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<h2>
<span class="refentrytitle">pvstanal</span>
</h2>
<p>pvstanal —
Phase vocoder analysis processing with onset detection/processing.
</p>
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<div class="refsect1" title="Description">
<a id="id3142632"></a>
<h2>Description</h2>
<p>
<span class="emphasis"><em>pvstanal</em></span> implements phase vocoder analysis by reading function tables
containing sampled-sound sources, with <a class="link" href="GEN01.html" title="GEN01"><em class="citetitle">GEN01</em></a>, and
<span class="emphasis"><em>pvstanal</em></span> will accept deferred allocation tables.
</p>
<p>
This opcode allows for time and frequency-independent scaling. Time is advanced internally, but controlled by a tempo scaling parameter; when an onset is detected, timescaling is momentarily stopped to avoid smearing of attacks. The quality of the effect is generally improved with phase locking switched on.
</p>
<p>
<span class="emphasis"><em>pvstanal</em></span> will also scale pitch, independently of frequency, using a transposition factor (k-rate).
</p>
</div>
<div class="refsect1" title="Syntax">
<a id="id3143617"></a>
<h2>Syntax</h2>
<pre class="synopsis">asig <span class="command"><strong>pvstanal</strong></span> ktimescal,kamp,kpitch,ktab,[kdetect, kwrap, ioffset,ifftsize, ihop, ithresh]
</pre>
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<div class="refsect1" title="Initialization">
<a id="id3143639"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>ifftsize</em></span> -- FFT size (power-of-two), defaults to 2048.
</p>
<p>
<span class="emphasis"><em>ihop</em></span> -- hopsize, defaults to 512
</p>
<p>
<span class="emphasis"><em>ioffset</em></span> -- startup read offset into table, in secs.
</p>
<p>
<span class="emphasis"><em>idbthresh</em></span> -- threshold based on dB power spectrum ratio between two successive windows. A detected ratio above it will cancel timescaling momentarily, to avoid smearing (defaults to 1)
</p>
</div>
<div class="refsect1" title="Performance">
<a id="id3143684"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>ktimescal</em></span> -- timescaling ratio, < 1 stretch, > 1 contract.
</p>
<p>
<span class="emphasis"><em>kamp</em></span> -- amplitude scaling
</p>
<p>
<span class="emphasis"><em>kpitch</em></span> -- grain pitch scaling (1=normal pitch, < 1 lower, > 1 higher; negative, backwards)
</p>
<p>
<span class="emphasis"><em>kdetect</em></span> -- 0 or 1, to switch onset detection/processing
</p>
<p>
<span class="emphasis"><em>ktab</em></span> -- source signal function table. Deferred-allocation tables (see
<a class="link" href="GEN01.html" title="GEN01"><em class="citetitle">GEN01</em></a>) are accepted, but the opcode
expects a mono source. Tables can be switched at k-rate.
</p>
<p>
<span class="emphasis"><em>kwrap</em></span> -- 0 or 1, to switch on/off table wrap-around read (default to 1)
</p>
</div>
<div class="refsect1" title="Examples">
<a id="id3143756"></a>
<h2>Examples</h2>
<p>
</p>
<div class="example">
<a id="id3143763"></a>
<p class="title">
<b>Example 495. Example</b>
</p>
<div class="example-contents">
<pre class="programlisting">
idur = p3
ilock = p4
itab = 1
ipitch = 1
iamp = 0.8
ktime linseg 0.3, p3/2, 0.8, p3/2, 0.3
fs1 pvstanal ktime,iamp,ipitch,itab
a1 pvsynth fs1
out a1
</pre>
</div>
</div>
<p><br class="example-break" />
</p>
</div>
<div class="refsect1" title="Credits">
<a id="id3143782"></a>
<h2>Credits</h2>
<p>
</p>
<table border="0" summary="Simple list" class="simplelist">
<tr>
<td>Author: Victor Lazzarini</td>
</tr>
<tr>
<td>February 2010</td>
</tr>
</table>
<p>
</p>
<p>New plugin in version 5.13</p>
<p>February 2005.</p>
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