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<h1 class="title">engine.cpp Example File</h1>
<span class="small-subtitle">demos/spectrum/app/engine.cpp</span>
<!-- $$$demos/spectrum/app/engine.cpp-description -->
<div class="descr"> <a name="details"></a>
<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:
**
** "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 "engine.h"</span>
<span class="preprocessor">#include "tonegenerator.h"</span>
<span class="preprocessor">#include "utils.h"</span>
<span class="preprocessor">#include <math.h></span>
<span class="preprocessor">#include <QCoreApplication></span>
<span class="preprocessor">#include <QMetaObject></span>
<span class="preprocessor">#include <QSet></span>
<span class="preprocessor">#include <QtMultimedia/QAudioInput></span>
<span class="preprocessor">#include <QtMultimedia/QAudioOutput></span>
<span class="preprocessor">#include <QDebug></span>
<span class="preprocessor">#include <QThread></span>
<span class="preprocessor">#include <QFile></span>
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="comment">// Constants</span>
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> BufferDurationUs <span class="operator">=</span> <span class="number">10</span> <span class="operator">*</span> <span class="number">1000000</span>;
<span class="keyword">const</span> <span class="type">int</span> NotifyIntervalMs <span class="operator">=</span> <span class="number">100</span>;
<span class="comment">// Size of the level calculation window in microseconds</span>
<span class="keyword">const</span> <span class="type">int</span> LevelWindowUs <span class="operator">=</span> <span class="number">0.1</span> <span class="operator">*</span> <span class="number">1000000</span>;
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="comment">// Helper functions</span>
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="type"><a href="qdebug.html">QDebug</a></span><span class="operator">&</span> <span class="keyword">operator</span><span class="operator"><</span><span class="operator"><</span>(<span class="type"><a href="qdebug.html">QDebug</a></span> <span class="operator">&</span>debug<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> <span class="operator">&</span>format)
{
debug <span class="operator"><</span><span class="operator"><</span> format<span class="operator">.</span>frequency() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Hz"</span>
<span class="operator"><</span><span class="operator"><</span> format<span class="operator">.</span>channels() <span class="operator"><</span><span class="operator"><</span> <span class="string">"channels"</span>;
<span class="keyword">return</span> debug;
}
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="comment">// Constructor and destructor</span>
<span class="comment">//-----------------------------------------------------------------------------</span>
Engine<span class="operator">::</span>Engine(<span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>parent)
: <span class="type"><a href="qobject.html">QObject</a></span>(parent)
<span class="operator">,</span> m_mode(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioInput)
<span class="operator">,</span> m_state(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>StoppedState)
<span class="operator">,</span> m_generateTone(<span class="keyword">false</span>)
<span class="operator">,</span> m_file(<span class="number">0</span>)
<span class="operator">,</span> m_analysisFile(<span class="number">0</span>)
<span class="operator">,</span> m_availableAudioInputDevices
(<span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">::</span>availableDevices(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioInput))
<span class="operator">,</span> m_audioInputDevice(<span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">::</span>defaultInputDevice())
<span class="operator">,</span> m_audioInput(<span class="number">0</span>)
<span class="operator">,</span> m_audioInputIODevice(<span class="number">0</span>)
<span class="operator">,</span> m_recordPosition(<span class="number">0</span>)
<span class="operator">,</span> m_availableAudioOutputDevices
(<span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">::</span>availableDevices(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioOutput))
<span class="operator">,</span> m_audioOutputDevice(<span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span><span class="operator">::</span>defaultOutputDevice())
<span class="operator">,</span> m_audioOutput(<span class="number">0</span>)
<span class="operator">,</span> m_playPosition(<span class="number">0</span>)
<span class="operator">,</span> m_bufferPosition(<span class="number">0</span>)
<span class="operator">,</span> m_bufferLength(<span class="number">0</span>)
<span class="operator">,</span> m_dataLength(<span class="number">0</span>)
<span class="operator">,</span> m_levelBufferLength(<span class="number">0</span>)
<span class="operator">,</span> m_rmsLevel(<span class="number">0.0</span>)
<span class="operator">,</span> m_peakLevel(<span class="number">0.0</span>)
<span class="operator">,</span> m_spectrumBufferLength(<span class="number">0</span>)
<span class="operator">,</span> m_spectrumAnalyser()
<span class="operator">,</span> m_spectrumPosition(<span class="number">0</span>)
<span class="operator">,</span> m_count(<span class="number">0</span>)
{
<a href="qmetatype.html#qRegisterMetaType">qRegisterMetaType</a><span class="operator"><</span>FrequencySpectrum<span class="operator">></span>(<span class="string">"FrequencySpectrum"</span>);
<a href="qmetatype.html#qRegisterMetaType">qRegisterMetaType</a><span class="operator"><</span>WindowFunction<span class="operator">></span>(<span class="string">"WindowFunction"</span>);
CHECKED_CONNECT(<span class="operator">&</span>m_spectrumAnalyser<span class="operator">,</span>
SIGNAL(spectrumChanged(FrequencySpectrum))<span class="operator">,</span>
<span class="keyword">this</span><span class="operator">,</span>
SLOT(spectrumChanged(FrequencySpectrum)));
initialize();
<span class="preprocessor">#ifdef DUMP_DATA</span>
createOutputDir();
<span class="preprocessor">#endif</span>
<span class="preprocessor">#ifdef DUMP_SPECTRUM</span>
m_spectrumAnalyser<span class="operator">.</span>setOutputPath(outputPath());
<span class="preprocessor">#endif</span>
}
Engine<span class="operator">::</span><span class="operator">~</span>Engine()
{
}
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="comment">// Public functions</span>
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="type">bool</span> Engine<span class="operator">::</span>loadFile(<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> <span class="operator">&</span>fileName)
{
reset();
<span class="type">bool</span> result <span class="operator">=</span> <span class="keyword">false</span>;
Q_ASSERT(<span class="operator">!</span>m_generateTone);
Q_ASSERT(<span class="operator">!</span>m_file);
Q_ASSERT(<span class="operator">!</span>fileName<span class="operator">.</span>isEmpty());
m_file <span class="operator">=</span> <span class="keyword">new</span> WavFile(<span class="keyword">this</span>);
<span class="keyword">if</span> (m_file<span class="operator">-</span><span class="operator">></span>open(fileName)) {
<span class="keyword">if</span> (isPCMS16LE(m_file<span class="operator">-</span><span class="operator">></span>fileFormat())) {
result <span class="operator">=</span> initialize();
} <span class="keyword">else</span> {
<span class="keyword">emit</span> errorMessage(tr(<span class="string">"Audio format not supported"</span>)<span class="operator">,</span>
formatToString(m_file<span class="operator">-</span><span class="operator">></span>fileFormat()));
}
} <span class="keyword">else</span> {
<span class="keyword">emit</span> errorMessage(tr(<span class="string">"Could not open file"</span>)<span class="operator">,</span> fileName);
}
<span class="keyword">if</span> (result) {
m_analysisFile <span class="operator">=</span> <span class="keyword">new</span> WavFile(<span class="keyword">this</span>);
m_analysisFile<span class="operator">-</span><span class="operator">></span>open(fileName);
}
<span class="keyword">return</span> result;
}
<span class="type">bool</span> Engine<span class="operator">::</span>generateTone(<span class="keyword">const</span> Tone <span class="operator">&</span>tone)
{
reset();
Q_ASSERT(<span class="operator">!</span>m_generateTone);
Q_ASSERT(<span class="operator">!</span>m_file);
m_generateTone <span class="operator">=</span> <span class="keyword">true</span>;
m_tone <span class="operator">=</span> tone;
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::generateTone"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"startFreq"</span> <span class="operator"><</span><span class="operator"><</span> m_tone<span class="operator">.</span>startFreq
<span class="operator"><</span><span class="operator"><</span> <span class="string">"endFreq"</span> <span class="operator"><</span><span class="operator"><</span> m_tone<span class="operator">.</span>endFreq
<span class="operator"><</span><span class="operator"><</span> <span class="string">"amp"</span> <span class="operator"><</span><span class="operator"><</span> m_tone<span class="operator">.</span>amplitude;
<span class="keyword">return</span> initialize();
}
<span class="type">bool</span> Engine<span class="operator">::</span>generateSweptTone(<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> amplitude)
{
Q_ASSERT(<span class="operator">!</span>m_generateTone);
Q_ASSERT(<span class="operator">!</span>m_file);
m_generateTone <span class="operator">=</span> <span class="keyword">true</span>;
m_tone<span class="operator">.</span>startFreq <span class="operator">=</span> <span class="number">1</span>;
m_tone<span class="operator">.</span>endFreq <span class="operator">=</span> <span class="number">0</span>;
m_tone<span class="operator">.</span>amplitude <span class="operator">=</span> amplitude;
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::generateSweptTone"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"startFreq"</span> <span class="operator"><</span><span class="operator"><</span> m_tone<span class="operator">.</span>startFreq
<span class="operator"><</span><span class="operator"><</span> <span class="string">"amp"</span> <span class="operator"><</span><span class="operator"><</span> m_tone<span class="operator">.</span>amplitude;
<span class="keyword">return</span> initialize();
}
<span class="type">bool</span> Engine<span class="operator">::</span>initializeRecord()
{
reset();
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::initializeRecord"</span>;
Q_ASSERT(<span class="operator">!</span>m_generateTone);
Q_ASSERT(<span class="operator">!</span>m_file);
m_generateTone <span class="operator">=</span> <span class="keyword">false</span>;
m_tone <span class="operator">=</span> SweptTone();
<span class="keyword">return</span> initialize();
}
<span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> Engine<span class="operator">::</span>bufferLength() <span class="keyword">const</span>
{
<span class="keyword">return</span> m_file <span class="operator">?</span> m_file<span class="operator">-</span><span class="operator">></span>size() : m_bufferLength;
}
<span class="type">void</span> Engine<span class="operator">::</span>setWindowFunction(WindowFunction type)
{
m_spectrumAnalyser<span class="operator">.</span>setWindowFunction(type);
}
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="comment">// Public slots</span>
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="type">void</span> Engine<span class="operator">::</span>startRecording()
{
<span class="keyword">if</span> (m_audioInput) {
<span class="keyword">if</span> (<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioInput <span class="operator">=</span><span class="operator">=</span> m_mode <span class="operator">&</span><span class="operator">&</span>
<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>SuspendedState <span class="operator">=</span><span class="operator">=</span> m_state) {
m_audioInput<span class="operator">-</span><span class="operator">></span>resume();
} <span class="keyword">else</span> {
m_spectrumAnalyser<span class="operator">.</span>cancelCalculation();
spectrumChanged(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> FrequencySpectrum());
m_buffer<span class="operator">.</span>fill(<span class="number">0</span>);
setRecordPosition(<span class="number">0</span><span class="operator">,</span> <span class="keyword">true</span>);
stopPlayback();
m_mode <span class="operator">=</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioInput;
CHECKED_CONNECT(m_audioInput<span class="operator">,</span> SIGNAL(stateChanged(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State))<span class="operator">,</span>
<span class="keyword">this</span><span class="operator">,</span> SLOT(audioStateChanged(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State)));
CHECKED_CONNECT(m_audioInput<span class="operator">,</span> SIGNAL(notify())<span class="operator">,</span>
<span class="keyword">this</span><span class="operator">,</span> SLOT(audioNotify()));
m_count <span class="operator">=</span> <span class="number">0</span>;
m_dataLength <span class="operator">=</span> <span class="number">0</span>;
<span class="keyword">emit</span> dataLengthChanged(<span class="number">0</span>);
m_audioInputIODevice <span class="operator">=</span> m_audioInput<span class="operator">-</span><span class="operator">></span>start();
CHECKED_CONNECT(m_audioInputIODevice<span class="operator">,</span> SIGNAL(readyRead())<span class="operator">,</span>
<span class="keyword">this</span><span class="operator">,</span> SLOT(audioDataReady()));
}
}
}
<span class="type">void</span> Engine<span class="operator">::</span>startPlayback()
{
<span class="keyword">if</span> (m_audioOutput) {
<span class="keyword">if</span> (<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioOutput <span class="operator">=</span><span class="operator">=</span> m_mode <span class="operator">&</span><span class="operator">&</span>
<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>SuspendedState <span class="operator">=</span><span class="operator">=</span> m_state) {
<span class="preprocessor">#ifdef Q_OS_WIN</span>
<span class="comment">// The Windows backend seems to internally go back into ActiveState</span>
<span class="comment">// while still returning SuspendedState, so to ensure that it doesn't</span>
<span class="comment">// ignore the resume() call, we first re-suspend</span>
m_audioOutput<span class="operator">-</span><span class="operator">></span>suspend();
<span class="preprocessor">#endif</span>
m_audioOutput<span class="operator">-</span><span class="operator">></span>resume();
} <span class="keyword">else</span> {
m_spectrumAnalyser<span class="operator">.</span>cancelCalculation();
spectrumChanged(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> FrequencySpectrum());
setPlayPosition(<span class="number">0</span><span class="operator">,</span> <span class="keyword">true</span>);
stopRecording();
m_mode <span class="operator">=</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioOutput;
CHECKED_CONNECT(m_audioOutput<span class="operator">,</span> SIGNAL(stateChanged(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State))<span class="operator">,</span>
<span class="keyword">this</span><span class="operator">,</span> SLOT(audioStateChanged(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State)));
CHECKED_CONNECT(m_audioOutput<span class="operator">,</span> SIGNAL(notify())<span class="operator">,</span>
<span class="keyword">this</span><span class="operator">,</span> SLOT(audioNotify()));
m_count <span class="operator">=</span> <span class="number">0</span>;
<span class="keyword">if</span> (m_file) {
m_file<span class="operator">-</span><span class="operator">></span>seek(<span class="number">0</span>);
m_bufferPosition <span class="operator">=</span> <span class="number">0</span>;
m_dataLength <span class="operator">=</span> <span class="number">0</span>;
m_audioOutput<span class="operator">-</span><span class="operator">></span>start(m_file);
} <span class="keyword">else</span> {
m_audioOutputIODevice<span class="operator">.</span>close();
m_audioOutputIODevice<span class="operator">.</span>setBuffer(<span class="operator">&</span>m_buffer);
m_audioOutputIODevice<span class="operator">.</span>open(<span class="type"><a href="qiodevice.html">QIODevice</a></span><span class="operator">::</span>ReadOnly);
m_audioOutput<span class="operator">-</span><span class="operator">></span>start(<span class="operator">&</span>m_audioOutputIODevice);
}
}
}
}
<span class="type">void</span> Engine<span class="operator">::</span>suspend()
{
<span class="keyword">if</span> (<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>ActiveState <span class="operator">=</span><span class="operator">=</span> m_state <span class="operator">|</span><span class="operator">|</span>
<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>IdleState <span class="operator">=</span><span class="operator">=</span> m_state) {
<span class="keyword">switch</span> (m_mode) {
<span class="keyword">case</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioInput:
m_audioInput<span class="operator">-</span><span class="operator">></span>suspend();
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioOutput:
m_audioOutput<span class="operator">-</span><span class="operator">></span>suspend();
<span class="keyword">break</span>;
}
}
}
<span class="type">void</span> Engine<span class="operator">::</span>setAudioInputDevice(<span class="keyword">const</span> <span class="type"><a href="qaudiodeviceinfo.html">QAudioDeviceInfo</a></span> <span class="operator">&</span>device)
{
<span class="keyword">if</span> (device<span class="operator">.</span>deviceName() <span class="operator">!</span><span class="operator">=</span> m_audioInputDevice<span class="operator">.</span>deviceName()) {
m_audioInputDevice <span class="operator">=</span> device;
initialize();
}
}
<span class="type">void</span> Engine<span class="operator">::</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">if</span> (device<span class="operator">.</span>deviceName() <span class="operator">!</span><span class="operator">=</span> m_audioOutputDevice<span class="operator">.</span>deviceName()) {
m_audioOutputDevice <span class="operator">=</span> device;
initialize();
}
}
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="comment">// Private slots</span>
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="type">void</span> Engine<span class="operator">::</span>audioNotify()
{
<span class="keyword">switch</span> (m_mode) {
<span class="keyword">case</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioInput: {
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> recordPosition <span class="operator">=</span> <a href="qtglobal.html#qMin">qMin</a>(m_bufferLength<span class="operator">,</span> audioLength(m_format<span class="operator">,</span> m_audioInput<span class="operator">-</span><span class="operator">></span>processedUSecs()));
setRecordPosition(recordPosition);
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> levelPosition <span class="operator">=</span> m_dataLength <span class="operator">-</span> m_levelBufferLength;
<span class="keyword">if</span> (levelPosition <span class="operator">></span><span class="operator">=</span> <span class="number">0</span>)
calculateLevel(levelPosition<span class="operator">,</span> m_levelBufferLength);
<span class="keyword">if</span> (m_dataLength <span class="operator">></span><span class="operator">=</span> m_spectrumBufferLength) {
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> spectrumPosition <span class="operator">=</span> m_dataLength <span class="operator">-</span> m_spectrumBufferLength;
calculateSpectrum(spectrumPosition);
}
<span class="keyword">emit</span> bufferChanged(<span class="number">0</span><span class="operator">,</span> m_dataLength<span class="operator">,</span> m_buffer);
}
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioOutput: {
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> playPosition <span class="operator">=</span> audioLength(m_format<span class="operator">,</span> m_audioOutput<span class="operator">-</span><span class="operator">></span>processedUSecs());
setPlayPosition(<a href="qtglobal.html#qMin">qMin</a>(bufferLength()<span class="operator">,</span> playPosition));
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> levelPosition <span class="operator">=</span> playPosition <span class="operator">-</span> m_levelBufferLength;
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> spectrumPosition <span class="operator">=</span> playPosition <span class="operator">-</span> m_spectrumBufferLength;
<span class="keyword">if</span> (m_file) {
<span class="keyword">if</span> (levelPosition <span class="operator">></span> m_bufferPosition <span class="operator">|</span><span class="operator">|</span>
spectrumPosition <span class="operator">></span> m_bufferPosition <span class="operator">|</span><span class="operator">|</span>
<a href="qtglobal.html#qMax">qMax</a>(m_levelBufferLength<span class="operator">,</span> m_spectrumBufferLength) <span class="operator">></span> m_dataLength) {
m_bufferPosition <span class="operator">=</span> <span class="number">0</span>;
m_dataLength <span class="operator">=</span> <span class="number">0</span>;
<span class="comment">// Data needs to be read into m_buffer in order to be analysed</span>
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> readPos <span class="operator">=</span> <a href="qtglobal.html#qMax">qMax</a>(<span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span>(<span class="number">0</span>)<span class="operator">,</span> <a href="qtglobal.html#qMin">qMin</a>(levelPosition<span class="operator">,</span> spectrumPosition));
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> readEnd <span class="operator">=</span> <a href="qtglobal.html#qMin">qMin</a>(m_analysisFile<span class="operator">-</span><span class="operator">></span>size()<span class="operator">,</span> <a href="qtglobal.html#qMax">qMax</a>(levelPosition <span class="operator">+</span> m_levelBufferLength<span class="operator">,</span> spectrumPosition <span class="operator">+</span> m_spectrumBufferLength));
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> readLen <span class="operator">=</span> readEnd <span class="operator">-</span> readPos <span class="operator">+</span> audioLength(m_format<span class="operator">,</span> WaveformWindowDuration);
<a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::audioNotify [1]"</span>
<span class="operator"><</span><span class="operator"><</span> <span class="string">"analysisFileSize"</span> <span class="operator"><</span><span class="operator"><</span> m_analysisFile<span class="operator">-</span><span class="operator">></span>size()
<span class="operator"><</span><span class="operator"><</span> <span class="string">"readPos"</span> <span class="operator"><</span><span class="operator"><</span> readPos
<span class="operator"><</span><span class="operator"><</span> <span class="string">"readLen"</span> <span class="operator"><</span><span class="operator"><</span> readLen;
<span class="keyword">if</span> (m_analysisFile<span class="operator">-</span><span class="operator">></span>seek(readPos <span class="operator">+</span> m_analysisFile<span class="operator">-</span><span class="operator">></span>headerLength())) {
m_buffer<span class="operator">.</span>resize(readLen);
m_bufferPosition <span class="operator">=</span> readPos;
m_dataLength <span class="operator">=</span> m_analysisFile<span class="operator">-</span><span class="operator">></span>read(m_buffer<span class="operator">.</span>data()<span class="operator">,</span> readLen);
<a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::audioNotify [2]"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"bufferPosition"</span> <span class="operator"><</span><span class="operator"><</span> m_bufferPosition <span class="operator"><</span><span class="operator"><</span> <span class="string">"dataLength"</span> <span class="operator"><</span><span class="operator"><</span> m_dataLength;
} <span class="keyword">else</span> {
<a href="qtglobal.html#qDebug">qDebug</a>() <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::audioNotify [2]"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"file seek error"</span>;
}
<span class="keyword">emit</span> bufferChanged(m_bufferPosition<span class="operator">,</span> m_dataLength<span class="operator">,</span> m_buffer);
}
} <span class="keyword">else</span> {
<span class="keyword">if</span> (playPosition <span class="operator">></span><span class="operator">=</span> m_dataLength)
stopPlayback();
}
<span class="keyword">if</span> (levelPosition <span class="operator">></span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> levelPosition <span class="operator">+</span> m_levelBufferLength <span class="operator"><</span> m_bufferPosition <span class="operator">+</span> m_dataLength)
calculateLevel(levelPosition<span class="operator">,</span> m_levelBufferLength);
<span class="keyword">if</span> (spectrumPosition <span class="operator">></span><span class="operator">=</span> <span class="number">0</span> <span class="operator">&</span><span class="operator">&</span> spectrumPosition <span class="operator">+</span> m_spectrumBufferLength <span class="operator"><</span> m_bufferPosition <span class="operator">+</span> m_dataLength)
calculateSpectrum(spectrumPosition);
}
<span class="keyword">break</span>;
}
}
<span class="type">void</span> Engine<span class="operator">::</span>audioStateChanged(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State state)
{
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::audioStateChanged from"</span> <span class="operator"><</span><span class="operator"><</span> m_state
<span class="operator"><</span><span class="operator"><</span> <span class="string">"to"</span> <span class="operator"><</span><span class="operator"><</span> state;
<span class="keyword">if</span> (<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>IdleState <span class="operator">=</span><span class="operator">=</span> state <span class="operator">&</span><span class="operator">&</span> m_file <span class="operator">&</span><span class="operator">&</span> m_file<span class="operator">-</span><span class="operator">></span>pos() <span class="operator">=</span><span class="operator">=</span> m_file<span class="operator">-</span><span class="operator">></span>size()) {
stopPlayback();
} <span class="keyword">else</span> {
<span class="keyword">if</span> (<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>StoppedState <span class="operator">=</span><span class="operator">=</span> state) {
<span class="comment">// Check error</span>
<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>Error error <span class="operator">=</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>NoError;
<span class="keyword">switch</span> (m_mode) {
<span class="keyword">case</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioInput:
error <span class="operator">=</span> m_audioInput<span class="operator">-</span><span class="operator">></span>error();
<span class="keyword">break</span>;
<span class="keyword">case</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioOutput:
error <span class="operator">=</span> m_audioOutput<span class="operator">-</span><span class="operator">></span>error();
<span class="keyword">break</span>;
}
<span class="keyword">if</span> (<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>NoError <span class="operator">!</span><span class="operator">=</span> error) {
reset();
<span class="keyword">return</span>;
}
}
setState(state);
}
}
<span class="type">void</span> Engine<span class="operator">::</span>audioDataReady()
{
Q_ASSERT(<span class="number">0</span> <span class="operator">=</span><span class="operator">=</span> m_bufferPosition);
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> bytesReady <span class="operator">=</span> m_audioInput<span class="operator">-</span><span class="operator">></span>bytesReady();
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> bytesSpace <span class="operator">=</span> m_buffer<span class="operator">.</span>size() <span class="operator">-</span> m_dataLength;
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> bytesToRead <span class="operator">=</span> <a href="qtglobal.html#qMin">qMin</a>(bytesReady<span class="operator">,</span> bytesSpace);
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> bytesRead <span class="operator">=</span> m_audioInputIODevice<span class="operator">-</span><span class="operator">></span>read(
m_buffer<span class="operator">.</span>data() <span class="operator">+</span> m_dataLength<span class="operator">,</span>
bytesToRead);
<span class="keyword">if</span> (bytesRead) {
m_dataLength <span class="operator">+</span><span class="operator">=</span> bytesRead;
<span class="keyword">emit</span> dataLengthChanged(dataLength());
}
<span class="keyword">if</span> (m_buffer<span class="operator">.</span>size() <span class="operator">=</span><span class="operator">=</span> m_dataLength)
stopRecording();
}
<span class="type">void</span> Engine<span class="operator">::</span>spectrumChanged(<span class="keyword">const</span> FrequencySpectrum <span class="operator">&</span>spectrum)
{
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::spectrumChanged"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"pos"</span> <span class="operator"><</span><span class="operator"><</span> m_spectrumPosition;
<span class="keyword">emit</span> spectrumChanged(m_spectrumPosition<span class="operator">,</span> m_spectrumBufferLength<span class="operator">,</span> spectrum);
}
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="comment">// Private functions</span>
<span class="comment">//-----------------------------------------------------------------------------</span>
<span class="type">void</span> Engine<span class="operator">::</span>resetAudioDevices()
{
<span class="keyword">delete</span> m_audioInput;
m_audioInput <span class="operator">=</span> <span class="number">0</span>;
m_audioInputIODevice <span class="operator">=</span> <span class="number">0</span>;
setRecordPosition(<span class="number">0</span>);
<span class="keyword">delete</span> m_audioOutput;
m_audioOutput <span class="operator">=</span> <span class="number">0</span>;
setPlayPosition(<span class="number">0</span>);
m_spectrumPosition <span class="operator">=</span> <span class="number">0</span>;
setLevel(<span class="number">0.0</span><span class="operator">,</span> <span class="number">0.0</span><span class="operator">,</span> <span class="number">0</span>);
}
<span class="type">void</span> Engine<span class="operator">::</span><a href="qtextstream.html#reset">reset</a>()
{
stopRecording();
stopPlayback();
setState(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>AudioInput<span class="operator">,</span> <span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>StoppedState);
setFormat(<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span>());
m_generateTone <span class="operator">=</span> <span class="keyword">false</span>;
<span class="keyword">delete</span> m_file;
m_file <span class="operator">=</span> <span class="number">0</span>;
<span class="keyword">delete</span> m_analysisFile;
m_analysisFile <span class="operator">=</span> <span class="number">0</span>;
m_buffer<span class="operator">.</span>clear();
m_bufferPosition <span class="operator">=</span> <span class="number">0</span>;
m_bufferLength <span class="operator">=</span> <span class="number">0</span>;
m_dataLength <span class="operator">=</span> <span class="number">0</span>;
<span class="keyword">emit</span> dataLengthChanged(<span class="number">0</span>);
resetAudioDevices();
}
<span class="type">bool</span> Engine<span class="operator">::</span>initialize()
{
<span class="type">bool</span> result <span class="operator">=</span> <span class="keyword">false</span>;
<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> format <span class="operator">=</span> m_format;
<span class="keyword">if</span> (selectFormat()) {
<span class="keyword">if</span> (m_format <span class="operator">!</span><span class="operator">=</span> format) {
resetAudioDevices();
<span class="keyword">if</span> (m_file) {
<span class="keyword">emit</span> bufferLengthChanged(bufferLength());
<span class="keyword">emit</span> dataLengthChanged(dataLength());
<span class="keyword">emit</span> bufferChanged(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> m_buffer);
setRecordPosition(bufferLength());
result <span class="operator">=</span> <span class="keyword">true</span>;
} <span class="keyword">else</span> {
m_bufferLength <span class="operator">=</span> audioLength(m_format<span class="operator">,</span> BufferDurationUs);
m_buffer<span class="operator">.</span>resize(m_bufferLength);
m_buffer<span class="operator">.</span>fill(<span class="number">0</span>);
<span class="keyword">emit</span> bufferLengthChanged(bufferLength());
<span class="keyword">if</span> (m_generateTone) {
<span class="keyword">if</span> (<span class="number">0</span> <span class="operator">=</span><span class="operator">=</span> m_tone<span class="operator">.</span>endFreq) {
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> nyquist <span class="operator">=</span> nyquistFrequency(m_format);
m_tone<span class="operator">.</span>endFreq <span class="operator">=</span> <a href="qtglobal.html#qMin">qMin</a>(<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>(SpectrumHighFreq)<span class="operator">,</span> nyquist);
}
<span class="comment">// Call function defined in utils.h, at global scope</span>
<span class="operator">::</span>generateTone(m_tone<span class="operator">,</span> m_format<span class="operator">,</span> m_buffer);
m_dataLength <span class="operator">=</span> m_bufferLength;
<span class="keyword">emit</span> dataLengthChanged(dataLength());
<span class="keyword">emit</span> bufferChanged(<span class="number">0</span><span class="operator">,</span> m_dataLength<span class="operator">,</span> m_buffer);
setRecordPosition(m_bufferLength);
result <span class="operator">=</span> <span class="keyword">true</span>;
} <span class="keyword">else</span> {
<span class="keyword">emit</span> bufferChanged(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> m_buffer);
m_audioInput <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaudioinput.html">QAudioInput</a></span>(m_audioInputDevice<span class="operator">,</span> m_format<span class="operator">,</span> <span class="keyword">this</span>);
m_audioInput<span class="operator">-</span><span class="operator">></span>setNotifyInterval(NotifyIntervalMs);
result <span class="operator">=</span> <span class="keyword">true</span>;
}
}
m_audioOutput <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qaudiooutput.html">QAudioOutput</a></span>(m_audioOutputDevice<span class="operator">,</span> m_format<span class="operator">,</span> <span class="keyword">this</span>);
m_audioOutput<span class="operator">-</span><span class="operator">></span>setNotifyInterval(NotifyIntervalMs);
}
} <span class="keyword">else</span> {
<span class="keyword">if</span> (m_file)
<span class="keyword">emit</span> errorMessage(tr(<span class="string">"Audio format not supported"</span>)<span class="operator">,</span>
formatToString(m_format));
<span class="keyword">else</span> <span class="keyword">if</span> (m_generateTone)
<span class="keyword">emit</span> errorMessage(tr(<span class="string">"No suitable format found"</span>)<span class="operator">,</span> <span class="string">""</span>);
<span class="keyword">else</span>
<span class="keyword">emit</span> errorMessage(tr(<span class="string">"No common input / output format found"</span>)<span class="operator">,</span> <span class="string">""</span>);
}
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::initialize"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"m_bufferLength"</span> <span class="operator"><</span><span class="operator"><</span> m_bufferLength;
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::initialize"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"m_dataLength"</span> <span class="operator"><</span><span class="operator"><</span> m_dataLength;
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::initialize"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"format"</span> <span class="operator"><</span><span class="operator"><</span> m_format;
<span class="keyword">return</span> result;
}
<span class="type">bool</span> Engine<span class="operator">::</span>selectFormat()
{
<span class="type">bool</span> foundSupportedFormat <span class="operator">=</span> <span class="keyword">false</span>;
<span class="keyword">if</span> (m_file <span class="operator">|</span><span class="operator">|</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span>() <span class="operator">!</span><span class="operator">=</span> m_format) {
<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> format <span class="operator">=</span> m_format;
<span class="keyword">if</span> (m_file)
<span class="comment">// Header is read from the WAV file; just need to check whether</span>
<span class="comment">// it is supported by the audio output device</span>
format <span class="operator">=</span> m_file<span class="operator">-</span><span class="operator">></span>fileFormat();
<span class="keyword">if</span> (m_audioOutputDevice<span class="operator">.</span>isFormatSupported(format)) {
setFormat(format);
foundSupportedFormat <span class="operator">=</span> <span class="keyword">true</span>;
}
} <span class="keyword">else</span> {
<span class="type"><a href="qlist.html">QList</a></span><span class="operator"><</span><span class="type">int</span><span class="operator">></span> frequenciesList;
<span class="preprocessor">#ifdef Q_OS_WIN</span>
<span class="comment">// The Windows audio backend does not correctly report format support</span>
<span class="comment">// (see QTBUG-9100). Furthermore, although the audio subsystem captures</span>
<span class="comment">// at 11025Hz, the resulting audio is corrupted.</span>
frequenciesList <span class="operator">+</span><span class="operator">=</span> <span class="number">8000</span>;
<span class="preprocessor">#endif</span>
<span class="keyword">if</span> (<span class="operator">!</span>m_generateTone)
frequenciesList <span class="operator">+</span><span class="operator">=</span> m_audioInputDevice<span class="operator">.</span>supportedFrequencies();
frequenciesList <span class="operator">+</span><span class="operator">=</span> m_audioOutputDevice<span class="operator">.</span>supportedFrequencies();
frequenciesList <span class="operator">=</span> frequenciesList<span class="operator">.</span>toSet()<span class="operator">.</span>toList(); <span class="comment">// remove duplicates</span>
<a href="qtalgorithms.html#qSort">qSort</a>(frequenciesList);
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::initialize frequenciesList"</span> <span class="operator"><</span><span class="operator"><</span> frequenciesList;
<span class="type"><a href="qlist.html">QList</a></span><span class="operator"><</span><span class="type">int</span><span class="operator">></span> channelsList;
channelsList <span class="operator">+</span><span class="operator">=</span> m_audioInputDevice<span class="operator">.</span>supportedChannels();
channelsList <span class="operator">+</span><span class="operator">=</span> m_audioOutputDevice<span class="operator">.</span>supportedChannels();
channelsList <span class="operator">=</span> channelsList<span class="operator">.</span>toSet()<span class="operator">.</span>toList();
<a href="qtalgorithms.html#qSort">qSort</a>(channelsList);
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::initialize channelsList"</span> <span class="operator"><</span><span class="operator"><</span> channelsList;
<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span> format;
format<span class="operator">.</span>setByteOrder(<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>LittleEndian);
format<span class="operator">.</span>setCodec(<span class="string">"audio/pcm"</span>);
format<span class="operator">.</span>setSampleSize(<span class="number">16</span>);
format<span class="operator">.</span>setSampleType(<span class="type"><a href="qaudioformat.html">QAudioFormat</a></span><span class="operator">::</span>SignedInt);
<span class="type">int</span> frequency<span class="operator">,</span> channels;
foreach (frequency<span class="operator">,</span> frequenciesList) {
<span class="keyword">if</span> (foundSupportedFormat)
<span class="keyword">break</span>;
format<span class="operator">.</span>setFrequency(frequency);
foreach (channels<span class="operator">,</span> channelsList) {
format<span class="operator">.</span>setChannels(channels);
<span class="keyword">const</span> <span class="type">bool</span> inputSupport <span class="operator">=</span> m_generateTone <span class="operator">|</span><span class="operator">|</span>
m_audioInputDevice<span class="operator">.</span>isFormatSupported(format);
<span class="keyword">const</span> <span class="type">bool</span> outputSupport <span class="operator">=</span> m_audioOutputDevice<span class="operator">.</span>isFormatSupported(format);
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::initialize checking "</span> <span class="operator"><</span><span class="operator"><</span> format
<span class="operator"><</span><span class="operator"><</span> <span class="string">"input"</span> <span class="operator"><</span><span class="operator"><</span> inputSupport
<span class="operator"><</span><span class="operator"><</span> <span class="string">"output"</span> <span class="operator"><</span><span class="operator"><</span> outputSupport;
<span class="keyword">if</span> (inputSupport <span class="operator">&</span><span class="operator">&</span> outputSupport) {
foundSupportedFormat <span class="operator">=</span> <span class="keyword">true</span>;
<span class="keyword">break</span>;
}
}
}
<span class="keyword">if</span> (<span class="operator">!</span>foundSupportedFormat)
format <span class="operator">=</span> <span class="type"><a href="qaudioformat.html">QAudioFormat</a></span>();
setFormat(format);
}
<span class="keyword">return</span> foundSupportedFormat;
}
<span class="type">void</span> Engine<span class="operator">::</span>stopRecording()
{
<span class="keyword">if</span> (m_audioInput) {
m_audioInput<span class="operator">-</span><span class="operator">></span>stop();
<span class="type"><a href="qcoreapplication.html">QCoreApplication</a></span><span class="operator">::</span>instance()<span class="operator">-</span><span class="operator">></span>processEvents();
m_audioInput<span class="operator">-</span><span class="operator">></span>disconnect();
}
m_audioInputIODevice <span class="operator">=</span> <span class="number">0</span>;
<span class="preprocessor">#ifdef DUMP_AUDIO</span>
dumpData();
<span class="preprocessor">#endif</span>
}
<span class="type">void</span> Engine<span class="operator">::</span>stopPlayback()
{
<span class="keyword">if</span> (m_audioOutput) {
m_audioOutput<span class="operator">-</span><span class="operator">></span>stop();
<span class="type"><a href="qcoreapplication.html">QCoreApplication</a></span><span class="operator">::</span>instance()<span class="operator">-</span><span class="operator">></span>processEvents();
m_audioOutput<span class="operator">-</span><span class="operator">></span>disconnect();
setPlayPosition(<span class="number">0</span>);
}
}
<span class="type">void</span> Engine<span class="operator">::</span>setState(<span class="type"><a href="qaudio.html">QAudio</a></span><span class="operator">::</span>State state)
{
<span class="keyword">const</span> <span class="type">bool</span> changed <span class="operator">=</span> (m_state <span class="operator">!</span><span class="operator">=</span> state);
m_state <span class="operator">=</span> state;
<span class="keyword">if</span> (changed)
<span class="keyword">emit</span> stateChanged(m_mode<span class="operator">,</span> m_state);
}
<span class="type">void</span> Engine<span class="operator">::</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="keyword">const</span> <span class="type">bool</span> changed <span class="operator">=</span> (m_mode <span class="operator">!</span><span class="operator">=</span> mode <span class="operator">|</span><span class="operator">|</span> m_state <span class="operator">!</span><span class="operator">=</span> state);
m_mode <span class="operator">=</span> mode;
m_state <span class="operator">=</span> state;
<span class="keyword">if</span> (changed)
<span class="keyword">emit</span> stateChanged(m_mode<span class="operator">,</span> m_state);
}
<span class="type">void</span> Engine<span class="operator">::</span>setRecordPosition(<span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> position<span class="operator">,</span> <span class="type">bool</span> forceEmit)
{
<span class="keyword">const</span> <span class="type">bool</span> changed <span class="operator">=</span> (m_recordPosition <span class="operator">!</span><span class="operator">=</span> position);
m_recordPosition <span class="operator">=</span> position;
<span class="keyword">if</span> (changed <span class="operator">|</span><span class="operator">|</span> forceEmit)
<span class="keyword">emit</span> recordPositionChanged(m_recordPosition);
}
<span class="type">void</span> Engine<span class="operator">::</span>setPlayPosition(<span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> position<span class="operator">,</span> <span class="type">bool</span> forceEmit)
{
<span class="keyword">const</span> <span class="type">bool</span> changed <span class="operator">=</span> (m_playPosition <span class="operator">!</span><span class="operator">=</span> position);
m_playPosition <span class="operator">=</span> position;
<span class="keyword">if</span> (changed <span class="operator">|</span><span class="operator">|</span> forceEmit)
<span class="keyword">emit</span> playPositionChanged(m_playPosition);
}
<span class="type">void</span> Engine<span class="operator">::</span>calculateLevel(<span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> position<span class="operator">,</span> <span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> length)
{
<span class="preprocessor">#ifdef DISABLE_LEVEL</span>
Q_UNUSED(position)
Q_UNUSED(length)
<span class="preprocessor">#else</span>
Q_ASSERT(position <span class="operator">+</span> length <span class="operator"><</span><span class="operator">=</span> m_bufferPosition <span class="operator">+</span> m_dataLength);
<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> peakLevel <span class="operator">=</span> <span class="number">0.0</span>;
<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> sum <span class="operator">=</span> <span class="number">0.0</span>;
<span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span>ptr <span class="operator">=</span> m_buffer<span class="operator">.</span>constData() <span class="operator">+</span> position <span class="operator">-</span> m_bufferPosition;
<span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span><span class="keyword">const</span> end <span class="operator">=</span> ptr <span class="operator">+</span> length;
<span class="keyword">while</span> (ptr <span class="operator"><</span> end) {
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint16-typedef">qint16</a></span> value <span class="operator">=</span> <span class="operator">*</span><span class="keyword">reinterpret_cast</span><span class="operator"><</span><span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint16-typedef">qint16</a></span><span class="operator">*</span><span class="operator">></span>(ptr);
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> fracValue <span class="operator">=</span> pcmToReal(value);
peakLevel <span class="operator">=</span> <a href="qtglobal.html#qMax">qMax</a>(peakLevel<span class="operator">,</span> fracValue);
sum <span class="operator">+</span><span class="operator">=</span> fracValue <span class="operator">*</span> fracValue;
ptr <span class="operator">+</span><span class="operator">=</span> <span class="number">2</span>;
}
<span class="keyword">const</span> <span class="type">int</span> numSamples <span class="operator">=</span> length <span class="operator">/</span> <span class="number">2</span>;
<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> rmsLevel <span class="operator">=</span> sqrt(sum <span class="operator">/</span> numSamples);
rmsLevel <span class="operator">=</span> <a href="qtglobal.html#qMax">qMax</a>(<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">0.0</span>)<span class="operator">,</span> rmsLevel);
rmsLevel <span class="operator">=</span> <a href="qtglobal.html#qMin">qMin</a>(<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">1.0</span>)<span class="operator">,</span> rmsLevel);
setLevel(rmsLevel<span class="operator">,</span> peakLevel<span class="operator">,</span> numSamples);
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::calculateLevel"</span> <span class="operator"><</span><span class="operator"><</span> <span class="string">"pos"</span> <span class="operator"><</span><span class="operator"><</span> position <span class="operator"><</span><span class="operator"><</span> <span class="string">"len"</span> <span class="operator"><</span><span class="operator"><</span> length
<span class="operator"><</span><span class="operator"><</span> <span class="string">"rms"</span> <span class="operator"><</span><span class="operator"><</span> rmsLevel <span class="operator"><</span><span class="operator"><</span> <span class="string">"peak"</span> <span class="operator"><</span><span class="operator"><</span> peakLevel;
<span class="preprocessor">#endif</span>
}
<span class="type">void</span> Engine<span class="operator">::</span>calculateSpectrum(<span class="type"><a href="qtglobal.html#qint64-typedef">qint64</a></span> position)
{
<span class="preprocessor">#ifdef DISABLE_SPECTRUM</span>
Q_UNUSED(position)
<span class="preprocessor">#else</span>
Q_ASSERT(position <span class="operator">+</span> m_spectrumBufferLength <span class="operator"><</span><span class="operator">=</span> m_bufferPosition <span class="operator">+</span> m_dataLength);
Q_ASSERT(<span class="number">0</span> <span class="operator">=</span><span class="operator">=</span> m_spectrumBufferLength <span class="operator">%</span> <span class="number">2</span>); <span class="comment">// constraint of FFT algorithm</span>
<span class="comment">// QThread::currentThread is marked 'for internal use only', but</span>
<span class="comment">// we're only using it for debug output here, so it's probably OK :)</span>
ENGINE_DEBUG <span class="operator"><</span><span class="operator"><</span> <span class="string">"Engine::calculateSpectrum"</span> <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="qthread.html">QThread</a></span><span class="operator">::</span>currentThread()
<span class="operator"><</span><span class="operator"><</span> <span class="string">"count"</span> <span class="operator"><</span><span class="operator"><</span> m_count <span class="operator"><</span><span class="operator"><</span> <span class="string">"pos"</span> <span class="operator"><</span><span class="operator"><</span> position <span class="operator"><</span><span class="operator"><</span> <span class="string">"len"</span> <span class="operator"><</span><span class="operator"><</span> m_spectrumBufferLength
<span class="operator"><</span><span class="operator"><</span> <span class="string">"spectrumAnalyser.isReady"</span> <span class="operator"><</span><span class="operator"><</span> m_spectrumAnalyser<span class="operator">.</span>isReady();
<span class="keyword">if</span>(m_spectrumAnalyser<span class="operator">.</span>isReady()) {
m_spectrumBuffer <span class="operator">=</span> <span class="type"><a href="qbytearray.html">QByteArray</a></span><span class="operator">::</span>fromRawData(m_buffer<span class="operator">.</span>constData() <span class="operator">+</span> position <span class="operator">-</span> m_bufferPosition<span class="operator">,</span>
m_spectrumBufferLength);
m_spectrumPosition <span class="operator">=</span> position;
m_spectrumAnalyser<span class="operator">.</span>calculate(m_spectrumBuffer<span class="operator">,</span> m_format);
}
<span class="preprocessor">#endif</span>
}
<span class="type">void</span> Engine<span class="operator">::</span>setFormat(<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="type">bool</span> changed <span class="operator">=</span> (format <span class="operator">!</span><span class="operator">=</span> m_format);
m_format <span class="operator">=</span> format;
m_levelBufferLength <span class="operator">=</span> audioLength(m_format<span class="operator">,</span> LevelWindowUs);
m_spectrumBufferLength <span class="operator">=</span> SpectrumLengthSamples <span class="operator">*</span>
(m_format<span class="operator">.</span>sampleSize() <span class="operator">/</span> <span class="number">8</span>) <span class="operator">*</span> m_format<span class="operator">.</span>channels();
<span class="keyword">if</span> (changed)
<span class="keyword">emit</span> formatChanged(m_format);
}
<span class="type">void</span> Engine<span class="operator">::</span>setLevel(<span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> rmsLevel<span class="operator">,</span> <span class="type"><a href="qtglobal.html#qreal-typedef">qreal</a></span> peakLevel<span class="operator">,</span> <span class="type">int</span> numSamples)
{
m_rmsLevel <span class="operator">=</span> rmsLevel;
m_peakLevel <span class="operator">=</span> peakLevel;
<span class="keyword">emit</span> levelChanged(m_rmsLevel<span class="operator">,</span> m_peakLevel<span class="operator">,</span> numSamples);
}
<span class="preprocessor">#ifdef DUMP_DATA</span>
<span class="type">void</span> Engine<span class="operator">::</span>createOutputDir()
{
m_outputDir<span class="operator">.</span>setPath(<span class="string">"output"</span>);
<span class="comment">// Ensure output directory exists and is empty</span>
<span class="keyword">if</span> (m_outputDir<span class="operator">.</span>exists()) {
<span class="keyword">const</span> <span class="type"><a href="qstringlist.html">QStringList</a></span> files <span class="operator">=</span> m_outputDir<span class="operator">.</span>entryList(<span class="type"><a href="qdir.html">QDir</a></span><span class="operator">::</span>Files);
<span class="type"><a href="qstring.html">QString</a></span> file;
foreach (file<span class="operator">,</span> files)
m_outputDir<span class="operator">.</span>remove(file);
} <span class="keyword">else</span> {
<span class="type"><a href="qdir.html">QDir</a></span><span class="operator">::</span>current()<span class="operator">.</span>mkdir(<span class="string">"output"</span>);
}
}
<span class="preprocessor">#endif // DUMP_DATA</span>
<span class="preprocessor">#ifdef DUMP_AUDIO</span>
<span class="type">void</span> Engine<span class="operator">::</span>dumpData()
{
<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> txtFileName <span class="operator">=</span> m_outputDir<span class="operator">.</span>filePath(<span class="string">"data.txt"</span>);
<span class="type"><a href="qfile.html">QFile</a></span> txtFile(txtFileName);
txtFile<span class="operator">.</span>open(<span class="type"><a href="qfile.html">QFile</a></span><span class="operator">::</span>WriteOnly <span class="operator">|</span> <span class="type"><a href="qfile.html">QFile</a></span><span class="operator">::</span>Text);
<span class="type"><a href="qtextstream.html">QTextStream</a></span> stream(<span class="operator">&</span>txtFile);
<span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint16-typedef">qint16</a></span> <span class="operator">*</span>ptr <span class="operator">=</span> <span class="keyword">reinterpret_cast</span><span class="operator"><</span><span class="keyword">const</span> <span class="type"><a href="qtglobal.html#qint16-typedef">qint16</a></span><span class="operator">*</span><span class="operator">></span>(m_buffer<span class="operator">.</span>constData());
<span class="keyword">const</span> <span class="type">int</span> numSamples <span class="operator">=</span> m_dataLength <span class="operator">/</span> (<span class="number">2</span> <span class="operator">*</span> m_format<span class="operator">.</span>channels());
<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>numSamples; <span class="operator">+</span><span class="operator">+</span>i) {
stream <span class="operator"><</span><span class="operator"><</span> i <span class="operator"><</span><span class="operator"><</span> <span class="string">"\t"</span> <span class="operator"><</span><span class="operator"><</span> <span class="operator">*</span>ptr <span class="operator"><</span><span class="operator"><</span> <span class="string">"\n"</span>;
ptr <span class="operator">+</span><span class="operator">=</span> m_format<span class="operator">.</span>channels();
}
<span class="keyword">const</span> <span class="type"><a href="qstring.html">QString</a></span> pcmFileName <span class="operator">=</span> m_outputDir<span class="operator">.</span>filePath(<span class="string">"data.pcm"</span>);
<span class="type"><a href="qfile.html">QFile</a></span> pcmFile(pcmFileName);
pcmFile<span class="operator">.</span>open(<span class="type"><a href="qfile.html">QFile</a></span><span class="operator">::</span>WriteOnly);
pcmFile<span class="operator">.</span>write(m_buffer<span class="operator">.</span>constData()<span class="operator">,</span> m_dataLength);
}
<span class="preprocessor">#endif // DUMP_AUDIO</span></pre>
</div>
<!-- @@@demos/spectrum/app/engine.cpp -->
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