<?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>engine.h 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 >engine.h 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">engine.h Example File</h1> <span class="subtitle">multimedia/spectrum/app/engine.h</span> <!-- $$$multimedia/spectrum/app/engine.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 ENGINE_H</span> <span class="preprocessor">#define ENGINE_H</span> <span class="preprocessor">#include "spectrum.h"</span> <span class="preprocessor">#include "spectrumanalyser.h"</span> <span class="preprocessor">#include "wavfile.h"</span> <span class="preprocessor">#include <QAudioDeviceInfo></span> <span class="preprocessor">#include <QAudioFormat></span> <span class="preprocessor">#include <QBuffer></span> <span class="preprocessor">#include <QByteArray></span> <span class="preprocessor">#include <QDir></span> <span class="preprocessor">#include <QObject></span> <span class="preprocessor">#include <QVector></span> <span class="preprocessor">#ifdef DUMP_CAPTURED_AUDIO</span> <span class="preprocessor">#define DUMP_DATA</span> <span class="preprocessor">#endif</span> <span class="preprocessor">#ifdef DUMP_SPECTRUM</span> <span class="preprocessor">#define DUMP_DATA</span> <span class="preprocessor">#endif</span> <span class="keyword">class</span> FrequencySpectrum; <span class="keyword">class</span> <span class="type"><a href="qaudioinput.html">QAudioInput</a></span>; <span class="keyword">class</span> <span class="type"><a href="qaudiooutput.html">QAudioOutput</a></span>; <span class="comment">/** * This class interfaces with the Qt Multimedia audio classes, and also with * the SpectrumAnalyser class. Its role is to manage the capture and playback * of audio data, meanwhile performing real-time analysis of the audio level * and frequency spectrum. */</span> <span class="keyword">class</span> Engine : <span class="keyword">public</span> <span class="type">QObject</span> { Q_OBJECT <span class="keyword">public</span>: <span class="keyword">explicit</span> Engine(<span class="type">QObject</span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>); <span class="operator">~</span>Engine(); <span class="keyword">const</span> <span class="type">QList</span><span class="operator"><</span><span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">></span> <span class="operator">&</span>availableAudioInputDevices() <span class="keyword">const</span> { <span class="keyword">return</span> m_availableAudioInputDevices; } <span class="keyword">const</span> <span class="type">QList</span><span class="operator"><</span><span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">></span> <span class="operator">&</span>availableAudioOutputDevices() <span class="keyword">const</span> { <span class="keyword">return</span> m_availableAudioOutputDevices; } <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>Mode mode() <span class="keyword">const</span> { <span class="keyword">return</span> m_mode; } <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State state() <span class="keyword">const</span> { <span class="keyword">return</span> m_state; } <span class="comment">/** * \return Current audio format * \note May be QAudioFormat() if engine is not initialized */</span> <span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">&</span> format() <span class="keyword">const</span> { <span class="keyword">return</span> m_format; } <span class="comment">/** * Stop any ongoing recording or playback, and reset to ground state. */</span> <span class="type">void</span> reset(); <span class="comment">/** * Load data from WAV file */</span> bool loadFile(<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>fileName); <span class="comment">/** * Generate tone */</span> bool generateTone(<span class="keyword">const</span> Tone <span class="operator">&</span>tone); <span class="comment">/** * Generate tone */</span> bool generateSweptTone(<span class="type">qreal</span> amplitude); <span class="comment">/** * Initialize for recording */</span> bool initializeRecord(); <span class="comment">/** * Position of the audio input device. * \return Position in bytes. */</span> <span class="type">qint64</span> recordPosition() <span class="keyword">const</span> { <span class="keyword">return</span> m_recordPosition; } <span class="comment">/** * RMS level of the most recently processed set of audio samples. * \return Level in range (0.0, 1.0) */</span> <span class="type">qreal</span> rmsLevel() <span class="keyword">const</span> { <span class="keyword">return</span> m_rmsLevel; } <span class="comment">/** * Peak level of the most recently processed set of audio samples. * \return Level in range (0.0, 1.0) */</span> <span class="type">qreal</span> peakLevel() <span class="keyword">const</span> { <span class="keyword">return</span> m_peakLevel; } <span class="comment">/** * Position of the audio output device. * \return Position in bytes. */</span> <span class="type">qint64</span> playPosition() <span class="keyword">const</span> { <span class="keyword">return</span> m_playPosition; } <span class="comment">/** * Length of the internal engine buffer. * \return Buffer length in bytes. */</span> <span class="type">qint64</span> bufferLength() <span class="keyword">const</span>; <span class="comment">/** * Amount of data held in the buffer. * \return Data length in bytes. */</span> <span class="type">qint64</span> dataLength() <span class="keyword">const</span> { <span class="keyword">return</span> m_dataLength; } <span class="comment">/** * Set window function applied to audio data before spectral analysis. */</span> <span class="type">void</span> setWindowFunction(WindowFunction type); <span class="keyword">public</span> <span class="keyword">slots</span>: <span class="type">void</span> startRecording(); <span class="type">void</span> startPlayback(); <span class="type">void</span> suspend(); <span class="type">void</span> setAudioInputDevice(<span class="keyword">const</span> <span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span> <span class="operator">&</span>device); <span class="type">void</span> setAudioOutputDevice(<span class="keyword">const</span> <span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span> <span class="operator">&</span>device); <span class="keyword">signals</span>: <span class="type">void</span> stateChanged(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>Mode mode<span class="operator">,</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State state); <span class="comment">/** * Informational message for non-modal display */</span> <span class="type">void</span> infoMessage(<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>message<span class="operator">,</span> <span class="type">int</span> durationMs); <span class="comment">/** * Error message for modal display */</span> <span class="type">void</span> errorMessage(<span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>heading<span class="operator">,</span> <span class="keyword">const</span> <span class="type">QString</span> <span class="operator">&</span>detail); <span class="comment">/** * Format of audio data has changed */</span> <span class="type">void</span> formatChanged(<span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format); <span class="comment">/** * Length of buffer has changed. * \param duration Duration in microseconds */</span> <span class="type">void</span> bufferLengthChanged(<span class="type">qint64</span> duration); <span class="comment">/** * Amount of data in buffer has changed. * \param Length of data in bytes */</span> <span class="type">void</span> dataLengthChanged(<span class="type">qint64</span> duration); <span class="comment">/** * Position of the audio input device has changed. * \param position Position in bytes */</span> <span class="type">void</span> recordPositionChanged(<span class="type">qint64</span> position); <span class="comment">/** * Position of the audio output device has changed. * \param position Position in bytes */</span> <span class="type">void</span> playPositionChanged(<span class="type">qint64</span> position); <span class="comment">/** * Level changed * \param rmsLevel RMS level in range 0.0 - 1.0 * \param peakLevel Peak level in range 0.0 - 1.0 * \param numSamples Number of audio samples analyzed */</span> <span class="type">void</span> levelChanged(<span class="type">qreal</span> rmsLevel<span class="operator">,</span> <span class="type">qreal</span> peakLevel<span class="operator">,</span> <span class="type">int</span> numSamples); <span class="comment">/** * Spectrum has changed. * \param position Position of start of window in bytes * \param length Length of window in bytes * \param spectrum Resulting frequency spectrum */</span> <span class="type">void</span> spectrumChanged(<span class="type">qint64</span> position<span class="operator">,</span> <span class="type">qint64</span> length<span class="operator">,</span> <span class="keyword">const</span> FrequencySpectrum <span class="operator">&</span>spectrum); <span class="comment">/** * Buffer containing audio data has changed. * \param position Position of start of buffer in bytes * \param buffer Buffer */</span> <span class="type">void</span> bufferChanged(<span class="type">qint64</span> position<span class="operator">,</span> <span class="type">qint64</span> length<span class="operator">,</span> <span class="keyword">const</span> <span class="type">QByteArray</span> <span class="operator">&</span>buffer); <span class="keyword">private</span> <span class="keyword">slots</span>: <span class="type">void</span> audioNotify(); <span class="type">void</span> audioStateChanged(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State state); <span class="type">void</span> audioDataReady(); <span class="type">void</span> spectrumChanged(<span class="keyword">const</span> FrequencySpectrum <span class="operator">&</span>spectrum); <span class="keyword">private</span>: <span class="type">void</span> resetAudioDevices(); bool initialize(); bool selectFormat(); <span class="type">void</span> stopRecording(); <span class="type">void</span> stopPlayback(); <span class="type">void</span> setState(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State state); <span class="type">void</span> setState(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>Mode mode<span class="operator">,</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State state); <span class="type">void</span> setFormat(<span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format); <span class="type">void</span> setRecordPosition(<span class="type">qint64</span> position<span class="operator">,</span> bool forceEmit <span class="operator">=</span> <span class="keyword">false</span>); <span class="type">void</span> setPlayPosition(<span class="type">qint64</span> position<span class="operator">,</span> bool forceEmit <span class="operator">=</span> <span class="keyword">false</span>); <span class="type">void</span> calculateLevel(<span class="type">qint64</span> position<span class="operator">,</span> <span class="type">qint64</span> length); <span class="type">void</span> calculateSpectrum(<span class="type">qint64</span> position); <span class="type">void</span> setLevel(<span class="type">qreal</span> rmsLevel<span class="operator">,</span> <span class="type">qreal</span> peakLevel<span class="operator">,</span> <span class="type">int</span> numSamples); <span class="preprocessor">#ifdef DUMP_DATA</span> <span class="type">void</span> createOutputDir(); <span class="type">QString</span> outputPath() <span class="keyword">const</span> { <span class="keyword">return</span> m_outputDir<span class="operator">.</span>path(); } <span class="preprocessor">#endif</span> <span class="preprocessor">#ifdef DUMP_CAPTURED_AUDIO</span> <span class="type">void</span> dumpData(); <span class="preprocessor">#endif</span> <span class="keyword">private</span>: <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>Mode m_mode; <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State m_state; bool m_generateTone; SweptTone m_tone; WavFile<span class="operator">*</span> m_file; <span class="comment">// We need a second file handle via which to read data into m_buffer</span> <span class="comment">// for analysis</span> WavFile<span class="operator">*</span> m_analysisFile; <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> m_format; <span class="keyword">const</span> <span class="type">QList</span><span class="operator"><</span><span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">></span> m_availableAudioInputDevices; <span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span> m_audioInputDevice; <span class="type"><a href="qaudioinput.html">QAudioInput</a></span><span class="operator">*</span> m_audioInput; <span class="type">QIODevice</span><span class="operator">*</span> m_audioInputIODevice; <span class="type">qint64</span> m_recordPosition; <span class="keyword">const</span> <span class="type">QList</span><span class="operator"><</span><span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">></span> m_availableAudioOutputDevices; <span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span> m_audioOutputDevice; <span class="type"><a href="qaudiooutput.html">QAudioOutput</a></span><span class="operator">*</span> m_audioOutput; <span class="type">qint64</span> m_playPosition; <span class="type">QBuffer</span> m_audioOutputIODevice; <span class="type">QByteArray</span> m_buffer; <span class="type">qint64</span> m_bufferPosition; <span class="type">qint64</span> m_bufferLength; <span class="type">qint64</span> m_dataLength; <span class="type">int</span> m_levelBufferLength; <span class="type">qreal</span> m_rmsLevel; <span class="type">qreal</span> m_peakLevel; <span class="type">int</span> m_spectrumBufferLength; <span class="type">QByteArray</span> m_spectrumBuffer; SpectrumAnalyser m_spectrumAnalyser; <span class="type">qint64</span> m_spectrumPosition; <span class="type">int</span> m_count; <span class="preprocessor">#ifdef DUMP_DATA</span> <span class="type">QDir</span> m_outputDir; <span class="preprocessor">#endif</span> }; <span class="preprocessor">#endif // ENGINE_H</span> </pre> </div> <!-- @@@multimedia/spectrum/app/engine.h --> </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>