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<refentry id="chnget">
<indexterm id="Indexchnget"><primary>chnget</primary></indexterm>
<refentryinfo><title>Signal I/O:Software Bus</title></refentryinfo>
<refmeta>
<refentrytitle>chnget</refentrytitle>
</refmeta>
<refnamediv>
<refname>chnget</refname>
<refpurpose>
Reads data from the software bus.
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<para>
Reads data from a channel of the inward named software bus.
Implies declaring the channel with <emphasis>imode</emphasis>=1 (see also
<link linkend="chn"><citetitle>chn_k, chn_a, and chn_S</citetitle></link>).
</para>
</refsect1>
<refsect1>
<title>Syntax</title>
<synopsis>ival <command>chnget</command> Sname</synopsis>
<synopsis>kval <command>chnget</command> Sname</synopsis>
<synopsis>aval <command>chnget</command> Sname</synopsis>
<synopsis>Sval <command>chnget</command> Sname</synopsis>
</refsect1>
<refsect1>
<title>Initialization</title>
<para>
<emphasis>Sname</emphasis> -- a string that identifies a channel
of the named software bus to read.
</para>
<para>
<emphasis>ival</emphasis> -- the control value read at i-time.
</para>
<para>
<emphasis>Sval</emphasis> -- the string value read at i-time.
</para>
</refsect1>
<refsect1>
<title>Performance</title>
<para>
<emphasis>kval</emphasis> -- the control value read at performance time.
</para>
<para>
<emphasis>aval</emphasis> -- the audio signal read at performance time.
</para>
</refsect1>
<refsect1>
<title>Example</title>
<para>
The example shows the software bus being used as an asynchronous
control signal to select a filter cutoff. It assumes that an
external program that has access to the API is feeding the values.
</para>
<informalexample>
<programlisting>
<emphasis role="ohdr">sr</emphasis> <emphasis role="op">=</emphasis> 44100
<emphasis role="ohdr">kr</emphasis> <emphasis role="op">=</emphasis> 100
<emphasis role="ohdr">ksmps</emphasis> <emphasis role="op">=</emphasis> 1
<emphasis role="oblock">instr</emphasis> 1
kc <emphasis role="opc">chnget</emphasis> "cutoff"
a1 <emphasis role="opc">oscil</emphasis> p4, p5, 100
a2 <emphasis role="opc">lowpass2</emphasis> a1, kc, 200
<emphasis role="opc">out</emphasis> a2
<emphasis role="oblock">endin</emphasis>
</programlisting>
</informalexample>
<para>
Here is another example of the chnget opcode. It uses the file <ulink url="examples/chnget.csd"><citetitle>chnget.csd</citetitle></ulink>.
<example>
<title>Example of the chnget opcode.</title>
<xi:include href="examples-xml/chnget.csd.xml" xmlns:xi="http://www.w3.org/2001/XInclude"/>
</example>
</para>
</refsect1>
<refsect1>
<title>Credits</title>
<para>
<simplelist>
<member>Author: &nameistvan;</member>
<member>2005</member>
</simplelist>
</para>
</refsect1>
</refentry>
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