<?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>utils.cpp Example File | Qt Multimedia 5.12.6</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 >utils.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtmultimedia-index.html">Qt 5.12.6 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">utils.cpp Example File</h1> <span class="subtitle">multimedia/spectrum/app/utils.cpp</span> <!-- $$$multimedia/spectrum/app/utils.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 <QAudioFormat></span> <span class="preprocessor">#include "utils.h"</span> <span class="type">qint64</span> audioDuration(<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">qint64</span> bytes) { <span class="keyword">return</span> (bytes <span class="operator">*</span> <span class="number">1000000</span>) <span class="operator">/</span> (format<span class="operator">.</span>sampleRate() <span class="operator">*</span> format<span class="operator">.</span>channelCount() <span class="operator">*</span> (format<span class="operator">.</span>sampleSize() <span class="operator">/</span> <span class="number">8</span>)); } <span class="type">qint64</span> audioLength(<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">qint64</span> microSeconds) { <span class="type">qint64</span> result <span class="operator">=</span> (format<span class="operator">.</span>sampleRate() <span class="operator">*</span> format<span class="operator">.</span>channelCount() <span class="operator">*</span> (format<span class="operator">.</span>sampleSize() <span class="operator">/</span> <span class="number">8</span>)) <span class="operator">*</span> microSeconds <span class="operator">/</span> <span class="number">1000000</span>; result <span class="operator">-</span><span class="operator">=</span> result <span class="operator">%</span> (format<span class="operator">.</span>channelCount() <span class="operator">*</span> format<span class="operator">.</span>sampleSize()); <span class="keyword">return</span> result; } <span class="type">qreal</span> nyquistFrequency(<span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format) { <span class="keyword">return</span> format<span class="operator">.</span>sampleRate() <span class="operator">/</span> <span class="number">2</span>; } <span class="type">QString</span> formatToString(<span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format) { <span class="type">QString</span> result; <span class="keyword">if</span> (<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span>() <span class="operator">!</span><span class="operator">=</span> format) { <span class="keyword">if</span> (format<span class="operator">.</span>codec() <span class="operator">=</span><span class="operator">=</span> <span class="string">"audio/pcm"</span>) { Q_ASSERT(format<span class="operator">.</span>sampleType() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>SignedInt); <span class="keyword">const</span> <span class="type">QString</span> formatEndian <span class="operator">=</span> (format<span class="operator">.</span>byteOrder() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>LittleEndian) <span class="operator">?</span> <span class="type">QString</span>(<span class="string">"LE"</span>) : <span class="type">QString</span>(<span class="string">"BE"</span>); <span class="type">QString</span> formatType; <span class="keyword">switch</span> (format<span class="operator">.</span>sampleType()) { <span class="keyword">case</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>SignedInt: formatType <span class="operator">=</span> <span class="string">"signed"</span>; <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>UnSignedInt: formatType <span class="operator">=</span> <span class="string">"unsigned"</span>; <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>Float: formatType <span class="operator">=</span> <span class="string">"float"</span>; <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>Unknown: formatType <span class="operator">=</span> <span class="string">"unknown"</span>; <span class="keyword">break</span>; } <span class="type">QString</span> formatChannels <span class="operator">=</span> <span class="type">QString</span>(<span class="string">"%1 channels"</span>)<span class="operator">.</span>arg(format<span class="operator">.</span>channelCount()); <span class="keyword">switch</span> (format<span class="operator">.</span>channelCount()) { <span class="keyword">case</span> <span class="number">1</span>: formatChannels <span class="operator">=</span> <span class="string">"mono"</span>; <span class="keyword">break</span>; <span class="keyword">case</span> <span class="number">2</span>: formatChannels <span class="operator">=</span> <span class="string">"stereo"</span>; <span class="keyword">break</span>; } result <span class="operator">=</span> <span class="type">QString</span>(<span class="string">"%1 Hz %2 bit %3 %4 %5"</span>) <span class="operator">.</span>arg(format<span class="operator">.</span>sampleRate()) <span class="operator">.</span>arg(format<span class="operator">.</span>sampleSize()) <span class="operator">.</span>arg(formatType) <span class="operator">.</span>arg(formatEndian) <span class="operator">.</span>arg(formatChannels); } <span class="keyword">else</span> { result <span class="operator">=</span> format<span class="operator">.</span>codec(); } } <span class="keyword">return</span> result; } bool isPCM(<span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format) { <span class="keyword">return</span> (format<span class="operator">.</span>codec() <span class="operator">=</span><span class="operator">=</span> <span class="string">"audio/pcm"</span>); } bool isPCMS16LE(<span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format) { <span class="keyword">return</span> isPCM(format) <span class="operator">&</span><span class="operator">&</span> format<span class="operator">.</span>sampleType() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>SignedInt <span class="operator">&</span><span class="operator">&</span> format<span class="operator">.</span>sampleSize() <span class="operator">=</span><span class="operator">=</span> <span class="number">16</span> <span class="operator">&</span><span class="operator">&</span> format<span class="operator">.</span>byteOrder() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>LittleEndian; } <span class="keyword">const</span> <span class="type">qint16</span> PCMS16MaxValue <span class="operator">=</span> <span class="number">32767</span>; <span class="keyword">const</span> <span class="type">quint16</span> PCMS16MaxAmplitude <span class="operator">=</span> <span class="number">32768</span>; <span class="comment">// because minimum is -32768</span> <span class="type">qreal</span> pcmToReal(<span class="type">qint16</span> pcm) { <span class="keyword">return</span> <span class="type">qreal</span>(pcm) <span class="operator">/</span> PCMS16MaxAmplitude; } <span class="type">qint16</span> realToPcm(<span class="type">qreal</span> real) { <span class="keyword">return</span> real <span class="operator">*</span> PCMS16MaxValue; } </pre> </div> <!-- @@@multimedia/spectrum/app/utils.cpp --> </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>