<?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>dcblock</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="dbfsamp.html" title="dbfsamp" /> <link rel="next" href="dcblock2.html" title="dcblock2" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">dcblock</th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="dbfsamp.html">Prev</a> </td> <th width="60%" align="center">Orchestra Opcodes and Operators</th> <td width="20%" align="right"> <a accesskey="n" href="dcblock2.html">Next</a></td> </tr> </table> <hr /> </div> <div class="refentry"> <a id="dcblock"></a> <div class="titlepage"></div> <a id="IndexDcblock" class="indexterm"></a> <div class="refnamediv"> <h2> <span class="refentrytitle">dcblock</span> </h2> <p>dcblock — A DC blocking filter. </p> </div> <div class="refsect1"> <a id="idm281472943011976"></a> <h2>Description</h2> <p> Implements the DC blocking filter </p> <div class="literallayout"> <p><br /> Y[i] = X[i] - X[i-1] + (igain * Y[i-1])<br /> </p> </div> <p> </p> <p> Based on work by Perry Cook. </p> </div> <div class="refsect1"> <a id="idm281472943009048"></a> <h2>Syntax</h2> <pre class="synopsis">ares <span class="command"><strong>dcblock</strong></span> ain [, igain]</pre> </div> <div class="refsect1"> <a id="idm281472943006808"></a> <h2>Initialization</h2> <p> <span class="emphasis"><em>igain</em></span> -- the gain of the filter, which defaults to 0.99 </p> </div> <div class="refsect1"> <a id="idm281472942964008"></a> <h2>Performance</h2> <p> <span class="emphasis"><em>ain</em></span> -- audio signal input </p> <div class="note" style="margin-left: 0.5in; margin-right: 0.5in;"> <table border="0" summary="Note"> <tr> <td rowspan="2" align="center" valign="top" width="25"> <img alt="[Note]" src="images/note.png" /> </td> <th align="left">Note</th> </tr> <tr> <td align="left" valign="top"> <p>The new <a class="link" href="dcblock2.html" title="dcblock2"><em class="citetitle">dcblock2</em></a> opcode is an improved method of removing DC from an audio signal.</p> </td> </tr> </table> </div> </div> <div class="refsect1"> <a id="idm281472942960664"></a> <h2>Examples</h2> <p> The result can be viewed in a graphical audio editor program like <span class="emphasis"><em>audacity</em></span>. <span class="emphasis"><em>audacity</em></span> is available for Linux, Windows, and the MacOS and may be downloaded from <a class="ulink" href="http://audacity.sourceforge.net/" target="_top"><em class="citetitle">http://audacity.sourceforge.net</em></a>. </p> <p> Here is an example of the dcblock opcode. It uses the file <a class="ulink" href="examples/dcblock.csd" target="_top"><em class="citetitle">dcblock.csd</em></a>, and <a class="ulink" href="examples/beats.wav" target="_top"><em class="citetitle">beats.wav</em></a>. </p> <div class="example"> <a id="idm281472942955768"></a> <p class="title"> <strong>Example 186. Example of the dcblock 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="idm281472775872088"></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> -odac <span class="c1">;;;RT audio out</span> <span class="c1">;-iadc ;;;uncomment -iadc if RT audio input is needed too</span> <span class="c1">; For Non-realtime ouput leave only the line below:</span> <span class="c1">;-o dcblock.wav -W ;;; for file output any platform</span> <span class="nt"></CsOptions></span> <span class="nt"><CsInstruments></span> <span class="vg">sr</span> <span class="o">=</span> <span class="mi">44100</span> <span class="vg">ksmps</span> <span class="o">=</span> <span class="mi">32</span> <span class="vg">nchnls</span> <span class="o">=</span> <span class="mi">2</span> <span class="kd">instr</span> <span class="nf">1</span> <span class="c1">;add DC to "beats.wav"</span> a<span class="n">sig</span> <span class="nb">soundin</span> <span class="s">"beats.wav"</span> a<span class="n">sig</span> <span class="o">=</span> a<span class="n">sig</span><span class="o">+</span><span class="mi">5000</span> <span class="c1">;adds DC of 5000</span> <span class="nb">outs</span> a<span class="n">sig</span><span class="p">,</span> a<span class="n">sig</span> <span class="kd">endin</span> <span class="kd">instr</span> <span class="nf">2</span> <span class="c1">;dcblock audio</span> a<span class="n">sig</span> <span class="nb">soundin</span> <span class="s">"beats.wav"</span> a<span class="n">sig</span> <span class="o">=</span> a<span class="n">sig</span><span class="o">+</span><span class="mi">5000</span> <span class="c1">;adds DC</span> a<span class="n">dc</span> <span class="nb">dcblock</span> a<span class="n">sig</span> <span class="c1">;remove DC again</span> <span class="nb">outs</span> a<span class="n">dc</span><span class="p">,</span> a<span class="n">dc</span> <span class="kd">endin</span> <span class="nt"></CsInstruments></span> <span class="nt"><CsScore></span> <span class="nb">i</span> <span class="mi">1</span> <span class="mi">0</span> <span class="mi">2</span> <span class="nb">i</span> <span class="mi">2</span> <span class="mi">2</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="idm281472942951496"></a> <h2>See also</h2> <p> <a class="link" href="dcblock2.html" title="dcblock2"> <em class="citetitle">dcblock2</em> </a> </p> </div> <div class="refsect1"> <a id="idm281472942949640"></a> <h2>Credits</h2> <p> </p> <table border="0" summary="Simple list" class="simplelist"> <tr> <td>Author: John ffitch</td> </tr> <tr> <td>University of Bath, Codemist Ltd.</td> </tr> <tr> <td>Bath, UK</td> </tr> </table> <p> </p> <p>New in Csound version 3.49</p> <p>February 2003: Thanks to a note from Anders Andersson, corrected the formula.</p> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="dbfsamp.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="dcblock2.html">Next</a></td> </tr> <tr> <td width="40%" align="left" valign="top">dbfsamp </td> <td width="20%" align="center"> <a accesskey="h" href="index.html">Home</a> </td> <td width="40%" align="right" valign="top"> dcblock2</td> </tr> </table> </div> </body> </html>