File: 04-ping-pong-delay.html

package info (click to toggle)
python-pyo 1.0.6-2
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 52,332 kB
  • sloc: python: 135,133; ansic: 127,822; javascript: 16,116; sh: 395; makefile: 388; cpp: 242
file content (180 lines) | stat: -rw-r--r-- 16,385 bytes parent folder | download | duplicates (2) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
 

<!DOCTYPE html>

<html lang="en">
<head>
<meta charset="utf-8"/>
<meta content="width=device-width, initial-scale=1.0" name="viewport"/><meta content="Docutils 0.17.1: http://docutils.sourceforge.net/" name="generator"/>
<title>04-ping-pong-delay.py - Stereo ping-pong delay. — Pyo 1.0.5 documentation</title>
<link href="../../_static/pygments.css" rel="stylesheet" type="text/css"/>
<link href="../../_static/agogo.css" rel="stylesheet" type="text/css"/>
<link href="../../_static/sphinx-codeautolink.css" rel="stylesheet" type="text/css"/>
<link href="../../_static/autoclasstoc.css" rel="stylesheet" type="text/css"/>
<script data-url_root="../../" id="documentation_options" src="../../_static/documentation_options.js"></script>
<script src="../../_static/jquery.js"></script>
<script src="../../_static/underscore.js"></script>
<script src="../../_static/_sphinx_javascript_frameworks_compat.js"></script>
<script src="../../_static/doctools.js"></script>
<script src="../../_static/sphinx_highlight.js"></script>
<link href="../../_static/E-PyoIcon.ico" rel="shortcut icon"/>
<link href="../../about.html" rel="author" title="About these documents"/>
<link href="../../genindex.html" rel="index" title="Index"/>
<link href="../../search.html" rel="search" title="Search"/>
<link href="05-hand-made-chorus.html" rel="next" title="06-hand-made-chorus.py - Hand-written 8 delay lines stereo chorus."/>
<link href="03-fuzz-disto.html" rel="prev" title="03-fuzz-disto.py - Hand-written asymmetrical tranfert function."/>
</head><body>
<div class="header-wrapper" role="banner">
<div class="header">
<div class="headertitle"><a href="../../index.html">Pyo 1.0.5 documentation</a></div>
<div aria-label="related navigation" class="rel" role="navigation">
<a accesskey="P" href="03-fuzz-disto.html" title="03-fuzz-disto.py - Hand-written asymmetrical tranfert function.">previous</a> |
          <a accesskey="N" href="05-hand-made-chorus.html" title="06-hand-made-chorus.py - Hand-written 8 delay lines stereo chorus.">next</a> |
          <a accesskey="I" href="../../genindex.html" title="General Index">index</a>
</div>
</div>
</div>
<div class="content-wrapper">
<div class="content">
<div class="sidebar">
<h3>Table of Contents</h3>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../../about.html">About pyo</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../download.html">Installing pyo with pip</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../compiling.html">Compiling pyo from sources</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../structure.html">Structure of the library</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../gettingstarted.html">Getting started</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../winaudioinspect.html">Configuring the audio output (Windows)</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../perftips.html">Improve performance of pyo programs</a></li>
</ul>
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="../../api/index.html">API documentation</a></li>
<li class="toctree-l1 current"><a class="reference internal" href="../index.html">Examples</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="../01-intro/index.html">First steps</a></li>
<li class="toctree-l2"><a class="reference internal" href="../02-controls/index.html">Parameter control</a></li>
<li class="toctree-l2"><a class="reference internal" href="../03-generators/index.html">Synthesis generators</a></li>
<li class="toctree-l2"><a class="reference internal" href="../04-soundfiles/index.html">Playing with soundfiles</a></li>
<li class="toctree-l2"><a class="reference internal" href="../05-envelopes/index.html">Amplitude envelopes</a></li>
<li class="toctree-l2"><a class="reference internal" href="../06-filters/index.html">Filtering</a></li>
<li class="toctree-l2 current"><a class="reference internal" href="index.html">Creating sound effects</a></li>
<li class="toctree-l2"><a class="reference internal" href="../08-dynamics/index.html">Dynamic range of audio signals</a></li>
<li class="toctree-l2"><a class="reference internal" href="../09-callbacks/index.html">Calling python functions from audio objects</a></li>
<li class="toctree-l2"><a class="reference internal" href="../10-tables/index.html">Using tables</a></li>
<li class="toctree-l2"><a class="reference internal" href="../16-midi/index.html">How to use MIDI with pyo</a></li>
<li class="toctree-l2"><a class="reference internal" href="../17-osc/index.html">How to use OSC with pyo</a></li>
<li class="toctree-l2"><a class="reference internal" href="../19-multirate/index.html">Multirate audio processing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../20-multicore/index.html">Multicore audio programming</a></li>
<li class="toctree-l2"><a class="reference internal" href="../21-utilities/index.html">Utilities</a></li>
<li class="toctree-l2"><a class="reference internal" href="../22-events/index.html">Events framework</a></li>
<li class="toctree-l2"><a class="reference internal" href="../23-expression/index.html">Evaluating prefix expression</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../../tutorials/index.html">Advanced tutorials</a></li>
</ul>
<div role="search">
<h3 style="margin-top: 1.5em;">Search</h3>
<form action="../../search.html" class="search" method="get">
<input name="q" type="text"/>
<input type="submit" value="Go"/>
</form>
</div>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<section id="ping-pong-delay-py-stereo-ping-pong-delay">
<h1>04-ping-pong-delay.py - Stereo ping-pong delay.<a class="headerlink" href="#ping-pong-delay-py-stereo-ping-pong-delay" title="Permalink to this heading">¶</a></h1>
<p>A stereo ping-pong delay is when you use two delays, one hard left and the
other hard right, and the delays alternate.</p>
<p>This exemple illustrates how we can pass the signal of a first object to
the input of a second even if the first object does not exist yet when the
second is created.</p>
<div class="highlight-python notranslate"><div class="highlight"><pre><span></span><span class="kn">from</span> <a class="sphinx-codeautolink-a" href="../../api/alphabetical.html#module-pyo" title="pyo"><span class="nn">pyo</span></a> <span class="kn">import</span> <span class="o">*</span>
<span class="kn">import</span> <span class="nn">random</span>

<span class="n">s</span> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/server.html#pyo.Server" title="pyo.lib.server.Server"><span class="n">Server</span></a><span class="p">(</span><span class="n">duplex</span><span class="o">=</span><span class="mi">0</span><span class="p">)</span><span class="o">.</span><span class="n">boot</span><span class="p">()</span>

<span class="c1"># Compute the duration, in seconds, of one buffer size.</span>
<span class="n">buftime</span> <span class="o">=</span> <span class="n">s</span><span class="o">.</span><span class="n">getBufferSize</span><span class="p">()</span> <span class="o">/</span> <span class="n">s</span><span class="o">.</span><span class="n">getSamplingRate</span><span class="p">()</span>

<span class="c1"># Delay parameters</span>
<a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_time_l</span></a> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">Sig</span></a><span class="p">(</span><span class="mf">0.125</span><span class="p">)</span>  <span class="c1"># Delay time for the left channel delay.</span>
<span class="n">delay_time_l</span><span class="o">.</span><span class="n">ctrl</span><span class="p">()</span>
<a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_feed</span></a> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">Sig</span></a><span class="p">(</span><span class="mf">0.75</span><span class="p">)</span>  <span class="c1"># Feedback value for both delays.</span>
<span class="n">delay_feed</span><span class="o">.</span><span class="n">ctrl</span><span class="p">()</span>

<span class="c1"># Because the right delay gets its input sound from the left delay, while</span>
<span class="c1"># it is computed before (to send its output sound to the left delay), it</span>
<span class="c1"># will be one buffer size late. To compensate this additional delay on the</span>
<span class="c1"># right, we substract one buffer size from the real delay time.</span>
<a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_time_r</span></a> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">Sig</span></a><span class="p">(</span><a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_time_l</span></a><span class="p">,</span> <span class="n">add</span><span class="o">=-</span><span class="n">buftime</span><span class="p">)</span>

<span class="c1"># Setup up a soundfile player.</span>
<span class="n">sf</span> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/players.html#pyo.SfPlayer" title="pyo.lib.players.SfPlayer"><span class="n">SfPlayer</span></a><span class="p">(</span><span class="s2">"../snds/alum1.wav"</span><span class="p">)</span><span class="o">.</span><span class="n">stop</span><span class="p">()</span>

<span class="c1"># Send the original sound to both speakers.</span>
<span class="n">sfout</span> <span class="o">=</span> <span class="n">sf</span><span class="o">.</span><span class="n">mix</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span><span class="o">.</span><span class="n">out</span><span class="p">()</span>

<span class="c1"># Initialize the right delay with zeros as input because the left delay</span>
<span class="c1"># does not exist yet.</span>
<span class="n">right</span> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/effects.html#pyo.Delay" title="pyo.lib.effects.Delay"><span class="n">Delay</span></a><span class="p">(</span><a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">Sig</span></a><span class="p">(</span><span class="mi">0</span><span class="p">),</span> <span class="n">delay</span><span class="o">=</span><a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_time_r</span></a><span class="p">)</span><span class="o">.</span><span class="n">out</span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>

<span class="c1"># Initialize the left delay with the original mono source and the right</span>
<span class="c1"># delay signal (multiplied by the feedback value) as input.</span>
<span class="n">left</span> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/effects.html#pyo.Delay" title="pyo.lib.effects.Delay"><span class="n">Delay</span></a><span class="p">(</span><span class="n">sf</span> <span class="o">+</span> <span class="n">right</span> <span class="o">*</span> <a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_feed</span></a><span class="p">,</span> <span class="n">delay</span><span class="o">=</span><a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_time_l</span></a><span class="p">)</span><span class="o">.</span><span class="n">out</span><span class="p">()</span>

<span class="c1"># One issue with recursive cross-delay is if we set the feedback to</span>
<span class="c1"># 0, the right delay never gets any signal. To resolve this, we add a</span>
<span class="c1"># non-recursive delay, with a gain that is the inverse of the feedback,</span>
<span class="c1"># to the right delay input.</span>
<a class="sphinx-codeautolink-a" href="../../api/classes/effects.html#pyo.Delay" title="pyo.lib.effects.Delay"><span class="n">original_delayed</span></a> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/effects.html#pyo.Delay" title="pyo.lib.effects.Delay"><span class="n">Delay</span></a><span class="p">(</span><span class="n">sf</span><span class="p">,</span> <a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_time_l</span></a><span class="p">,</span> <span class="n">mul</span><span class="o">=</span><span class="mi">1</span> <span class="o">-</span> <a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_feed</span></a><span class="p">)</span>

<span class="c1"># Change the right delay input (now that the left delay exists).</span>
<span class="n">right</span><span class="o">.</span><span class="n">setInput</span><span class="p">(</span><a class="sphinx-codeautolink-a" href="../../api/classes/effects.html#pyo.Delay" title="pyo.lib.effects.Delay"><span class="n">original_delayed</span></a> <span class="o">+</span> <span class="n">left</span> <span class="o">*</span> <a class="sphinx-codeautolink-a" href="../../api/classes/controls.html#pyo.Sig" title="pyo.lib._core.Sig"><span class="n">delay_feed</span></a><span class="p">)</span>


<span class="k">def</span> <span class="nf">playit</span><span class="p">():</span>
    <span class="s2">"Assign a sound to the player and start playback."</span>
    <span class="n">which</span> <span class="o">=</span> <span class="n">random</span><span class="o">.</span><span class="n">randint</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="mi">4</span><span class="p">)</span>
    <span class="n">path</span> <span class="o">=</span> <span class="s2">"../snds/alum</span><span class="si">%d</span><span class="s2">.wav"</span> <span class="o">%</span> <span class="n">which</span>
    <span class="n">sf</span><span class="o">.</span><span class="n">path</span> <span class="o">=</span> <span class="n">path</span>
    <span class="n">sf</span><span class="o">.</span><span class="n">play</span><span class="p">()</span>


<span class="c1"># Call the function "playit" every second.</span>
<span class="n">pat</span> <span class="o">=</span> <a class="sphinx-codeautolink-a" href="../../api/classes/pattern.html#pyo.Pattern" title="pyo.lib.pattern.Pattern"><span class="n">Pattern</span></a><span class="p">(</span><span class="n">playit</span><span class="p">,</span> <span class="mi">1</span><span class="p">)</span><span class="o">.</span><span class="n">play</span><span class="p">()</span>

<span class="n">s</span><span class="o">.</span><span class="n">gui</span><span class="p">(</span><span class="nb">locals</span><span class="p">())</span>
</pre></div>
</div>
</section>
<div class="clearer"></div>
</div>
</div>
</div>
</div>
<div class="clearer"></div>
</div>
</div>
<div class="footer-wrapper">
<div class="footer">
<div class="left">
<div aria-label="related navigaton" role="navigation">
<a href="03-fuzz-disto.html" title="03-fuzz-disto.py - Hand-written asymmetrical tranfert function.">previous</a> |
            <a href="05-hand-made-chorus.html" title="06-hand-made-chorus.py - Hand-written 8 delay lines stereo chorus.">next</a> |
            <a href="../../genindex.html" title="General Index">index</a>
</div>
<div aria-label="source link" role="note">
</div>
</div>
<div class="right">
<div class="footer" role="contentinfo">
        © Copyright 2021, Olivier Bélanger.
      Created using <a href="https://www.sphinx-doc.org/">Sphinx</a> 5.3.0.
    </div>
</div>
<div class="clearer"></div>
</div>
</div>
</body>
</html>