view man/man1/conv.1 @ 0:5242703e91d3 tip

Initial checkin for AIM92 aimR8.2 (last updated May 1997).

.TH CONV 1 "1 September 1993"

.SH NAME
conv \-  Convolution.

.SH SYNTAX 
conv [options]  signal_file  impulse_response_file

.SH DESCRIPTION
The response of a linear filter to an arbitiary input signal is the
convolution of the signal with the filter's impulse response.
The `impulse_response_file' contains the impulse response which characterises the
filter, and the result of the convolution operation is the response of
that filter to the signal contained in the `signal_file'.

The `signal_file' must consist of binary 16-bit numbers (ie. shorts).
The `impulse_response_file' must consist of binary floats.
The output signal is the same length as the input signal and is written on
the stdout in binary 16-bit numbers.

If the `signal_file' consists of an impulse train, then the output should
be a repeated impulse response, ie. should be a repeated version of the
`response_file'.



.SH OPTIONS

1. length

The amount of the signal file to convolve in time units (s or ms) or in
samples (no units). Time units are converted to samples using the given
`samplerate' option. The string "max" is recognised as the remainder of
input.

2. domain

Select algorithm for convolution.  In the time domain ("domain=time") the
discrete convolution formula is applied directly as a local averaging
operation on the input signal with weights obtained by time-reversing and
shifting the impulse response. The impulse response is assumed to be zero
for all time outside the given file. In the frequency domain
("domain=frequency") the FFT of the whole input signal is multiplied by a
frequency response function (the FFT of the impulse response), and
the result inverse FFT'd.

3. scale

A scale factor for scaling the output.


.SH "SEE ALSO"
options smooth fft acf

.SH COPYRIGHT
.LP
Copyright (c) Applied Psychology Unit, Medical Research Council, 1995
.LP
Permission to use, copy, modify, and distribute this software without fee 
is hereby granted for research purposes, provided that this copyright 
notice appears in all copies and in all supporting documentation, and that 
the software is not redistributed for any fee (except for a nominal 
shipping charge). Anyone wanting to incorporate all or part of this 
software in a commercial product must obtain a license from the Medical 
Research Council.
.LP
The MRC makes no representations about the suitability of this 
software for any purpose.  It is provided "as is" without express or 
implied warranty.
.LP
THE MRC DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING 
ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL 
THE A.P.U. BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES 
OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, 
WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, 
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS 
SOFTWARE.