window.1

speech signal process tools

.\" Copyright (c) 1987,1988,1990 Entropic Speech, Inc.; All rights reserved
.\" @(#)window.1	1.8 1.8 ESI
.TH WINDOW 1\-ESPS 3/16/90
.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"
window \- windows sampled data in FEA records 
.SH "SYNOPSIS"
.B window
[
.BI \-P " params"
] [
.BI \-f " sd_field"
[
.BI \-f " power_field"
] [
.BI \-r " range"
] [
.BI \-l " window_len"
] [
.BI \-w " window_type"
] [
.BI \-x " debug_level"
]
.I "input output"
.SH "DESCRIPTION"
.PP
.I Window
accepts a FEA file \fIinput\fP containing a vector sampled-data field
in each record.  It produces a FEA file \fIoutput\fP with records
containing the results of applying a fixed window to the input
sampled-data field.  Each field of sampled data may be thought of as a
separate frame of data, such as might be produced by \fIframe\fP
(1\-\s-1ESPS\s+1).  The default name for the sampled data field in
\fIinput\fP is \fIsd\fP, and the default name for the window field in
\fIoutput\fP is \fIwind_sd\fP.  Both defaults can be changed by means
of the \fB\-f\fP option.  If the input is tagged or segment labelled,
the relevant information is copied over to the output.  If \fIinput\fP
is "\-", standard input is used for the input file.  If \fIoutput\fP
is "\-", standard input is used for the output file.
.PP
The window is computed using \fIwindow\fP (3\-\s-1ESPS\s+1).  
The fixed window length \fIwindow_len\fP must not be larger than the size
of the sampled data field.  If it is smaller, zeros are filled to the 
end of the field.  All of the first \fIwindow_len\fP elements in 
each input field are processed.  If \fIinput\fP is segment-labelled, 
\fIwindow\fP warns if any of the \fIsegment_length\fP values are 
less than \fIwindow_len\fP.  (This may be intentional, so it 
would be too verbose to identify each such frame.  They may, however,
be identified using \fIselect\fP (1\-\s-1ESPS\s+1).)  
.PP
Note that windowed FEA sampled data records can also be produced 
by \fIframe\fP (1\-\s-1ESPS\s+1).  \fIWindow\fP is intended for 
occasions when it is appropriate to defer windowing because of 
intermediate processing.  
.SH OPTIONS
.PP
The following options are supported:
.TP
.BI \-P " param" " \fR[params]\fP"
Specifies the name of the parameter file.
.TP
.BI \-r " start" : "last" "\fR [1:(last in file)]"
.TP
.BI \-r " start" :+ "nan"
In the first form, a pair of unsigned integers specifies the range
of records to be processed.
Either
.I start
or
.I last
may be omitted; then the default value is used.
If
.IR last " = " start " + " nan,
the second form (with the plus sign) specifies the same range as the first.
The \fB\-r\fP overrides the values of \fIstart\fP and \fInan\fP from 
the parameter file.  
.TP
.BI \-f " field_name" 
If this option is used once, it specifies the name of the sampled 
data field in \fIinput\fP.  If it is used twice, the second time
it specifies the name of the window field in \fIoutput\fP.  
The default names for these fields are "sd" and "wind_sd", respectively. 
.TP
.BI \-l " window_len" "\fR [0]"
Specifies the window length.  If the option is omitted, the
parameter file is consulted.  A value of 0 (from either the option or the
parameter file) indicates that the window length is the size of the sampled
data field in \fIinput\fP.  This is also the default value in case
.I window_len
is not specified either with the
.B \-l
option or in the parameter file.
.TP
.BI \-w " window_type" "\fR[RECT]"
The name of the data window to apply to the data in each frame before
computing reflection coefficients.  If the option is omitted, the parameter
file is consulted, and if no value is found there, the default used is a
rectangular window with amplitude one.  Possible window types include
rectangular ("RECT"), Hamming ("HAMMING"), and triangular ("TRIANG"); see
the window(3-ESPSsp) manual page for the complete list of supported
window types.
.IP
If the \fB\-w\fP specified
value is not a supported window type,
it is assumed to be the name of an ascii file containing
weighting function values. If no file by this name exists,
\fIwindow\fP (1\-\s-1ESPS\s+1) warns and exits.
Otherwise the file is read, the weighting values are saves, and the number
of weighting values is counted (\fIwindow_len\fP). 
In this case, the \fIwindow_len\fP value from either the \fB\-l\fP option
or the specified \fIparams\fP file is ignored.
The same rules 
about \fIwindow_len\fP as described above in \fBDESCRIPTION\fP
are in effect.
.SH "ESPS PARAMETERS"
.PP
The parameter file does not have to be present,
since all the parameters have default values.
The following parameters are read, if present, from the parameter file:
.TP
.I "sd_field_name \- string"
.IP
This is the name of the sampled data field in \fIinput\fP.
The default is "sd".  A paramter file value (if present) is overidden
by the first use of the \fB\-f\fP option.  
.TP
.I "wind_field_name \- string"
.IP
This is the name of the windowed sampled data field in \fIoutput\fP.  The
default is "wind_sd".  A paramter file value (if present) is overidden
by the second use of the \fB\-f\fP option.
.TP
.I "start \- integer"
.IP
This is the first record of \fIinput\fP to process.
The default is 1.
It is not read if the \fB\-r\fP option is used.  
.TP
.I "nan \- integer"
.IP
This is the number of records to process.  It is not read if the \fB\-r\fP
option is used.
A value of zero means all subsequent records in the file;
this is the default.
.TP
.I "window_len - integer"
.IP
The window size. This parameter is not read if the
.B \-l
option is specified.  A value of 0 indicates that the window length is the
size of the sampled data field in \fIinput\fP; this is also the default
value in case
.I window_len
is specified neither with the
.B \-l
option nor in the parameter file.
.TP
.I "window_type \- string"
The data window to apply to the data.
This parameter is not read if the command-line option
.B \-w
is specified.  If the option is omitted and if no value is found in
the parameter file, the default used is "RECT", for a rectangular
window with amplitude one.  
If the specified value is not a supported window type,
it is assumed to be a user-defined window function.
See the discussion of the \fB-w\fP option.
.PP
Remember that command line option values override parameter file
values.
.SH "ESPS COMMON"
.PP
ESPS Common processing may be disabled by setting the environment variable
USE_ESPS_COMMON to "off".  The default ESPS Common file is .espscom 
in the user's home directory.  This may be overidden by setting
the environment variable ESPSCOM to the desired path.  User feedback of
Common processing is determined by the environment variable ESPS_VERBOSE,
with 0 causing no feedback and increasing levels causing increasingly
detailed feedback.  If ESPS_VERBOSE is not defined, a default value of 3 is
assumed.
.PP
ESPS Common is not processed by 
.I window
if \fIinput\fP is 
standard input.  Otherwise, provided that the Common file is newer 
than the parameter file, and provided that the \fIfilename\fP entry in 
Common matches \fIinput\fP, the Common values for \fIstart\fP and 
\fInan\fP override those that may be present in the parameter file. 
.PP
The following items are written into the ESPS Common file 
provided that \fIoutput\fP is not <stdout>.  
.IP
.I "start \- integer"
.IP
The starting point from the input file.
.sp
.I "nan \- integer"
.IP
The number of points in the selected range.
.sp
.I "prog \- string"
.IP
This is the name of the program 
.RI ( window
in this case).
.sp
.I "filename \- string"
.IP
The name of the input file \fIinput\fP.
.SH ESPS HEADERS
.PP
The \fIoutput\fP header is a new FEA file header.  If it exists in the
input header, the generic header item \fIsrc_sf\fP is copied from
input to output.  Following the convention from \fIframe\fP
(1\-\s-1ESPS\s+1), this generic is intended to contain the sampling
rate of the original sampled data.  The generic header item
\fIstart_time\fP is written with a value computed by taking the
\fIstart_time\fP value from the header of the input file (or zero, if
such a header item doesn't exist) and adding to it the relative time
from the first record in the file to the first record processed.  The
computation of \fIstart_time\fP depends on the value of the generic
header item \fIrecord_freq\fP in the input file.  If this item is not
present, \fIstart_time\fP is just copied from the input file to the
output.
.PP
The items \fIstart\fP and \fInan\fP are rewritten (if they already
exist) to contain the starting record number and number of records
processed.  Generic header items are added for the \fIwindow_len\fP
and \fIwindow_type\fP.  As usual, the command line is added as a
comment and the header of \fIinput\fP is added as a source file to
\fIoutput\fP.  
.SH "FUTURE CHANGES"
.PP
Control over the type of the output windowed sampled data field.  
.SH "SEE ALSO"
.PP
\fIframe\fP (1\-\s-1ESPS\s+1), window (3\-\s-1ESPS\s+1), \fIpwr\fP
(1\-\s-1ESPS\s+1), FEA (5\-\s-1ESPS\s+1), \fImake_sd\fP
(1\-\s-1ESPS\s+1), \fIplotfield\fP (1\-\s-1ESPS\s+1)
.SH "WARNINGS AND DIAGNOSTICS"
.PP
.I window
will exit with an error message if any of the 
following are true: 
.I input
does not exist or is not an ESPS FEA file; 
the sampled-data field does not exist in
.I input;
the window field already exists in
.I input;
the \fIwindow_len\fP is larger than the size of the \fIinput\fP sampled
data field.
.SH "BUGS"
.PP
None known.  
.SH "AUTHOR"
.PP
Manual page and program by John Shore.