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<div class="refentry" title="filepeak">
<a id="filepeak"></a>
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<a id="IndexFilepeak" class="indexterm"></a>
<div class="refnamediv">
<h2>
<span class="refentrytitle">filepeak</span>
</h2>
<p>filepeak —
Returns the peak absolute value of a sound file.
</p>
</div>
<div class="refsect1" title="Description">
<a id="idp20020440"></a>
<h2>Description</h2>
<p>
Returns the peak absolute value of a sound file.
</p>
</div>
<div class="refsect1" title="Syntax">
<a id="idp20021176"></a>
<h2>Syntax</h2>
<pre class="synopsis">ir <span class="command"><strong>filepeak</strong></span> ifilcod [, ichnl]</pre>
</div>
<div class="refsect1" title="Initialization">
<a id="idp20031496"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>ifilcod</em></span> -- sound file to be queried
</p>
<p>
<span class="emphasis"><em>ichnl</em></span> (optional, default=0) -- channel to be used in calculating the peak value. Default is 0.
</p>
<div class="itemizedlist">
<ul class="itemizedlist" type="disc">
<li class="listitem">
<p><span class="emphasis"><em>ichnl</em></span> = 0 returns peak value of all channels</p>
</li>
<li class="listitem">
<p><span class="emphasis"><em>ichnl</em></span> > 0 returns peak value of <span class="emphasis"><em>ichnl</em></span></p>
</li>
</ul>
</div>
<p>
</p>
</div>
<div class="refsect1" title="Performance">
<a id="idp20034488"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>filepeak</em></span> returns the peak absolute value of the sound file <span class="emphasis"><em>ifilcod</em></span>.
</p>
</div>
<div class="refsect1" title="Examples">
<a id="idp20107984"></a>
<h2>Examples</h2>
<p>
Here is an example of the filepeak opcode. It uses the file <a class="ulink" href="examples/filepeak.csd" target="_top"><em class="citetitle">filepeak.csd</em></a>,
and <a class="ulink" href="examples/Church.wav" target="_top"><em class="citetitle">Church.wav</em></a>.
</p>
<div class="example">
<a id="idp20109352"></a>
<p class="title">
<strong>Example 228. Example of the filepeak 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>
-odac <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc ;;;uncomment -iadc if realtime audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o filepeak.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> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span> <span class="op">=</span> 1
<span class="oblock">instr</span> 1
iscaldb <span class="op">=</span> p4 <span class="comment">;set peak amplitude in dB</span>
ipeak <span class="opc">filepeak</span> "Church.wav"
iscal <span class="op">=</span> <span class="opc">ampdb</span>(iscaldb)<span class="op">/</span>ipeak <span class="comment">;calculate amp multiplier</span>
<span class="opc">printf_i</span> "\nPeak value <span class="opc">in</span> file '<span class="op">%</span>s' is <span class="op">%</span>f (<span class="op">%</span>.3f dB).\n\n", 1, "Church.wav", ipeak, <span class="opc">dbamp</span>(ipeak)
asnd <span class="opc">soundin</span> "Church.wav"
<span class="opc">outs</span> asnd, asnd
<span class="comment">; scale & write file to disk</span>
asig <span class="op">=</span> asnd<span class="op">*</span>iscal <span class="comment">;scale to p4</span>
<span class="opc">fout</span> "Church_norm.wav", 14, asig
<span class="oblock">endin</span>
<span class="oblock">instr</span> 2 <span class="comment">; play scaled file</span>
aout <span class="opc">soundin</span> "Church_norm.wav"
ipknew <span class="opc">filepeak</span> "Church_norm.wav"
<span class="opc">printf_i</span> "\nPeak value <span class="opc">in</span> file '<span class="op">%</span>s' is <span class="op">%</span>f (<span class="op">%</span>.3f dB).\n\n", 1, "Church_norm.wav", ipknew, <span class="opc">dbamp</span>(ipknew)
<span class="opc">outs</span> aout, aout
<span class="oblock">endin</span>
<span class="csdtag"></CsInstruments></span>
<span class="csdtag"><CsScore></span>
<span class="stamnt">i</span> 1 0 2 -6 <span class="comment">; normalize audio to -6 dB</span>
<span class="stamnt">i</span> 2 2 2
<span class="stamnt">e</span>
<span class="csdtag"></CsScore></span>
<span class="csdtag"></CsoundSynthesizer></span>
</pre>
</div>
</div>
<p><br class="example-break" />
The <span class="emphasis"><em>filepeak</em></span>'s output should include lines like this:
</p>
<pre class="screen">
Peak value in file 'Church.wav' is 0.909363 (-0.825 dB).
Peak value in file 'Church_norm.wav' is 0.501190 (-6.000 dB).
</pre>
<p>
</p>
</div>
<div class="refsect1" title="See Also">
<a id="idp20112544"></a>
<h2>See Also</h2>
<p>
<a class="link" href="filelen.html" title="filelen"><em class="citetitle">filelen</em></a>,
<a class="link" href="filenchnls.html" title="filenchnls"><em class="citetitle">filenchnls</em></a>,
<a class="link" href="filesr.html" title="filesr"><em class="citetitle">filesr</em></a>
</p>
</div>
<div class="refsect1" title="Credits">
<a id="idp20114592"></a>
<h2>Credits</h2>
<p>
</p>
<table border="0" summary="Simple list" class="simplelist">
<tr>
<td>Author: Matt Ingalls</td>
</tr>
<tr>
<td>July 1999</td>
</tr>
</table>
<p>
</p>
<p>New in Csound version 3.57</p>
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distrib
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Mageia
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media
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core-release
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b707d9a4ee443103660a75ccb6e51334
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