<?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>loopseg</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="loop_lt.html" title="loop_lt" />
<link rel="next" href="loopsegp.html" title="loopsegp" />
</head>
<body>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">loopseg</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="loop_lt.html">Prev</a> </td>
<th width="60%" align="center">Orchestra Opcodes and Operators</th>
<td width="20%" align="right"> <a accesskey="n" href="loopsegp.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="refentry">
<a id="loopseg"></a>
<div class="titlepage"></div>
<a id="IndexLoopseg" class="indexterm"></a>
<div class="refnamediv">
<h2>
<span class="refentrytitle">loopseg</span>
</h2>
<p>loopseg —
Generate control signal consisting of linear segments delimited by two or more specified points.
</p>
</div>
<div class="refsect1">
<a id="idm281472918907864"></a>
<h2>Description</h2>
<p>
Generate control signal consisting of linear segments delimited by two or more specified points. The entire envelope is looped at <span class="emphasis"><em>kfreq</em></span> rate. Each parameter can be varied at k-rate.
</p>
</div>
<div class="refsect1">
<a id="idm281472918863896"></a>
<h2>Syntax</h2>
<pre class="synopsis">ksig <span class="command"><strong>loopseg</strong></span> kfreq, ktrig, iphase, kvalue0, ktime0 [, kvalue1] [, ktime1] \
[, kvalue2] [, ktime2][...]</pre>
</div>
<div class="refsect1">
<a id="idm281472918861640"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>iphase</em></span> -- A value between 0 and 1 to say
where to start the loop. Zero, the commonest value, indicates
the beginning.
</p>
</div>
<div class="refsect1">
<a id="idm281472918859896"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>ksig</em></span> -- Output signal.
</p>
<p>
<span class="emphasis"><em>kfreq</em></span> -- Repeat rate in Hz or fraction of Hz.
</p>
<p>
<span class="emphasis"><em>ktrig</em></span> -- If non-zero, retriggers the envelope from start (see <a class="link" href="trigger.html" title="trigger"><em class="citetitle">trigger opcode</em></a>), before the envelope cycle is completed.
</p>
<p>
<span class="emphasis"><em>kvalue0...kvalueN</em></span> -- Values of points
</p>
<p>
<span class="emphasis"><em>ktime0...ktimeN</em></span> -- Times between points; expressed in fractions of a cycle (see below). The final time designates a ramp between the final value and the first value.
</p>
<p>
<span class="emphasis"><em>loopseg</em></span> opcode is similar to <a class="link" href="linseg.html" title="linseg"><em class="citetitle">linseg</em></a>, but the entire envelope is looped at <span class="emphasis"><em>kfreq</em></span> rate. Notice that times are not expressed in seconds but in fraction of a cycle. Actually each duration represent is proportional to the other, and the entire cycle duration is proportional to the sum of all duration values.
</p>
<p>
The sum of all duration is then rescaled according to <span class="emphasis"><em>kfreq</em></span> argument. For example, considering an envelope made up of 3 segments, each segment having 100 as duration value, their sum will be 300. This value represents the total duration of the envelope, and is actually divided into 3 equal parts, a part for each segment.
</p>
<p>
Actually, the real envelope duration in seconds is determined by <span class="emphasis"><em>kfreq</em></span>. Again, if the envelope is made up of 3 segments, but this time the first and last segments have a duration of 50, whereas the central segment has a duration of 100 again, their sum will be 200. This time 200 represent the total duration of the 3 segments, so the central segment will be twice as long as the other segments.
</p>
<p>
All parameters can be varied at k-rate. Negative frequency values are allowed, reading the envelope backward. <span class="emphasis"><em>ktime0</em></span> should always be set to 0, except if the user wants some special effect.
</p>
</div>
<div class="refsect1">
<a id="idm281472918848216"></a>
<h2>Examples</h2>
<p>
Here is an example of the loopseg opcode. It uses the file <a class="ulink" href="examples/loopseg.csd" target="_top"><em class="citetitle">loopseg.csd</em></a>.
</p>
<div class="example">
<a id="idm281472918846360"></a>
<p class="title">
<strong>Example 483. Example of the loopseg 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="idm281472745692536"></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">;;;realtime audio out</span>
<span class="c1">;-iadc ;;;uncomment -iadc if realtime audio input is needed too</span>
<span class="c1">; For Non-realtime ouput leave only the line below:</span>
<span class="c1">; -o loopseg.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="vg">0dbfs</span> <span class="o">=</span> <span class="mi">1</span>
<span class="kd">instr</span> <span class="nf">1</span>
k<span class="n">freq</span> <span class="nb">init</span> <span class="nb">p4</span> <span class="c1">; frequency of loop repetition</span>
i<span class="n">frac</span> <span class="o">=</span> <span class="nb">p5</span> <span class="c1">; frequency ratio of restart triggers</span>
k<span class="n">trig</span> <span class="nb">metro</span> k<span class="n">freq</span> <span class="o">*</span> i<span class="n">frac</span> <span class="c1">; triggers to restart loop</span>
i<span class="n">phase</span> <span class="o">=</span> <span class="mi">0</span> <span class="c1">; initial phase</span>
<span class="c1">; loop of note values (some glissandi)</span>
<span class="c1">; val dur val dur etc...</span>
k<span class="n">note</span> <span class="nb">loopseg</span> k<span class="n">freq</span><span class="p">,</span> k<span class="n">trig</span><span class="p">,</span> i<span class="n">phase</span><span class="p">,</span> <span class="mi">40</span><span class="p">,</span> <span class="mi">1</span><span class="p">,</span> <span class="mi">40</span><span class="p">,</span> <span class="mi">0</span><span class="p">,</span> <span class="mi">43</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">43</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">49</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">48</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> \
<span class="mi">47</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">47</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">46</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">46</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">46</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">47</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">49</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">49</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">43</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">43</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">46</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">46</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">40</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">39</span><span class="p">,</span><span class="mi">0</span>
<span class="c1">; loop of filter cutoff values (oct format). This loop, half speed of note loop.</span>
k<span class="n">cfoct</span> <span class="nb">loopseg</span> k<span class="n">freq</span><span class="o">*</span><span class="mf">0.5</span><span class="p">,</span> k<span class="n">trig</span><span class="p">,</span> i<span class="n">phase</span><span class="p">,</span> <span class="mi">11</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">12</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">13</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> \
<span class="mf">11.5</span><span class="p">,</span><span class="mi">3</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mf">12.5</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mi">13</span><span class="p">,</span><span class="mi">2</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">0</span><span class="p">,</span> <span class="mf">12.5</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">4</span><span class="p">,</span><span class="mi">0</span>
k<span class="n">env</span> <span class="nb">linseg</span> <span class="mi">0</span><span class="p">,</span><span class="mf">0.01</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="nb">p3</span><span class="o">-</span><span class="mf">5.01</span><span class="p">,</span><span class="mi">1</span><span class="p">,</span><span class="mi">5</span><span class="p">,</span><span class="mi">0</span>
i<span class="n">oct</span> <span class="o">=</span> <span class="nb">int</span><span class="p">((</span><span class="nb">rnd</span><span class="p">(</span><span class="mf">0.999</span><span class="p">)</span><span class="o">*</span><span class="mi">4</span><span class="p">)</span><span class="o">-</span><span class="mi">2</span><span class="p">)</span> <span class="c1">; random value either -1, 0 or 1</span>
a<span class="n">sig</span> <span class="nb">vco2</span> <span class="mf">0.2</span><span class="o">*</span>k<span class="n">env</span><span class="p">,</span><span class="nb">cpsmidinn</span><span class="p">(</span>k<span class="n">note</span><span class="p">)</span><span class="o">*</span><span class="nb">octave</span><span class="p">(</span>i<span class="n">oct</span><span class="p">),</span><span class="mi">0</span> <span class="c1">; sawtooth</span>
a<span class="n">sig</span> <span class="nb">moogladder</span> a<span class="n">sig</span><span class="p">,</span><span class="nb">cpsoct</span><span class="p">(</span>k<span class="n">cfoct</span><span class="p">),</span><span class="nb">rnd</span><span class="p">(</span><span class="mf">0.6</span><span class="p">)</span> <span class="c1">; filter sawtooth</span>
a<span class="n">L</span><span class="p">,</span>a<span class="n">R</span> <span class="nb">pan2</span> a<span class="n">sig</span><span class="p">,</span><span class="nb">rnd</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span> <span class="c1">; random static pan location</span>
<span class="nb">outs</span> a<span class="n">L</span><span class="p">,</span> a<span class="n">R</span>
<span class="kd">endin</span>
<span class="nt"></CsInstruments></span>
<span class="nt"><CsScore></span>
<span class="c1">; 4 layers, each with a different frequency of loop repetition (p4),</span>
<span class="c1">; frequency ratio of restart triggers (p5) and pan position (p6).</span>
<span class="nb">i</span> <span class="mi">1</span> <span class="mi">0</span> <span class="mi">30</span> <span class="mf">0.5</span> <span class="p">[</span><span class="mi">11</span><span class="o">/</span><span class="mi">19</span><span class="p">]</span>
<span class="nb">i</span> <span class="mi">1</span> <span class="mi">6</span> <span class="mi">30</span> <span class="mf">0.25</span> <span class="p">[</span><span class="mi">11</span><span class="o">/</span><span class="mi">13</span><span class="p">]</span>
<span class="nb">i</span> <span class="mi">1</span> <span class="mi">12</span> <span class="mi">30</span> <span class="mf">0.125</span> <span class="p">[</span><span class="mi">11</span><span class="o">/</span><span class="mi">16</span><span class="p">]</span>
<span class="nb">i</span> <span class="mi">1</span> <span class="mi">18</span> <span class="mi">30</span> <span class="mi">1</span> <span class="p">[</span><span class="mi">11</span><span class="o">/</span><span class="mi">12</span><span class="p">]</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="idm281472918842072"></a>
<h2>See Also</h2>
<p>
<a class="link" href="lpshold.html" title="lpshold"><em class="citetitle">lpshold</em></a>
<a class="link" href="loopxseg.html" title="loopxseg"><em class="citetitle">loopxseg</em></a>
</p>
</div>
<div class="refsect1">
<a id="idm281472918839096"></a>
<h2>Credits</h2>
<p>Author: Gabriel Maldonado</p>
<p>New in Version 4.13</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="loop_lt.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="loopsegp.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">loop_lt </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> loopsegp</td>
</tr>
</table>
</div>
</body>
</html>
distrib
>
Mageia
>
7
>
armv7hl
>
media
>
core-release
>
by-pkgid
>
5fcfcb7517038d1f44ab4e478e6e61fa
>
files
>
2386
