u2f[	ulaw ];

DIAGNOSTICS
  If you index a table with an out-of-range value you may cause	a protection
  fault	and crash your application.

SEE ALSO
  AF_comp_u(3),	AF_comp_a(3)
  AF(1)



BUGS
  If you encounter a reproducible bug, please submit a problem report to
  (af-bugs@crl.dec.com).



COPYRIGHT
  Copyright 1990-1994, Digital Equipment Corporation.
  See AF(1) for	a full statement of rights and permissions.

AUTHORS
  Tom Levergood	and Larry Stewart, Digital Cambridge Research Lab