<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>tonegenerator.cpp Example File | Qt Multimedia 5.9</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.9</td><td ><a href="qtmultimedia-index.html">Qt Multimedia</a></td><td ><a href="qtmultimedia-multimedia-spectrum-example.html">Spectrum Example</a></td><td >tonegenerator.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"><div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">tonegenerator.cpp Example File</h1> <span class="subtitle">multimedia/spectrum/app/tonegenerator.cpp</span> <!-- $$$multimedia/spectrum/app/tonegenerator.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2017 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include "spectrum.h"</span> <span class="preprocessor">#include "utils.h"</span> <span class="preprocessor">#include <QByteArray></span> <span class="preprocessor">#include <QAudioFormat></span> <span class="preprocessor">#include <qmath.h></span> <span class="preprocessor">#include <qendian.h></span> <span class="type">void</span> generateTone(<span class="keyword">const</span> SweptTone <span class="operator">&</span>tone<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format<span class="operator">,</span> <span class="type">QByteArray</span> <span class="operator">&</span>buffer) { Q_ASSERT(isPCMS16LE(format)); <span class="keyword">const</span> <span class="type">int</span> channelBytes <span class="operator">=</span> format<span class="operator">.</span>sampleSize() <span class="operator">/</span> <span class="number">8</span>; <span class="keyword">const</span> <span class="type">int</span> sampleBytes <span class="operator">=</span> format<span class="operator">.</span>channelCount() <span class="operator">*</span> channelBytes; <span class="type">int</span> length <span class="operator">=</span> buffer<span class="operator">.</span>size(); <span class="keyword">const</span> <span class="type">int</span> numSamples <span class="operator">=</span> buffer<span class="operator">.</span>size() <span class="operator">/</span> sampleBytes; Q_ASSERT(length <span class="operator">%</span> sampleBytes <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>); Q_UNUSED(sampleBytes) <span class="comment">// suppress warning in release builds</span> <span class="type">unsigned</span> <span class="type">char</span> <span class="operator">*</span>ptr <span class="operator">=</span> <span class="keyword">reinterpret_cast</span><span class="operator"><</span><span class="type">unsigned</span> <span class="type">char</span> <span class="operator">*</span><span class="operator">></span>(buffer<span class="operator">.</span>data()); <span class="type">qreal</span> phase <span class="operator">=</span> <span class="number">0.0</span>; <span class="keyword">const</span> <span class="type">qreal</span> d <span class="operator">=</span> <span class="number">2</span> <span class="operator">*</span> M_PI <span class="operator">/</span> format<span class="operator">.</span>sampleRate(); <span class="comment">// We can't generate a zero-frequency sine wave</span> <span class="keyword">const</span> <span class="type">qreal</span> startFreq <span class="operator">=</span> tone<span class="operator">.</span>startFreq <span class="operator">?</span> tone<span class="operator">.</span>startFreq : <span class="number">1.0</span>; <span class="comment">// Amount by which phase increases on each sample</span> <span class="type">qreal</span> phaseStep <span class="operator">=</span> d <span class="operator">*</span> startFreq; <span class="comment">// Amount by which phaseStep increases on each sample</span> <span class="comment">// If this is non-zero, the output is a frequency-swept tone</span> <span class="keyword">const</span> <span class="type">qreal</span> phaseStepStep <span class="operator">=</span> d <span class="operator">*</span> (tone<span class="operator">.</span>endFreq <span class="operator">-</span> startFreq) <span class="operator">/</span> numSamples; <span class="keyword">while</span> (length) { <span class="keyword">const</span> <span class="type">qreal</span> x <span class="operator">=</span> tone<span class="operator">.</span>amplitude <span class="operator">*</span> qSin(phase); <span class="keyword">const</span> <span class="type">qint16</span> value <span class="operator">=</span> realToPcm(x); <span class="keyword">for</span> (<span class="type">int</span> i<span class="operator">=</span><span class="number">0</span>; i<span class="operator"><</span>format<span class="operator">.</span>channelCount(); <span class="operator">+</span><span class="operator">+</span>i) { qToLittleEndian<span class="operator"><</span><span class="type">qint16</span><span class="operator">></span>(value<span class="operator">,</span> ptr); ptr <span class="operator">+</span><span class="operator">=</span> channelBytes; length <span class="operator">-</span><span class="operator">=</span> channelBytes; } phase <span class="operator">+</span><span class="operator">=</span> phaseStep; <span class="keyword">while</span> (phase <span class="operator">></span> <span class="number">2</span> <span class="operator">*</span> M_PI) phase <span class="operator">-</span><span class="operator">=</span> <span class="number">2</span> <span class="operator">*</span> M_PI; phaseStep <span class="operator">+</span><span class="operator">=</span> phaseStepStep; } } </pre> </div> <!-- @@@multimedia/spectrum/app/tonegenerator.cpp --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2017 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>