<?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>pdclip</title> <link rel="stylesheet" type="text/css" href="csound.css" /> <link rel="stylesheet" type="text/css" href="syntax-highlighting.css" /> <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /> <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="pcount.html" title="pcount" /> <link rel="next" href="pdhalf.html" title="pdhalf" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">pdclip</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="pcount.html">Prev</a> </td> <th width="60%" align="center">Orchestra Opcodes and Operators</th> <td width="20%" align="right"> <a accesskey="n" href="pdhalf.html">Next</a></td> </tr> </table> <hr /> </div> <div class="refentry"> <a id="pdclip"></a> <div class="titlepage"></div> <a id="IndexPdclip" class="indexterm"></a> <div class="refnamediv"> <h2> <span class="refentrytitle">pdclip</span> </h2> <p>pdclip — Performs linear clipping on an audio signal or a phasor. </p> </div> <div class="refsect1"> <a id="idm281472904492424"></a> <h2>Description</h2> <p> The <span class="emphasis"><em>pdclip</em></span> opcode allows a percentage of the input range of a signal to be clipped to fullscale. It is similar to simply multiplying the signal and limiting the range of the result, but <span class="emphasis"><em>pdclip</em></span> allows you to think about how much of the signal range is being distorted instead of the scalar factor and has a offset parameter for assymetric clipping of the signal range. <span class="emphasis"><em>pdclip</em></span> is also useful for remapping phasors for phase distortion synthesis. </p> </div> <div class="refsect1"> <a id="idm281472904417784"></a> <h2>Syntax</h2> <pre class="synopsis">aout <span class="command"><strong>pdclip</strong></span> ain, kWidth, kCenter [, ibipolar [, ifullscale]]</pre> </div> <div class="refsect1"> <a id="idm281472904415672"></a> <h2>Initialization</h2> <p> <span class="emphasis"><em>ibipolar</em></span> -- an optional parameter specifying either unipolar (0) or bipolar (1) mode. Defaults to unipolar mode. </p> <p> <span class="emphasis"><em>ifullscale</em></span> -- an optional parameter specifying the range of input and output values. The maximum will be <span class="emphasis"><em>ifullscale</em></span>. The minimum depends on the mode of operation: zero for unipolar or -<span class="emphasis"><em>ifullscale</em></span> for bipolar. Defaults to 1.0 -- you should set this parameter to the maximum expected input value. </p> </div> <div class="refsect1"> <a id="idm281472904411992"></a> <h2>Performance</h2> <p> <span class="emphasis"><em>ain</em></span> -- the input signal to be clipped. </p> <p> <span class="emphasis"><em>aout</em></span> -- the output signal. </p> <p> <span class="emphasis"><em>kWidth</em></span> -- the percentage of the signal range that is clipped (must be between 0 and 1). </p> <p> <span class="emphasis"><em>kCenter</em></span> -- an offset for shifting the unclipped window of the signal higher or lower in the range (essentially a DC offset). Values should be in the range [-1, 1] with a value of zero representing no shift (regardless of whether bipolar or unipolar mode is used). </p> <p> The <span class="emphasis"><em>pdclip</em></span> opcode performs linear clipping on the input signal ain. <span class="emphasis"><em>kWidth</em></span> specifies the percentage of the signal range that is clipped. The rest of the input range is mapped linearly from zero to ifullscale in unipolar mode and from -ifullscale to ifullscale in bipolar mode. When <span class="emphasis"><em>kCenter</em></span> is zero, equal amounts of the top and bottom of the signal range are clipped. A negative value shifts the unclipped range more towards the bottom of the input range and a positive value shifts it more towards the top. ibipolar should be 1 for bipolar operation and 0 for unipolar mode. The default is unipolar mode (ibipolar = 0). ifullscale sets the maximum amplitude of the input and output signals (defaults to 1.0). </p> <p> This amounts to waveshaping the input with the following transfer function (normalized to ifullscale=1.0 in bipolar mode): </p> <p> </p> <div class="literallayout"> <p><br /> 1| _______ x-axis is input range, y-axis is output<br /> | / <br /> | / width of clipped region is 2*kWidth<br /> -1 |/ 1 width of unclipped region is 2*(1 - kWidth)<br /> -------------------- kCenter shifts the unclipped region<br /> /| left or right (up to kWidth)<br /> / |<br /> / |<br /> ------ |-1<br /> </p> </div> <p> </p> <p> Bipolar mode can be used for direct, linear distortion of an audio signal. Alternatively, unipolar mode is useful for modifying the output of a phasor before it is used to index a function table, effectively making this a phase distortion technique. </p> </div> <div class="refsect1"> <a id="idm281472904402632"></a> <h2>See Also</h2> <p> <a class="link" href="pdhalf.html" title="pdhalf"><em class="citetitle">pdhalf</em></a>, <a class="link" href="pdhalfy.html" title="pdhalfy"><em class="citetitle">pdhalfy</em></a>, <a class="link" href="limit.html" title="limit"><em class="citetitle">limit</em></a>, <a class="link" href="clip.html" title="clip"><em class="citetitle">clip</em></a>, <a class="link" href="distort1.html" title="distort1"><em class="citetitle">distort1</em></a> </p> </div> <div class="refsect1"> <a id="idm281472904396680"></a> <h2>Examples</h2> <p> Here is an example of the pdclip opcode. It uses the file <a class="ulink" href="examples/pdclip.csd" target="_top"><em class="citetitle">pdclip.csd</em></a>. </p> <div class="example"> <a id="idm281472904394824"></a> <p class="title"> <strong>Example 680. Example of the pdclip opcode.</strong> </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> <div class="refsect1"> <a id="idm281472726554216"></a> <pre class="programlisting"> <span class="nt"><CsoundSynthesizer></span> <span class="nt"><CsOptions></span> <span class="c1">; Select audio/midi flags here according to platform</span> <span class="c1">; Audio out Audio in</span> -odac -iadc <span class="c1">;;;RT audio I/O</span> <span class="c1">; For Non-realtime ouput leave only the line below:</span> <span class="c1">; -o abs.wav -W ;;; for file output any platform</span> <span class="nt"></CsOptions></span> <span class="nt"><CsInstruments></span> <span class="c1">; test instrument for pdclip opcode</span> <span class="kd">instr</span> <span class="nf">3</span> i<span class="n">dur</span> <span class="o">=</span> <span class="nb">p3</span> i<span class="n">amp</span> <span class="o">=</span> <span class="nb">p4</span> i<span class="n">freq</span> <span class="o">=</span> <span class="nb">p5</span> i<span class="n">fn</span> <span class="o">=</span> <span class="nb">p6</span> k<span class="n">env</span> <span class="nb">linseg</span> <span class="mi">0</span><span class="p">,</span> <span class="mf">.05</span><span class="p">,</span> <span class="mf">1.0</span><span class="p">,</span> i<span class="n">dur</span> <span class="o">-</span> <span class="mf">.1</span><span class="p">,</span> <span class="mf">1.0</span><span class="p">,</span> <span class="mf">.05</span><span class="p">,</span> <span class="mi">0</span> a<span class="n">osc</span> <span class="nb">oscil</span> <span class="mf">1.0</span><span class="p">,</span> i<span class="n">freq</span><span class="p">,</span> i<span class="n">fn</span> k<span class="n">mod</span> <span class="nb">expseg</span> <span class="mf">0.00001</span><span class="p">,</span> i<span class="n">dur</span><span class="p">,</span> <span class="mf">1.0</span> a<span class="n">out</span> <span class="nb">pdclip</span> a<span class="n">osc</span><span class="p">,</span> k<span class="n">mod</span><span class="p">,</span> <span class="mf">0.0</span><span class="p">,</span> <span class="mf">1.0</span> <span class="nb">out</span> k<span class="n">env</span><span class="o">*</span>a<span class="n">out</span><span class="o">*</span>i<span class="n">amp</span> <span class="kd">endin</span> <span class="nt"></CsInstruments></span> <span class="nt"><CsScore></span> <span class="nb">f</span><span class="mi">1</span> <span class="mi">0</span> <span class="mi">16385</span> <span class="mi">10</span> <span class="mi">1</span> <span class="nb">f</span><span class="mi">2</span> <span class="mi">0</span> <span class="mi">16385</span> <span class="mi">10</span> <span class="mi">1</span> <span class="mf">.5</span> <span class="mf">.3333</span> <span class="mf">.25</span> <span class="mf">.5</span> <span class="c1">; pdclipped sine wave</span> <span class="nb">i</span><span class="mi">3</span> <span class="mi">0</span> <span class="mi">3</span> <span class="mi">15000</span> <span class="mi">440</span> <span class="mi">1</span> <span class="nb">i</span><span class="mi">3</span> <span class="o">+</span> <span class="mi">3</span> <span class="mi">15000</span> <span class="mi">330</span> <span class="mi">1</span> <span class="nb">i</span><span class="mi">3</span> <span class="o">+</span> <span class="mi">3</span> <span class="mi">15000</span> <span class="mi">220</span> <span class="mi">1</span> <span class="nb">s</span> <span class="c1">; pdclipped composite wave</span> <span class="nb">i</span><span class="mi">3</span> <span class="mi">0</span> <span class="mi">3</span> <span class="mi">15000</span> <span class="mi">440</span> <span class="mi">2</span> <span class="nb">i</span><span class="mi">3</span> <span class="o">+</span> <span class="mi">3</span> <span class="mi">15000</span> <span class="mi">330</span> <span class="mi">2</span> <span class="nb">i</span><span class="mi">3</span> <span class="o">+</span> <span class="mi">3</span> <span class="mi">15000</span> <span class="mi">220</span> <span class="mi">2</span> <span class="nb">e</span> <span class="nt"></CsScore></span> <span class="nt"></CsoundSynthesizer></span> </pre> </div> </div> </div> <p><br class="example-break" /> </p> </div> <div class="refsect1"> <a id="idm281472904390536"></a> <h2>Credits</h2> <p> </p> <table border="0" summary="Simple list" class="simplelist"> <tr> <td>Author: Anthony Kozar</td> </tr> <tr> <td>January 2008</td> </tr> </table> <p> </p> <p>New in Csound version 5.08</p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="pcount.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="pdhalf.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">pcount </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> pdhalf</td> </tr> </table> </div> </body> </html>