<?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>fold</title>
<link rel="stylesheet" href="csound.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2" />
<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="fog.html" title="fog" />
<link rel="next" href="follow.html" title="follow" />
</head>
<body>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">fold</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="fog.html">Prev</a> </td>
<th width="60%" align="center">Orchestra Opcodes and Operators</th>
<td width="20%" align="right"> <a accesskey="n" href="follow.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="refentry" title="fold">
<a id="fold"></a>
<div class="titlepage"></div>
<a id="IndexFold" class="indexterm"></a>
<div class="refnamediv">
<h2>
<span class="refentrytitle">fold</span>
</h2>
<p>fold —
Adds artificial foldover to an audio signal.
</p>
</div>
<div class="refsect1" title="Description">
<a id="id2912548"></a>
<h2>Description</h2>
<p>
Adds artificial foldover to an audio signal.
</p>
</div>
<div class="refsect1" title="Syntax">
<a id="id2912561"></a>
<h2>Syntax</h2>
<pre class="synopsis">ares <span class="command"><strong>fold</strong></span> asig, kincr</pre>
</div>
<div class="refsect1" title="Performance">
<a id="id2912619"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>asig</em></span> -- input signal
</p>
<p>
<span class="emphasis"><em>kincr</em></span> -- amount of foldover expressed in multiple of sampling rate. Must be >= 1
</p>
<p>
<span class="emphasis"><em>fold</em></span> is an opcode which creates artificial foldover. For example, when <span class="emphasis"><em>kincr</em></span> is equal to 1 with sr=44100, no foldover is added. When <span class="emphasis"><em>kincr</em></span> is set to 2, the foldover is equivalent to a downsampling to 22050, when it is set to 4, to 11025 etc. Fractional values of <span class="emphasis"><em>kincr</em></span> are possible, allowing a continuous variation of foldover amount. This can be used for a wide range of special effects.
</p>
</div>
<div class="refsect1" title="Examples">
<a id="id2912665"></a>
<h2>Examples</h2>
<p>
Here is an example of the fold opcode. It uses the file <a class="ulink" href="examples/fold.csd" target="_top"><em class="citetitle">fold.csd</em></a>.
</p>
<div class="example">
<a id="id2913642"></a>
<p class="title">
<b>Example 257. Example of the fold opcode.</b>
</p>
<div class="example-contents">
<p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
<pre class="programlisting">
<span class="csdtag"><CsoundSynthesizer></span>
<span class="csdtag"><CsOptions></span>
<span class="comment">; Select audio/midi flags here according to platform</span>
<span class="comment">; Audio out Audio in No messages</span>
-odac -iadc -d <span class="comment">;;;RT audio I/O</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o fold.wav -W ;;; for file output any platform</span>
<span class="csdtag"></CsOptions></span>
<span class="csdtag"><CsInstruments></span>
<span class="comment">; Initialize the global variables.</span>
<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">kr</span> <span class="op">=</span> 4410
<span class="ohdr">ksmps</span> <span class="op">=</span> 10
<span class="ohdr">nchnls</span> <span class="op">=</span> 1
<span class="comment">; Instrument #1.</span>
<span class="oblock">instr</span> 1
<span class="comment">; Use an ordinary sine wave.</span>
asig <span class="opc">oscils</span> 30000, 100, 1
<span class="comment">; Vary the fold-over amount from 1 to 200.</span>
kincr <span class="opc">line</span> 1, p3, 200
a1 <span class="opc">fold</span> asig, kincr
<span class="opc">out</span> a1
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="comment">; Play Instrument #1 for four seconds.</span>
<span class="stamnt">i</span> 1 0 4
<span class="stamnt">e</span>
<span class="csdtag"></CsScore></span>
<span class="csdtag"></CsoundSynthesizer></span>
</pre>
</div>
</div>
<p><br class="example-break" />
</p>
</div>
<div class="refsect1" title="Credits">
<a id="id2913681"></a>
<h2>Credits</h2>
<p>
</p>
<table border="0" summary="Simple list" class="simplelist">
<tr>
<td>Author: Gabriel Maldonado</td>
</tr>
<tr>
<td>Italy</td>
</tr>
<tr>
<td>1999</td>
</tr>
</table>
<p>
</p>
<p>New in Csound version 3.56</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="fog.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="follow.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">fog </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> follow</td>
</tr>
</table>
</div>
</body>
</html>
