autopefrc.3

speech signal process tools

.\" Copyright (c) 1987 Entropic Speech, Inc.; All rights reserved
./" @(#)autopefrc.3	1.5 06 May 1997 ESI
.TH AUTO_PEF_RC 3\-ESPSsp 06 May 1997
.ds ]W "\fI\s+4\ze\h'0.05'e\s-4\v'-0.4m'\fP\(*p\v'0.4m'\ Entropic Speech, Inc.
.SH NAME
auto_pefrc \- convert autocorrelations to prediction error filter and
reflection coefficients
.PP
pef_autorc \- convert prediction error filter coefficients to
autocorrelations and reflection coefficients
.PP
rc_autopef \- convert reflection coefficients to autocorrelations and
prediction error filter coefficients
.SH SYNOPSIS
.ft B
int 
.br
auto_pefrc (order, auto, pef, rc)
.br
int order;
.br 
double *pef, *auto, *rc;
.sp
.br
int 
.br
pef_autorc (order, pef, auto, rc)
.br
int order;
.br 
double *pef, *auto, *rc;
.sp
.br
int 
.br
rc_autopef (order, rc, auto, pef)
.br
int order;
.br 
double *pef, *auto, *rc;
.SH DESCRIPTION
.PP
Each function transforms a set of coefficients that
contain spectral information 
(either autocorrelations, prediction error filter coefficients, or
reflection coefficients) into the other two coefficient sets.
.PP
.I auto_pefrc 
transforms 
.I order 
+ 1 autocorrelations into
the mean square residual (stored in 
.I pef[0]
and 
\fIrc[0]\fR)
and
.I order
prediction error filter (\fIpef\fR)
coefficients and 
.I order 
reflection coefficients 
(\fIrc\fR).
The prediction error filter coefficients and the reflection coefficients
are stored in the 1st through 
.I order 
positions of
.I pef[]
and 
.I rc[],
respectively.
.PP
.I pef_autorc
transforms 
the mean square residual 
(stored in 
\fIpef[0]\fR)
and 
.I order 
prediction error filter coefficients
into 
.I order 
+ 1 autocorrelations 
(stored in positions 0 through 
\fIorder\fR)
and 
.I order
reflection coefficients (stored
in position  1 through
\fIorder\fR).
.PP
.I rc_autopef
transforms the mean square residual
(stored in 
\fIrc[0]\fR) and
.I order 
reflection coefficients
into
.I order
+ 1  autocorrelations 
(stored in positions 0 through
\fIorder\fR) and 
\fIorder\fR
prediction error filter coefficients
(stored in positions 1 through
\fIorder\fR).
.SH DIAGNOSTICS
.PP
All functions return  0 if no problem
is discovered in the input data or in the parameter transformation.
If the mean square residual <=0, then \-1 is returned;
if any reflection coefficient >= 1., then
the index of the invalid coefficient is returned.
.SH SEE ALSO
refl_to_filter(3-ESPSsp), get_atal(3-ESPSsp), refl_to_auto(3-ESPSsp)
.SH WARNINGS
Remember, the calling routine must allocate memory for 
.I order
+ 1 elements for each of the three pointers
.I *auto, *pef, 
and
.I *rc.
.SH AUTHOR
Code by John P. Burg; ESPS modification by David Burton;
manual page by David Burton.