<?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>grain2</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="grain.html" title="grain" />
<link rel="next" href="grain3.html" title="grain3" />
</head>
<body>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">grain2</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="grain.html">Prev</a> </td>
<th width="60%" align="center">Orchestra Opcodes and Operators</th>
<td width="20%" align="right"> <a accesskey="n" href="grain3.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="refentry" title="grain2">
<a id="grain2"></a>
<div class="titlepage"></div>
<a id="IndexGrain2" class="indexterm"></a>
<div class="refnamediv">
<h2>
<span class="refentrytitle">grain2</span>
</h2>
<p>grain2 —
Easy-to-use granular synthesis texture generator.
</p>
</div>
<div class="refsect1" title="Description">
<a id="idp25526704"></a>
<h2>Description</h2>
<p>
Generate granular synthesis textures. <span class="emphasis"><em>grain2</em></span> is simpler to use, but <a class="link" href="grain3.html" title="grain3"><em class="citetitle">grain3</em></a> offers more control.
</p>
</div>
<div class="refsect1" title="Syntax">
<a id="idp25528016"></a>
<h2>Syntax</h2>
<pre class="synopsis">ares <span class="command"><strong>grain2</strong></span> kcps, kfmd, kgdur, iovrlp, kfn, iwfn [, irpow] \
[, iseed] [, imode]</pre>
</div>
<div class="refsect1" title="Initialization">
<a id="idp25529288"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>iovrlp</em></span> -- (fixed) number of overlapping grains.
</p>
<p>
<span class="emphasis"><em>iwfn</em></span> -- function table containing window waveform (Use <a class="link" href="GEN20.html" title="GEN20">GEN20</a> to calculate <span class="emphasis"><em>iwfn</em></span>).
</p>
<p>
<span class="emphasis"><em>irpow</em></span> (optional, default=0) -- this value controls the distribution of grain frequency variation. If <span class="emphasis"><em>irpow</em></span> is positive, the random distribution (<span class="emphasis"><em>x</em></span> is in the range -1 to 1) is </p>
<div class="literallayout">
<p>abs(x) ^ ((1 / irpow) - 1);</p>
</div>
<p> for negative <span class="emphasis"><em>irpow</em></span> values, it is </p>
<div class="literallayout">
<p>(1 - abs(x)) ^ ((-1 / irpow) - 1)</p>
</div>
<p>Setting <span class="emphasis"><em>irpow</em></span> to -1, 0, or 1 will result in uniform distribution (this is also faster to calculate). The image below shows some examples for <span class="emphasis"><em>irpow</em></span>. The default value of <span class="emphasis"><em>irpow</em></span> is 0.
</p>
<p>
</p>
<div class="mediaobject">
<img src="images/grain2_rand-448x289.png" alt="[A graph of distributions for different values of irpow.]" />
<div class="caption">
<p>A graph of distributions for different values of <span class="emphasis"><em>irpow</em></span>.</p>
</div>
</div>
<p>
</p>
<p>
<span class="emphasis"><em>iseed</em></span> (optional, default=0) -- seed value for random number generator (positive integer in the range 1 to 2147483646 (2<sup>31</sup> - 2)). Zero or negative value seeds from current time (this is also the default).
</p>
<p>
<span class="emphasis"><em>imode</em></span> (optional default=0) -- sum of the following values:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" type="disc">
<li class="listitem">
<p><span class="emphasis"><em>8:</em></span> interpolate window waveform (slower).</p>
</li>
<li class="listitem">
<p><span class="emphasis"><em>4:</em></span> do not interpolate grain waveform (fast, but lower quality).</p>
</li>
<li class="listitem">
<p><span class="emphasis"><em>2:</em></span> grain frequency is continuously modified by <span class="emphasis"><em>kcps</em></span> and <span class="emphasis"><em>kfmd</em></span> (by default, each grain keeps the frequency it was launched with). This may be slower at high control rates.</p>
</li>
<li class="listitem">
<p><span class="emphasis"><em>1:</em></span> skip initialization.</p>
</li>
</ul>
</div>
<p>
</p>
</div>
<div class="refsect1" title="Performance">
<a id="idp25540824"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>ares</em></span> -- output signal.
</p>
<p>
<span class="emphasis"><em>kcps</em></span> -- grain frequency in Hz.
</p>
<p>
<span class="emphasis"><em>kfmd</em></span> -- random variation (bipolar) in grain frequency in Hz.
</p>
<p>
<span class="emphasis"><em>kgdur</em></span> -- grain duration in seconds. <span class="emphasis"><em>kgdur</em></span> also controls the duration of already active grains (actually the speed at which the window function is read). This behavior does not depend on the <span class="emphasis"><em>imode</em></span> flags.
</p>
<p>
<span class="emphasis"><em>kfn</em></span> -- function table containing grain waveform. Table number can be changed at k-rate (this is useful to select from a set of band-limited tables generated by <a class="link" href="GEN30.html" title="GEN30">GEN30</a>, to avoid aliasing).
</p>
<div class="note" title="Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<table border="0" summary="Note: 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>
<span class="emphasis"><em>grain2</em></span> internally uses the same random number generator as <span class="emphasis"><em>rnd31</em></span>. So reading <a class="link" href="rnd31.html" title="rnd31"><em class="citetitle">its documentation</em></a> is also recommended.
</p>
</td>
</tr>
</table>
</div>
</div>
<div class="refsect1" title="Examples">
<a id="idp25546560"></a>
<h2>Examples</h2>
<p>
Here is an example of the grain2 opcode. It uses the file <a class="ulink" href="examples/grain2.csd" target="_top"><em class="citetitle">grain2.csd</em></a>.
</p>
<div class="example">
<a id="idp25547536"></a>
<p class="title">
<strong>Example 330. Example of the grain2 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>
<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 grain2.wav -W ;;; for file output any platform</span>
<span class="csdtag"></CsOptions></span>
<span class="csdtag"><CsInstruments></span>
<span class="ohdr">sr</span> <span class="op">=</span> 48000
<span class="ohdr">kr</span> <span class="op">=</span> 750
<span class="ohdr">ksmps</span> <span class="op">=</span> 64
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="op">/</span><span class="op">*</span> square wave <span class="op">*</span><span class="op">/</span>
i_ <span class="ohdr">ftgen</span> 1, 0, 4096, 7, 1, 2048, 1, 0, <span class="op">-</span>1, 2048, <span class="op">-</span>1
<span class="op">/</span><span class="op">*</span> window <span class="op">*</span><span class="op">/</span>
i_ <span class="ohdr">ftgen</span> 2, 0, 16384, 7, 0, 4096, 1, 4096, 0.3333, 8192, 0
<span class="op">/</span><span class="op">*</span> sine wave <span class="op">*</span><span class="op">/</span>
i_ <span class="ohdr">ftgen</span> 3, 0, 1024, 10, 1
<span class="op">/</span><span class="op">*</span> room parameters <span class="op">*</span><span class="op">/</span>
i_ <span class="ohdr">ftgen</span> 7, 0, 64, <span class="op">-</span>2, 4, 50, <span class="op">-</span>1, <span class="op">-</span>1, <span class="op">-</span>1, 11, \
1, 26.833, 0.05, 0.85, 10000, 0.8, 0.5, 2, \
1, 1.753, 0.05, 0.85, 5000, 0.8, 0.5, 2, \
1, 39.451, 0.05, 0.85, 7000, 0.8, 0.5, 2, \
1, 33.503, 0.05, 0.85, 7000, 0.8, 0.5, 2, \
1, 36.151, 0.05, 0.85, 7000, 0.8, 0.5, 2, \
1, 29.633, 0.05, 0.85, 7000, 0.8, 0.5, 2
ga01 <span class="opc">init</span> 0
<span class="op">/</span><span class="op">*</span> generate bandlimited square waves <span class="op">*</span><span class="op">/</span>
i0 <span class="op">=</span> 0
<span class="olabel">loop1</span><span class="op">:</span>
imaxh <span class="op">=</span> <span class="ohdr">sr</span> <span class="op">/</span> (2 <span class="op">*</span> 440.0 <span class="op">*</span> <span class="opc">exp</span> (<span class="opc">log</span>(2.0) <span class="op">*</span> (i0 <span class="op">-</span> 69) <span class="op">/</span> 12))
i_ <span class="ohdr">ftgen</span> i0 <span class="op">+</span> 256, 0, 4096, <span class="op">-</span>30, 1, 1, imaxh
i0 <span class="op">=</span> i0 <span class="op">+</span> 1
<span class="octrl">if</span> (i0 <span class="op"><</span> 127.5) <span class="octrl">igoto</span> <span class="olabel">loop1</span>
<span class="oblock">instr</span> 1
p3 <span class="op">=</span> p3 <span class="op">+</span> 0.2
<span class="op">/</span><span class="op">*</span> note velocity <span class="op">*</span><span class="op">/</span>
iamp <span class="op">=</span> 0.0039 <span class="op">+</span> p5 <span class="op">*</span> p5 <span class="op">/</span> 16192
<span class="op">/</span><span class="op">*</span> <span class="opc">vibrato</span> <span class="op">*</span><span class="op">/</span>
kcps <span class="opc">oscili</span> 1, 8, 3
kenv <span class="opc">linseg</span> 0, 0.05, 0, 0.1, 1, 1, 1
<span class="op">/</span><span class="op">*</span> frequency <span class="op">*</span><span class="op">/</span>
kcps <span class="op">=</span> (kcps <span class="op">*</span> kenv <span class="op">*</span> 0.01 <span class="op">+</span> 1) <span class="op">*</span> 440 <span class="op">*</span> <span class="opc">exp</span>(<span class="opc">log</span>(2) <span class="op">*</span> (p4 <span class="op">-</span> 69) <span class="op">/</span> 12)
<span class="op">/</span><span class="op">*</span> <span class="opc">grain</span> ftable <span class="op">*</span><span class="op">/</span>
kfn <span class="op">=</span> <span class="opc">int</span>(256 <span class="op">+</span> 69 <span class="op">+</span> 0.5 <span class="op">+</span> 12 <span class="op">*</span> <span class="opc">log</span>(kcps <span class="op">/</span> 440) <span class="op">/</span> <span class="opc">log</span>(2))
<span class="op">/</span><span class="op">*</span> <span class="opc">grain</span> duration <span class="op">*</span><span class="op">/</span>
kgdur <span class="opc">port</span> 100, 0.1, 20
kgdur <span class="op">=</span> kgdur <span class="op">/</span> kcps
a1 <span class="opc">grain2</span> kcps, kcps <span class="op">*</span> 0.02, kgdur, 50, kfn, 2, <span class="op">-</span>0.5, 22, 2
a1 <span class="opc">butterlp</span> a1, 3000
a2 <span class="opc">grain2</span> kcps, kcps <span class="op">*</span> 0.02, 4 <span class="op">/</span> kcps, 50, kfn, 2, <span class="op">-</span>0.5, 23, 2
a2 <span class="opc">butterbp</span> a2, 12000, 8000
a2 <span class="opc">butterbp</span> a2, 12000, 8000
aenv1 <span class="opc">linseg</span> 0, 0.01, 1, 1, 1
aenv2 <span class="opc">linseg</span> 3, 0.05, 1, 1, 1
aenv3 <span class="opc">linseg</span> 1, p3 <span class="op">-</span> 0.2, 1, 0.07, 0, 1, 0
a1 <span class="op">=</span> aenv1 <span class="op">*</span> aenv3 <span class="op">*</span> (a1 <span class="op">+</span> a2 <span class="op">*</span> 0.7 <span class="op">*</span> aenv2)
ga01 <span class="op">=</span> ga01 <span class="op">+</span> a1 <span class="op">*</span> 10000 <span class="op">*</span> iamp
<span class="oblock">endin</span>
<span class="op">/</span><span class="op">*</span> output <span class="oblock">instr</span> <span class="op">*</span><span class="op">/</span>
<span class="oblock">instr</span> 81
i1 <span class="op">=</span> 0.000001
aLl, aLh, aRl, aRh <span class="opc">spat3di</span> ga01 <span class="op">+</span> i1<span class="op">*</span>i1<span class="op">*</span>i1<span class="op">*</span>i1, 3.0, 4.0, 0.0, 0.5, 7, 4
ga01 <span class="op">=</span> 0
aLl <span class="opc">butterlp</span> aLl, 800.0
aRl <span class="opc">butterlp</span> aRl, 800.0
<span class="opc">outs</span> aLl <span class="op">+</span> aLh, aRl <span class="op">+</span> aRh
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="stamnt">t</span> 0 60
<span class="stamnt">i</span> 1 0.0 1.3 60 127
<span class="stamnt">i</span> 1 2.0 1.3 67 127
<span class="stamnt">i</span> 1 4.0 1.3 64 112
<span class="stamnt">i</span> 1 4.0 1.3 72 112
<span class="stamnt">i</span> 81 0 6.4
<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="See Also">
<a id="idp25549824"></a>
<h2>See Also</h2>
<p>
<a class="link" href="grain3.html" title="grain3"><em class="citetitle">grain3</em></a>
</p>
</div>
<div class="refsect1" title="Credits">
<a id="idp25550872"></a>
<h2>Credits</h2>
<p>
</p>
<table border="0" summary="Simple list" class="simplelist">
<tr>
<td>Author: Istvan Varga</td>
</tr>
</table>
<p>
</p>
<p>New in version 4.15</p>
<p>Updated April 2002 by Istvan Varga</p>
</div>
</div>
<div class="navfooter">
<hr />
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left"><a accesskey="p" href="grain.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="grain3.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">grain </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> grain3</td>
</tr>
</table>
</div>
</body>
</html>
distrib
>
Mageia
>
5
>
x86_64
>
media
>
core-release
>
by-pkgid
>
b707d9a4ee443103660a75ccb6e51334
>
files
>
1777
