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<h1 class="title">wavfile.cpp Example File</h1>
<span class="small-subtitle">demos/spectrum/app/wavfile.cpp</span>
<!-- $$$demos/spectrum/app/wavfile.cpp-description -->
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<pre class="cpp"> <span class="comment">/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** You may use this file under the terms of the BSD license as follows:
**
** &quot;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
** &quot;AS IS&quot; 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.&quot;
**
** $QT_END_LICENSE$
**
****************************************************************************/</span>
<span class="preprocessor">#include &lt;QtCore/qendian.h&gt;</span>
<span class="preprocessor">#include &lt;QVector&gt;</span>
<span class="preprocessor">#include &lt;QDebug&gt;</span>
<span class="preprocessor">#include &quot;utils.h&quot;</span>
<span class="preprocessor">#include &quot;wavfile.h&quot;</span>
<span class="keyword">struct</span> chunk
{
<span class="type">char</span> id<span class="operator">[</span><span class="number">4</span><span class="operator">]</span>;
<span class="type"><a href="qtglobal.html#quint32-typedef">quint32</a></span> size;
};
<span class="keyword">struct</span> RIFFHeader
{
chunk descriptor; <span class="comment">// &quot;RIFF&quot;</span>
<span class="type">char</span> type<span class="operator">[</span><span class="number">4</span><span class="operator">]</span>; <span class="comment">// &quot;WAVE&quot;</span>
};
<span class="keyword">struct</span> WAVEHeader
{
chunk descriptor;
<span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span> audioFormat;
<span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span> numChannels;
<span class="type"><a href="qtglobal.html#quint32-typedef">quint32</a></span> sampleRate;
<span class="type"><a href="qtglobal.html#quint32-typedef">quint32</a></span> byteRate;
<span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span> blockAlign;
<span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span> bitsPerSample;
};
<span class="keyword">struct</span> DATAHeader
{
chunk descriptor;
};
<span class="keyword">struct</span> CombinedHeader
{
RIFFHeader riff;
WAVEHeader wave;
};
WavFile<span class="operator">::</span>WavFile(<span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>parent)
: <span class="type"><a href="qfile.html">QFile</a></span>(parent)
<span class="operator">,</span> m_headerLength(<span class="number">0</span>)
{
}
<span class="type">bool</span> WavFile<span class="operator">::</span>open(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&amp;</span>fileName)
{
close();
setFileName(fileName);
<span class="keyword">return</span> <span class="type"><a href="qfile.html">QFile</a></span><span class="operator">::</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>ReadOnly) <span class="operator">&amp;</span><span class="operator">&amp;</span> readHeader();
}
<span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&amp;</span>WavFile<span class="operator">::</span>fileFormat() <span class="keyword">const</span>
{
<span class="keyword">return</span> m_fileFormat;
}
<span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> WavFile<span class="operator">::</span>headerLength() <span class="keyword">const</span>
{
<span class="keyword">return</span> m_headerLength;
}
<span class="type">bool</span> WavFile<span class="operator">::</span>readHeader()
{
seek(<span class="number">0</span>);
CombinedHeader header;
<span class="type">bool</span> result <span class="operator">=</span> read(<span class="keyword">reinterpret_cast</span><span class="operator">&lt;</span><span class="type">char</span> <span class="operator">*</span><span class="operator">&gt;</span>(<span class="operator">&amp;</span>header)<span class="operator">,</span> <span class="keyword">sizeof</span>(CombinedHeader)) <span class="operator">=</span><span class="operator">=</span> <span class="keyword">sizeof</span>(CombinedHeader);
<span class="keyword">if</span> (result) {
<span class="keyword">if</span> ((memcmp(<span class="operator">&amp;</span>header<span class="operator">.</span>riff<span class="operator">.</span>descriptor<span class="operator">.</span>id<span class="operator">,</span> <span class="string">&quot;RIFF&quot;</span><span class="operator">,</span> <span class="number">4</span>) <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>
<span class="operator">|</span><span class="operator">|</span> memcmp(<span class="operator">&amp;</span>header<span class="operator">.</span>riff<span class="operator">.</span>descriptor<span class="operator">.</span>id<span class="operator">,</span> <span class="string">&quot;RIFX&quot;</span><span class="operator">,</span> <span class="number">4</span>) <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>)
<span class="operator">&amp;</span><span class="operator">&amp;</span> memcmp(<span class="operator">&amp;</span>header<span class="operator">.</span>riff<span class="operator">.</span>type<span class="operator">,</span> <span class="string">&quot;WAVE&quot;</span><span class="operator">,</span> <span class="number">4</span>) <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>
<span class="operator">&amp;</span><span class="operator">&amp;</span> memcmp(<span class="operator">&amp;</span>header<span class="operator">.</span>wave<span class="operator">.</span>descriptor<span class="operator">.</span>id<span class="operator">,</span> <span class="string">&quot;fmt &quot;</span><span class="operator">,</span> <span class="number">4</span>) <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>
<span class="operator">&amp;</span><span class="operator">&amp;</span> (header<span class="operator">.</span>wave<span class="operator">.</span>audioFormat <span class="operator">=</span><span class="operator">=</span> <span class="number">1</span> <span class="operator">|</span><span class="operator">|</span> header<span class="operator">.</span>wave<span class="operator">.</span>audioFormat <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>)) {
<span class="comment">// Read off remaining header information</span>
DATAHeader dataHeader;
<span class="keyword">if</span> (<a href="qtendian.html#qFromLittleEndian">qFromLittleEndian</a><span class="operator">&lt;</span><span class="type"><a href="qtglobal.html#quint32-typedef">quint32</a></span><span class="operator">&gt;</span>(header<span class="operator">.</span>wave<span class="operator">.</span>descriptor<span class="operator">.</span>size) <span class="operator">&gt;</span> <span class="keyword">sizeof</span>(WAVEHeader)) {
<span class="comment">// Extended data available</span>
<span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span> extraFormatBytes;
<span class="keyword">if</span> (peek((<span class="type">char</span><span class="operator">*</span>)<span class="operator">&amp;</span>extraFormatBytes<span class="operator">,</span> <span class="keyword">sizeof</span>(<span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span>)) <span class="operator">!</span><span class="operator">=</span> <span class="keyword">sizeof</span>(<span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span>))
<span class="keyword">return</span> <span class="keyword">false</span>;
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> throwAwayBytes <span class="operator">=</span> <span class="keyword">sizeof</span>(<span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span>) <span class="operator">+</span> <a href="qtendian.html#qFromLittleEndian">qFromLittleEndian</a><span class="operator">&lt;</span><span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span><span class="operator">&gt;</span>(extraFormatBytes);
<span class="keyword">if</span> (read(throwAwayBytes)<span class="operator">.</span>size() <span class="operator">!</span><span class="operator">=</span> throwAwayBytes)
<span class="keyword">return</span> <span class="keyword">false</span>;
}
<span class="keyword">if</span> (read((<span class="type">char</span><span class="operator">*</span>)<span class="operator">&amp;</span>dataHeader<span class="operator">,</span> <span class="keyword">sizeof</span>(DATAHeader)) <span class="operator">!</span><span class="operator">=</span> <span class="keyword">sizeof</span>(DATAHeader))
<span class="keyword">return</span> <span class="keyword">false</span>;
<span class="comment">// Establish format</span>
<span class="keyword">if</span> (memcmp(<span class="operator">&amp;</span>header<span class="operator">.</span>riff<span class="operator">.</span>descriptor<span class="operator">.</span>id<span class="operator">,</span> <span class="string">&quot;RIFF&quot;</span><span class="operator">,</span> <span class="number">4</span>) <span class="operator">=</span><span class="operator">=</span> <span class="number">0</span>)
m_fileFormat<span class="operator">.</span>setByteOrder(<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>LittleEndian);
<span class="keyword">else</span>
m_fileFormat<span class="operator">.</span>setByteOrder(<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>BigEndian);
<span class="type">int</span> bps <span class="operator">=</span> <a href="qtendian.html#qFromLittleEndian">qFromLittleEndian</a><span class="operator">&lt;</span><span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span><span class="operator">&gt;</span>(header<span class="operator">.</span>wave<span class="operator">.</span>bitsPerSample);
m_fileFormat<span class="operator">.</span>setChannels(<a href="qtendian.html#qFromLittleEndian">qFromLittleEndian</a><span class="operator">&lt;</span><span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span><span class="operator">&gt;</span>(header<span class="operator">.</span>wave<span class="operator">.</span>numChannels));
m_fileFormat<span class="operator">.</span>setCodec(<span class="string">&quot;audio/pcm&quot;</span>);
m_fileFormat<span class="operator">.</span>setFrequency(<a href="qtendian.html#qFromLittleEndian">qFromLittleEndian</a><span class="operator">&lt;</span><span class="type"><a href="qtglobal.html#quint32-typedef">quint32</a></span><span class="operator">&gt;</span>(header<span class="operator">.</span>wave<span class="operator">.</span>sampleRate));
m_fileFormat<span class="operator">.</span>setSampleSize(<a href="qtendian.html#qFromLittleEndian">qFromLittleEndian</a><span class="operator">&lt;</span><span class="type"><a href="qtglobal.html#quint16-typedef">quint16</a></span><span class="operator">&gt;</span>(header<span class="operator">.</span>wave<span class="operator">.</span>bitsPerSample));
m_fileFormat<span class="operator">.</span>setSampleType(bps <span class="operator">=</span><span class="operator">=</span> <span class="number">8</span> <span class="operator">?</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>UnSignedInt : <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>SignedInt);
} <span class="keyword">else</span> {
result <span class="operator">=</span> <span class="keyword">false</span>;
}
}
m_headerLength <span class="operator">=</span> pos();
<span class="keyword">return</span> result;
}</pre>
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<!-- @@@demos/spectrum/app/wavfile.cpp -->
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