<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>specfilt</title> <link rel="stylesheet" type="text/css" href="csound.css" /> <meta name="generator" content="DocBook XSL Stylesheets V1.76.1" /> <link rel="home" href="index.html" title="The Canonical Csound Reference Manual" /> <link rel="up" href="OpcodesTop.html" title="Orchestra Opcodes and Operators" /> <link rel="prev" href="specdisp.html" title="specdisp" /> <link rel="next" href="spechist.html" title="spechist" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">specfilt</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="specdisp.html">Prev</a> </td> <th width="60%" align="center">Orchestra Opcodes and Operators</th> <td width="20%" align="right"> <a accesskey="n" href="spechist.html">Next</a></td> </tr> </table> <hr /> </div> <div class="refentry" title="specfilt"> <a id="specfilt"></a> <div class="titlepage"></div> <a id="IndexSpecfilt" class="indexterm"></a> <div class="refnamediv"> <h2> <span class="refentrytitle">specfilt</span> </h2> <p>specfilt — Filters each channel of an input spectrum. </p> </div> <div class="refsect1" title="Description"> <a id="idp44810672"></a> <h2>Description</h2> <p> Filters each channel of an input spectrum. </p> </div> <div class="refsect1" title="Syntax"> <a id="idp44811328"></a> <h2>Syntax</h2> <pre class="synopsis">wsig <span class="command"><strong>specfilt</strong></span> wsigin, ifhtim</pre> </div> <div class="refsect1" title="Initialization"> <a id="idp44821200"></a> <h2>Initialization</h2> <p> <span class="emphasis"><em>ifhtim</em></span> -- half-time constant. </p> </div> <div class="refsect1" title="Performance"> <a id="idp44822048"></a> <h2>Performance</h2> <p> <span class="emphasis"><em>wsigin</em></span> -- the input spectrum. </p> <p> Filters each channel of an input spectrum. At each new frame of <span class="emphasis"><em>wsigin</em></span>, each magnitude value is injected into a 1st-order lowpass recursive filter, whose half-time constant has been initially set by sampling the ftable <span class="emphasis"><em>ifhtim</em></span> across the (logarithmic) frequency space of the input spectrum. This unit effectively applies a <span class="emphasis"><em>persistence</em></span> factor to the data occurring in each spectral channel, and is useful for simulating the <span class="emphasis"><em>energy integration</em></span> that occurs during auditory perception. It may also be used as a time-attenuated running <span class="emphasis"><em>histogram</em></span> of the spectral distribution. </p> </div> <div class="refsect1" title="Examples"> <a id="idp44824704"></a> <h2>Examples</h2> <p> </p> <div class="informalexample"> <pre class="programlisting"> wsig2 <span class="opc">specdiff</span> wsig1 <span class="comment">; sense onsets</span> wsig3 <span class="opc">specfilt</span> wsig2, 2 <span class="comment">; absorb slowly</span> <span class="opc">specdisp</span> wsig2, 0.1 <span class="comment">; & display both spectra</span> <span class="opc">specdisp</span> wsig3, 0.1</pre> </div> <p> </p> </div> <div class="refsect1" title="See Also"> <a id="idp44914616"></a> <h2>See Also</h2> <p> <a class="link" href="specaddm.html" title="specaddm"><em class="citetitle">specaddm</em></a>, <a class="link" href="specdiff.html" title="specdiff"><em class="citetitle">specdiff</em></a>, <a class="link" href="spechist.html" title="spechist"><em class="citetitle">spechist</em></a>, <a class="link" href="specscal.html" title="specscal"><em class="citetitle">specscal</em></a> </p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="specdisp.html">Prev</a> </td> <td width="20%" align="center"> <a accesskey="u" href="OpcodesTop.html">Up</a> </td> <td width="40%" align="right"> <a accesskey="n" href="spechist.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">specdisp </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> spechist</td> </tr> </table> </div> </body> </html>