man.diff

speech signal process tools

.\" Copyright (c) 1987 Entropic Speech, Inc.; All rights reserved
.\" @(#)filtspec.1	3.10	27 Sep 1997 ESI
.TH FILTSPEC 1\-ESPS 27 Sep 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
filtspec \- compute spectral amplitude response from filter definition
.SH SYNOPSIS
.B filtspec
[
.BI \-x " debug_level"
]
[
.BI \-r " range"
]
[
.BI \-m " mode"
]
[
.BI \-n " num_freqs"
]
[
.BI \-s " sf"
]
.I input.filt
.I output.spec
.SH DESCRIPTION
The program 
.I filtspec
reads records from a \fIFEA_FILT\fP(5\-ESPS) file and produces an
\fIFEA_SPEC\fP(5-ESPS) 
file containing the amplitude response expressed in either linear 
or decibel units.
If ``\-'' is given for the input file, standard input is read.
If ``\-'' is given for the output file, standard output is written.
The output file can be plotted using the
\fIplotspec\fP(1-ESPS)
command.
.SH OPTIONS
The following options are supported.  Values in brackets are defaults.
.TP
.BI \-x " debug_level
If
.I debug_level
is non-zero,
.I filtspec
prints debugging messages and other information on the standard error output.
.TP
.BI \-r " first" : "last" "\fR [(first in file):(last in file)]"
.TP
.BI \-r " first" :+ "incr"
In the first form, a pair of unsigned integers specifies the range
of records to be processed.
Either
.I first
or
.I last
may be omitted; then the default value is used.
If
.IR last " = " first " + " incr,
the second form (with the plus sign) specifies the same range as the first.
If the specified range contains records not in the file,
.I filtspec
complains and quits.  The default is to process all of the records in the file.
.TP
.BI \-m " mode" "\fR [d]"
The string
.I mode
specifies whether the output spectral record contains the power spectrum
in linear or decibel units, or a complex frequency spectrum.  Allowable values for
.I mode
are 
.I l
for linear, 
.I d
for decibel, and
.I c
for complex.  The default for 
.I mode
is
.I d.
.TP
.BI \-n " num_freqs" "\fR [2049]"
Compute spectral values for this number of frequencies, equispaced from 0
to half the sampling frequency.  Must equal
2\v'-.35'\s-3\fIn\fR\s+3\v'.35' + 1 for some positive integer \fIn\fR.
.TP
.BI \-s " sf" "\fR [1.0]"
Specify the sampling frequency in the FEA_SPEC file header to be
.I sf.
If \fB\-s\fR is not specified on the command line,
\fIfiltspec\fR looks for a sampling frequency value in the generic
header item \fIsamp_freq\fR. If this generic header item exists,
\fIfiltspec\fR uses the value found there as the sampling frequency.
If \fIsamp_freq\fR does not
exist or is type CHAR, the default value 1.0 Hz is used.
.SH ESPS PARAMETERS
The ESPS parameter file is not used.
.SH ESPS COMMON
The ESPS Common file is not used.
.SH ESPS HEADERS
The following values are read from the header of the FEA_FILT file:
.I common.type,
.I max_num,
.I max_denom,
.I common.ndrec,
and the fields consulted by
.I allo_spec_rec.
.PP
The following parameters are written to the header of the FEA_SPEC file:
.I common.prog,
.I common.vers,
.I common.progdate.
In addition, the following standard FEA_SPEC 
generic header items are written:
.I sf 
(FLOAT),
.I freq_format 
(CODED),
.I spec_type 
(CODED),
.I num_freqs 
(LONG),
.I frame_meth 
(CODED),
and
.I contin
(CODED).
Also, the 
following generic header items are copied or updated if they exist
in the input file:
\fIstart_time\fR (DOUBLE), \fIrecord_freq\fR (DOUBLE), and \fIsrc_sf\fR
(DOUBLE).
.SH SEE ALSO
.nf
\fIplotspec\fP(1\-ESPS), \fIallo_feaspec_rec\fP(3\-ESPSu), \fIwrite_header\fP(3\-ESPSu),
\fIFEA_FILT\fP(5\-ESPS), \fIFEA_SPEC\fP(5\-ESPS), \fIESPS\fP(5\-ESPS).
.fi
.SH DIAGNOSTICS
.PP
filtspec: unknown option: 
.RI \- letter
.br
Usage: filtspec [-x debug_level][-f range][-P param_file][-n num_freqs] filt_file spec_file
.br
filtspec: number of frequencies
.I n
is not 1 plus a power of 2.
.br
filtspec: number of frequencies
.I n
exceeds 16385.
.br
filtspec: can't open
.I filename: reason
.br
filtspec: 
.I filename
is not an ESPS file
.br
filtspec: input file
.I filename
is not a FEA_FILT file.
.br
filtspec: bad range:
.I n
records in
.I filename
.br
filtspec: EOF encountered.
.SH AUTHOR
Brian Sublett. Improved for ESPS 5.0 by Derek Lin.