You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
145 lines
4.7 KiB
145 lines
4.7 KiB
<!DOCTYPE html>
|
|
|
|
<!--Converted with LaTeX2HTML 2002-2-1 (1.71)
|
|
original version by: Nikos Drakos, CBLU, University of Leeds
|
|
* revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan
|
|
* with significant contributions from:
|
|
Jens Lippmann, Marek Rouchal, Martin Wilck and others -->
|
|
<HTML>
|
|
<HEAD>
|
|
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
|
|
|
|
<TITLE>Analog-style sequencer</TITLE>
|
|
<META NAME="description" CONTENT="Analog-style sequencer">
|
|
<META NAME="keywords" CONTENT="book">
|
|
<META NAME="resource-type" CONTENT="document">
|
|
<META NAME="distribution" CONTENT="global">
|
|
|
|
<META NAME="Generator" CONTENT="LaTeX2HTML v2002-2-1">
|
|
<META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css">
|
|
|
|
<LINK REL="STYLESHEET" HREF="book.css">
|
|
|
|
<LINK REL="next" HREF="node56.html">
|
|
<LINK REL="previous" HREF="node54.html">
|
|
<LINK REL="up" HREF="node50.html">
|
|
<LINK REL="next" HREF="node56.html">
|
|
</HEAD>
|
|
|
|
<BODY >
|
|
<!--Navigation Panel-->
|
|
<A ID="tex2html1363"
|
|
HREF="node56.html">
|
|
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next"
|
|
SRC="next.png"></A>
|
|
<A ID="tex2html1357"
|
|
HREF="node50.html">
|
|
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up"
|
|
SRC="up.png"></A>
|
|
<A ID="tex2html1351"
|
|
HREF="node54.html">
|
|
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous"
|
|
SRC="prev.png"></A>
|
|
<A ID="tex2html1359"
|
|
HREF="node4.html">
|
|
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents"
|
|
SRC="contents.png"></A>
|
|
<A ID="tex2html1361"
|
|
HREF="node201.html">
|
|
<IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index"
|
|
SRC="index.png"></A>
|
|
<BR>
|
|
<B> Next:</B> <A ID="tex2html1364"
|
|
HREF="node56.html">MIDI-style synthesizer</A>
|
|
<B> Up:</B> <A ID="tex2html1358"
|
|
HREF="node50.html">Examples</A>
|
|
<B> Previous:</B> <A ID="tex2html1352"
|
|
HREF="node54.html">Signals to controls</A>
|
|
<B> <A ID="tex2html1360"
|
|
HREF="node4.html">Contents</A></B>
|
|
<B> <A ID="tex2html1362"
|
|
HREF="node201.html">Index</A></B>
|
|
<BR>
|
|
<BR>
|
|
<!--End of Navigation Panel-->
|
|
|
|
<H2><A ID="SECTION007105000000000000000">
|
|
Analog-style sequencer</A>
|
|
</H2>
|
|
|
|
<P>
|
|
Example C08.analog.sequencer.pd (Figure <A HREF="#fig03.15">3.15</A>) realizes the analog sequencer and envelope
|
|
generation described in Section <A HREF="node47.html#sect3.analog">3.7</A>. The "sequence" table,
|
|
with nine elements, holds a sequence of frequencies. The <TT>phasor~</TT> object at top cycles through the sequence table at 0.6 Hertz. Non-interpolating
|
|
table lookup (<TT>tabread~</TT> instead of <TT>tabread4~</TT>) is
|
|
used to read the frequencies in discrete steps. (Such situations, in
|
|
which we prefer non-interpolating table lookup, are rare.)
|
|
|
|
<P>
|
|
|
|
<DIV ALIGN="CENTER"><A ID="fig03.15"></A><A ID="3777"></A>
|
|
<TABLE>
|
|
<CAPTION ALIGN="BOTTOM"><STRONG>Figure 3.15:</STRONG>
|
|
An analog-synthesizer-style sequencer.</CAPTION>
|
|
<TR><TD><IMG
|
|
WIDTH="463" HEIGHT="692" BORDER="0"
|
|
SRC="img350.png"
|
|
ALT="\begin{figure}\psfig{file=figs/fig03.15.ps}\end{figure}"></TD></TR>
|
|
</TABLE>
|
|
</DIV>
|
|
|
|
<P>
|
|
The <TT>wrap~</TT> object converts the amplitude-9 sawtooth to a unit-amplitude
|
|
one as described earlier in Figure <A HREF="node47.html#fig03.08">3.8</A>, which is then used to obtain
|
|
an envelope function from a second wavetable. This is used to control grain
|
|
size in a looping sampler (from Section <A HREF="node36.html#sect2.example.loop">2.6</A>). Here the
|
|
wavetable consists of six periods of a sinusoid. The grains are smoothed by
|
|
multiplying by a raised cosine function (<TT>cos~</TT> and <TT>+ 1</TT>).
|
|
|
|
<P>
|
|
Example C09.sample.hold.pd (not pictured here) shows a sample-and-hold unit, another
|
|
useful device for doing control tasks in the audio signal domain.
|
|
|
|
<P>
|
|
<HR>
|
|
<!--Navigation Panel-->
|
|
<A ID="tex2html1363"
|
|
HREF="node56.html">
|
|
<IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next"
|
|
SRC="next.png"></A>
|
|
<A ID="tex2html1357"
|
|
HREF="node50.html">
|
|
<IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up"
|
|
SRC="up.png"></A>
|
|
<A ID="tex2html1351"
|
|
HREF="node54.html">
|
|
<IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous"
|
|
SRC="prev.png"></A>
|
|
<A ID="tex2html1359"
|
|
HREF="node4.html">
|
|
<IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents"
|
|
SRC="contents.png"></A>
|
|
<A ID="tex2html1361"
|
|
HREF="node201.html">
|
|
<IMG WIDTH="43" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="index"
|
|
SRC="index.png"></A>
|
|
<BR>
|
|
<B> Next:</B> <A ID="tex2html1364"
|
|
HREF="node56.html">MIDI-style synthesizer</A>
|
|
<B> Up:</B> <A ID="tex2html1358"
|
|
HREF="node50.html">Examples</A>
|
|
<B> Previous:</B> <A ID="tex2html1352"
|
|
HREF="node54.html">Signals to controls</A>
|
|
<B> <A ID="tex2html1360"
|
|
HREF="node4.html">Contents</A></B>
|
|
<B> <A ID="tex2html1362"
|
|
HREF="node201.html">Index</A></B>
|
|
<!--End of Navigation Panel-->
|
|
<ADDRESS>
|
|
Miller Puckette
|
|
2006-12-30
|
|
</ADDRESS>
|
|
</BODY>
|
|
</HTML>
|
|
|