<?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>pvsfread</title>
<link rel="stylesheet" href="csound.css" type="text/css" />
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2" />
<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="pvsfilter.html" title="pvsfilter" />
<link rel="next" href="pvsfreeze.html" title="pvsfreeze" />
</head>
<body>
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr>
<th colspan="3" align="center">pvsfread</th>
</tr>
<tr>
<td width="20%" align="left"><a accesskey="p" href="pvsfilter.html">Prev</a> </td>
<th width="60%" align="center">Orchestra Opcodes and Operators</th>
<td width="20%" align="right"> <a accesskey="n" href="pvsfreeze.html">Next</a></td>
</tr>
</table>
<hr />
</div>
<div class="refentry" title="pvsfread">
<a id="pvsfread"></a>
<div class="titlepage"></div>
<a id="IndexPvsfread" class="indexterm"></a>
<div class="refnamediv">
<h2>
<span class="refentrytitle">pvsfread</span>
</h2>
<p>pvsfread —
Read a selected channel from a PVOC-EX analysis file.
</p>
</div>
<div class="refsect1" title="Description">
<a id="id3133929"></a>
<h2>Description</h2>
<p>
Create an fsig stream by reading a selected channel from a PVOC-EX analysis file loaded into memory, with frame interpolation. Only format 0 files (amplitude+frequency) are currently supported. The operation of this opcode mirrors that of pvoc, but outputs an fsig instead of a resynthesized signal.
</p>
</div>
<div class="refsect1" title="Syntax">
<a id="id3134858"></a>
<h2>Syntax</h2>
<pre class="synopsis">fsig <span class="command"><strong>pvsfread</strong></span> ktimpt, ifn [, ichan]</pre>
</div>
<div class="refsect1" title="Initialization">
<a id="id3134874"></a>
<h2>Initialization</h2>
<p>
<span class="emphasis"><em>ifn</em></span> -- Name of the analysis file. This must have the .pvx file extension.
</p>
<p>
A multi-channel PVOC-EX file can be generated using the extended <a class="link" href="pvanal.html" title="pvanal"><em class="citetitle">pvanal utility</em></a>.
</p>
<p>
<span class="emphasis"><em>ichan</em></span> -- (optional) The channel to read (counting from 0). Default is 0.
</p>
</div>
<div class="refsect1" title="Performance">
<a id="id3134909"></a>
<h2>Performance</h2>
<p>
<span class="emphasis"><em>ktimpt</em></span> -- Time pointer into analysis file, in seconds. See the description of the same parameter of <a class="link" href="pvoc.html" title="pvoc"><em class="citetitle">pvoc</em></a> for usage.
</p>
<p>
Note that analysis files can be very large, especially if multi-channel. Reading such files into memory will very likely incur breaks in the audio during real-time performance. As the file is read only once, and is then available to all other interested opcodes, it can be expedient to arrange for a dedicated instrument to preload all such analysis files at startup.
</p>
</div>
<div class="refsect1" title="Examples">
<a id="id3134942"></a>
<h2>Examples</h2>
<p>
</p>
<div class="informalexample">
<pre class="programlisting">
idur filelen "test.pvx" ; find dur of (stereo) analysis file
kpos line 0,p3,idur ; to ensure we process whole file
fsigr pvsfread kpos,"test.pvx",1 ; create fsig from R channel
</pre>
</div>
<p>
(NB: as this example shows, the filelen opcode has been extended to accept both old and new analysis file formats).
</p>
</div>
<div class="refsect1" title="Credits">
<a id="id3134969"></a>
<h2>Credits</h2>
<p>
</p>
<table border="0" summary="Simple list" class="simplelist">
<tr>
<td>Author: Richard Dobson</td>
</tr>
<tr>
<td>August 2001 </td>
</tr>
</table>
<p>
</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="pvsfilter.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="pvsfreeze.html">Next</a></td>
</tr>
<tr>
<td width="40%" align="left" valign="top">pvsfilter </td>
<td width="20%" align="center">
<a accesskey="h" href="index.html">Home</a>
</td>
<td width="40%" align="right" valign="top"> pvsfreeze</td>
</tr>
</table>
</div>
</body>
</html>
