AFMakeGainTableU(3) AFMakeGainTableU(3)
NAME
AFMakeGainTableU, AFMakeGainTableA - generate gain table
SYNTAX
#include <AF/AFUtils.h>
extern void AFMakeGainTableU(unsigned char *table, double dBgain);
DESCRIPTION
AFMakeGainTableU and AFMakeGainTableA are subroutines which generate gain
tables for ULAW and ALAW samples, respectively.
ARGUMENTS
table
is a pointer to a 256 byte table supplied by the caller. This table
is filled in by AFMakeGainTable.
dBgain
specifies the desired gain. For example, 0.0 would generate a table
that translates a sample to itself.
EXAMPLES
Typical usage is:
unsigned char table[256];
unsigned char input, output;
/* first generate a 5 dB gain table */
AFMakeGainTableU(&table[0], 5.0);
/* then translate */
output = table[ input ];
DIAGNOSTICS
If you index the table with an out-of-range value you may cause a protec-
tion fault and crash your application.
SEE ALSO
AF_gain_table_u(3), AF_gain_table_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
Larry Stewart, Digital Cambridge Research Lab