freebsd-nq/usr.sbin/i4b/g711conv/g711conv.1

.\"
.\" Copyright (c) 1999 Hellmuth Michaelis. All rights reserved.
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.\"	$Id: g711conv.1,v 1.3 1999/12/13 22:11:55 hm Exp $
.\"
.\" $FreeBSD$
.\"
.\"	last edit-date: [Mon Dec 13 22:54:33 1999]
.\"
.Dd March 15, 1999
.Dt G711CONV 1
.Os
.Sh NAME
.Nm g711conv
.Nd conversions according to G.711
.Sh SYNOPSIS
.Nm
.Op Fl a
.Op Fl u
.Op Fl P
.Op Fl A
.Op Fl R
.Sh DESCRIPTION
The
.Nm
utility
is part of the isdn4bsd package and is used to convert between the A-Law and
u-law formats as specified in ITU G.711. It is based on a freely available
and freely usable reference implementation done by Sun Microsystems, Inc.
.Pp
The following options are available:
.Bl -tag -width Ds
.It Fl a
Convert A-law to u-law
.It Fl u
Convert u-law to A-law
.It Fl r
Reverse bits before conversion
.It Fl R
Reverse bits after conversion
.It Fl P
Print the resulting conversion tables (as C-source) to stdout instead of
doing the actual conversion.
.El
.Sh STANDARDS
A-Law and u-Law conversions are specified in ITU Recommendation G.711.
.Pp
The reference implementation done by Sun Microsystems, Inc. is available
from http://www.itu.int/itudoc/itu-t/rec/g/g700-799/refimpl.txt
.Sh EXAMPLES
The command:
.Bd -literal -offset indent
g711conv -P -a
.Ed
.Pp
prints out the A-law to u-law conversion table as C-source to stdout.
.Pp
The command:
.Bd -literal -offset indent
cat max_headroom.ul | g711conv -u -R > /dev/i4btel0
.Ed
.Pp
converts the u-law coded voice of Max Headroom to A-law, reverses the
bits of the result and moves that to an active isdn4bsd telephone connection.
.Sh AUTHORS
The
.Nm
utility and this manpage were written by
.An Hellmuth Michaelis Aq hm@kts.org
based on the G.711 conversion reference code written by Sun Microsystems,
Inc. and code contributed to isdn4bsd by Stefan Bethke.