man3/AF_cvt_u2a.3

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    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