<?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>spectrumanalyser.h Example File | Qt Multimedia 5.12.2</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 5.12</td><td ><a href="qtmultimedia-index.html">Qt Multimedia</a></td><td ><a href="qtmultimedia-multimedia-spectrum-example.html">Spectrum Example</a></td><td >spectrumanalyser.h Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtmultimedia-index.html">Qt 5.12.2 Reference Documentation</a></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">spectrumanalyser.h Example File</h1> <span class="subtitle">multimedia/spectrum/app/spectrumanalyser.h</span> <!-- $$$multimedia/spectrum/app/spectrumanalyser.h-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">#ifndef SPECTRUMANALYSER_H</span> <span class="preprocessor">#define SPECTRUMANALYSER_H</span> <span class="preprocessor">#include <QByteArray></span> <span class="preprocessor">#include <QObject></span> <span class="preprocessor">#include <QVector></span> <span class="preprocessor">#ifdef DUMP_SPECTRUMANALYSER</span> <span class="preprocessor">#include <QDir></span> <span class="preprocessor">#include <QFile></span> <span class="preprocessor">#include <QTextStream></span> <span class="preprocessor">#endif</span> <span class="preprocessor">#include "frequencyspectrum.h"</span> <span class="preprocessor">#include "spectrum.h"</span> <span class="preprocessor">#ifndef DISABLE_FFT</span> <span class="preprocessor">#include "FFTRealFixLenParam.h"</span> <span class="preprocessor">#endif</span> QT_FORWARD_DECLARE_CLASS(<span class="type">QAudioFormat</span>) QT_FORWARD_DECLARE_CLASS(<span class="type">QThread</span>) <span class="keyword">class</span> FFTRealWrapper; <span class="keyword">class</span> SpectrumAnalyserThreadPrivate; <span class="comment">/** * Implementation of the spectrum analysis which can be run in a * separate thread. */</span> <span class="keyword">class</span> SpectrumAnalyserThread : <span class="keyword">public</span> <span class="type">QObject</span> { Q_OBJECT <span class="keyword">public</span>: SpectrumAnalyserThread(<span class="type">QObject</span> <span class="operator">*</span>parent); <span class="operator">~</span>SpectrumAnalyserThread(); <span class="keyword">public</span> <span class="keyword">slots</span>: <span class="type">void</span> setWindowFunction(WindowFunction type); <span class="type">void</span> calculateSpectrum(<span class="keyword">const</span> <span class="type">QByteArray</span> <span class="operator">&</span>buffer<span class="operator">,</span> <span class="type">int</span> inputFrequency<span class="operator">,</span> <span class="type">int</span> bytesPerSample); <span class="keyword">signals</span>: <span class="type">void</span> calculationComplete(<span class="keyword">const</span> FrequencySpectrum <span class="operator">&</span>spectrum); <span class="keyword">private</span>: <span class="type">void</span> calculateWindow(); <span class="keyword">private</span>: <span class="preprocessor">#ifndef DISABLE_FFT</span> FFTRealWrapper<span class="operator">*</span> m_fft; <span class="preprocessor">#endif</span> <span class="keyword">const</span> <span class="type">int</span> m_numSamples; WindowFunction m_windowFunction; <span class="preprocessor">#ifdef DISABLE_FFT</span> <span class="keyword">typedef</span> <span class="type">qreal</span> DataType; <span class="preprocessor">#else</span> <span class="keyword">typedef</span> FFTRealFixLenParam<span class="operator">::</span>DataType DataType; <span class="preprocessor">#endif</span> <span class="type">QVector</span><span class="operator"><</span>DataType<span class="operator">></span> m_window; <span class="type">QVector</span><span class="operator"><</span>DataType<span class="operator">></span> m_input; <span class="type">QVector</span><span class="operator"><</span>DataType<span class="operator">></span> m_output; FrequencySpectrum m_spectrum; <span class="preprocessor">#ifdef SPECTRUM_ANALYSER_SEPARATE_THREAD</span> <span class="type">QThread</span><span class="operator">*</span> m_thread; <span class="preprocessor">#endif</span> }; <span class="comment">/** * Class which performs frequency spectrum analysis on a window of * audio samples, provided to it by the Engine. */</span> <span class="keyword">class</span> SpectrumAnalyser : <span class="keyword">public</span> <span class="type">QObject</span> { Q_OBJECT <span class="keyword">public</span>: SpectrumAnalyser(<span class="type">QObject</span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>); <span class="operator">~</span>SpectrumAnalyser(); <span class="preprocessor">#ifdef DUMP_SPECTRUMANALYSER</span> <span class="type">void</span> setOutputPath(<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>outputPath); <span class="preprocessor">#endif</span> <span class="keyword">public</span>: <span class="comment">/* * Set the windowing function which is applied before calculating the FFT */</span> <span class="type">void</span> setWindowFunction(WindowFunction type); <span class="comment">/* * Calculate a frequency spectrum * * \param buffer Audio data * \param format Format of audio data * * Frequency spectrum is calculated asynchronously. The result is returned * via the spectrumChanged signal. * * An ongoing calculation can be cancelled by calling cancelCalculation(). * */</span> <span class="type">void</span> calculate(<span class="keyword">const</span> <span class="type">QByteArray</span> <span class="operator">&</span>buffer<span class="operator">,</span> <span class="keyword">const</span> <span class="type">QAudioFormat</span> <span class="operator">&</span>format); <span class="comment">/* * Check whether the object is ready to perform another calculation */</span> bool isReady() <span class="keyword">const</span>; <span class="comment">/* * Cancel an ongoing calculation * * Note that cancelling is asynchronous. */</span> <span class="type">void</span> cancelCalculation(); <span class="keyword">signals</span>: <span class="type">void</span> spectrumChanged(<span class="keyword">const</span> FrequencySpectrum <span class="operator">&</span>spectrum); <span class="keyword">private</span> <span class="keyword">slots</span>: <span class="type">void</span> calculationComplete(<span class="keyword">const</span> FrequencySpectrum <span class="operator">&</span>spectrum); <span class="keyword">private</span>: <span class="type">void</span> calculateWindow(); <span class="keyword">private</span>: SpectrumAnalyserThread<span class="operator">*</span> m_thread; <span class="keyword">enum</span> State { Idle<span class="operator">,</span> Busy<span class="operator">,</span> Cancelled }; State m_state; <span class="preprocessor">#ifdef DUMP_SPECTRUMANALYSER</span> <span class="type">QDir</span> m_outputDir; <span class="type">int</span> m_count; <span class="type">QFile</span> m_textFile; <span class="type">QTextStream</span> m_textStream; <span class="preprocessor">#endif</span> }; <span class="preprocessor">#endif // SPECTRUMANALYSER_H</span> </pre> </div> <!-- @@@multimedia/spectrum/app/spectrumanalyser.h --> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 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>