man3/AF_mix_u.3

#

    AF_mix_u(3)							  AF_mix_u(3)

    NAME
      AF_mix_u, AF_mix_a - ULAW and	ALAW mixing tables

    SYNTAX
      #include <AF/AFUtils.h>

      extern unsigned char AF_mix_u[];

      extern unsigned char AF_mix_a[];

    DESCRIPTION
      AF_mix_u and AF_mix_a	are precomputed	tables you can link with your appli-
      cation.  Each	is indexed by a	16 bit number composed of the concatenation
      of two ULAW or ALAW samples, respectively.  Each table contains the encoded
      sample corresponding to the sum of the linearized pair of samples making up
      the index.  This is useful for mixing	two signals.

    EXAMPLES
      Typical usage	is:

      unsigned char	ulaw1, ulaw2, ulawsum;
      unsigned short index;
      /* first compose the index */
      index	= (ulaw1 << 8) | ulaw2
      /* then translate */
      ulawsum = AF_mix_u[ index ];

    DIAGNOSTICS

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

    SEE ALSO
      AF_exp_u(3), AF_exp_a(3), 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