guitartuner.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation (qt-info@nokia.com)
 **
 ** This file is part of the QtDeclarative module 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 Nokia Corporation and its Subsidiary(-ies) 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."
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "guitartuner.h"

 #ifdef Q_OS_SYMBIAN
 #include <SoundDevice.h>
 #endif // Q_OS_SYMBIAN

 #if defined(Q_OS_SYMBIAN) && defined(ORIENTATIONLOCK)
 #include <eikenv.h>
 #include <eikappui.h>
 #include <aknenv.h>
 #include <aknappui.h>
 #endif // Q_OS_SYMBIAN && ORIENTATIONLOCK

 GuitarTuner::GuitarTuner(QWidget *parent) :
     QMainWindow(parent)
 {

     // Set up the QML.
     m_guitarTunerUI = new QDeclarativeView(QUrl("qrc:/src/application.qml"), this);
     setCentralWidget(m_guitarTunerUI);
     m_guitarTunerUI->setResizeMode(QDeclarativeView::SizeRootObjectToView);
     qmlObject = m_guitarTunerUI->rootObject();

     // Init audio output and input.
     initAudioOutput();
     initAudioInput();

     // Connect the quit signal of m_guitarTunerUI
     // into the close slot of this.
     connect(m_guitarTunerUI->engine(), SIGNAL(quit()), SLOT(close()));

     // Connect the signals from qmlObject into proper slots
     // of this and m_voicegenerator.
     connect(qmlObject, SIGNAL(muteStateChanged(bool)),
             SLOT(muteStateChanged(bool)));
     connect(qmlObject, SIGNAL(volumeChanged(qreal)),
             m_voicegenerator, SLOT(setAmplitude(qreal)));
     connect(qmlObject, SIGNAL(volumeChanged(qreal)),
             SLOT(setMaxVolumeLevel(qreal)));

     // Connect the modeChanged signal from qmlObject
     // into modeChanged slot of this class.
     connect(qmlObject, SIGNAL(modeChanged(bool)),
             SLOT(modeChanged(bool)));

     // Connect the microphoneSensitivityChanged signal from
     // m_guitarTunerUI into setCutOffPercentage slot of m_analyzer class.
     connect(qmlObject, SIGNAL(microphoneSensitivityChanged(qreal)),
             m_analyzer, SLOT(setCutOffPercentage(qreal)));

     // Connect the signals from m_analyzer into slots of qmlObject.
     connect(m_analyzer, SIGNAL(lowVoice()),
             qmlObject, SLOT(lowVoice()));
     connect(m_analyzer, SIGNAL(correctFrequency()),
             qmlObject, SLOT(correctFrequencyObtained()));
     connect(m_analyzer, SIGNAL(voiceDifference(QVariant)),
             qmlObject, SLOT(voiceDifferenceChanged(QVariant)));

     // Initialise the MaximumVoiceDifference
     // value of qmlObject with the value obtained from m_analyzer.
     qmlObject->setProperty("maxVoiceDifference",
                            m_analyzer->getMaximumVoiceDifference());

     // Connect the targetFrequencyChanged signal of qmlObject
     // into targetFrequencyChanged slot of this class.
     connect(qmlObject, SIGNAL(targetFrequencyChanged(qreal)),
             SLOT(targetFrequencyChanged(qreal)));

     // Start voice output or input by using the modeChanged function,
     // depending of the current mode.
     modeChanged(qmlObject->property("isInput").toBool());

 }

 /**
   * Inits audio output.
   */
 void GuitarTuner::initAudioOutput()
 {
     // Set up the output format.
     m_format_output.setFrequency(DataFrequencyHzOutput);
     m_format_output.setCodec("audio/pcm");
     m_format_output.setSampleSize(16);
     m_format_output.setChannels(1);
     m_format_output.setByteOrder(QAudioFormat::LittleEndian);
     m_format_output.setSampleType(QAudioFormat::SignedInt);

     // Obtain a default output device, and if the format is not
     // supported, find the nearest format available.
     QAudioDeviceInfo outputDeviceInfo(
                 QAudioDeviceInfo::defaultOutputDevice());
     if (!outputDeviceInfo.isFormatSupported(m_format_output)) {
         m_format_output = outputDeviceInfo.nearestFormat(m_format_output);
     }

     // Create new QAudioOutput and VoiceGenerator instances, and store
     // them in m_audioOutput and m_voicegenerator, respectively.
     m_audioOutput = new QAudioOutput(outputDeviceInfo,
                                      m_format_output, this);
     m_voicegenerator = new VoiceGenerator(m_format_output,
                                           qmlObject->property("frequency").toReal(),
                                           qmlObject->property("volume").toReal(),
                                           this);

     // Connect m_audioOutput stateChanged signal to outputStateChanged.
     connect(m_audioOutput, SIGNAL(stateChanged(QAudio::State)),
             SLOT(outputStateChanged(QAudio::State)));
 }

 /**
   * Inits audio input.
   */
 void GuitarTuner::initAudioInput()
 {
     // Set up the input format.
     m_format_input.setFrequency(DataFrequencyHzInput);
     m_format_input.setCodec("audio/pcm");
     m_format_input.setSampleSize(16);
     m_format_input.setChannels(1);
     m_format_input.setByteOrder(QAudioFormat::LittleEndian);
     m_format_input.setSampleType(QAudioFormat::SignedInt);

     // Obtain a default input device, and if the format is not
     // supported, find the nearest format available.
     QAudioDeviceInfo inputDeviceInfo(
                 QAudioDeviceInfo::defaultInputDevice());
     if (!inputDeviceInfo.isFormatSupported(m_format_input)) {
         m_format_input = inputDeviceInfo.nearestFormat(m_format_input);
     }

     // Create new QAudioInput and VoiceAnalyzer instances, and store
     // them in m_audioInput and m_analyzer, respectively.
     // Remember to set the cut-off percentage for voice analyzer.
     m_audioInput = new QAudioInput(inputDeviceInfo, m_format_input, this);
     m_analyzer = new VoiceAnalyzer(m_format_input, this);
     m_analyzer->setCutOffPercentage(qmlObject->property("sensitivity").toReal());

 }

 /**
   * Receives a mode changed signal.
   */
 void GuitarTuner::modeChanged(bool isInput)
 {

     // If the mode must be changed to input mode:
     if (isInput) {

         // Stop audio output and audio generator.
         m_audioOutput->stop();
         m_voicegenerator->stop();
         // Start the audio analyzer and then the audio input.
         m_analyzer->start(qmlObject->property("frequency").toReal());
         m_audioInput->start(m_analyzer);

     }
     // Else:
     else {

         // Stop audio input and audio analyzer.
         m_audioInput->stop();
         m_analyzer->stop();

         // Set up the audio output.

         // If the current frequency of voice generator
         // is not the same as the target frequency selected in the UI,
         // update voice generator's frequency.
         if (m_voicegenerator->frequency() != qmlObject->property("frequency").toReal()) {
             m_voicegenerator->setFrequency(qmlObject->property("frequency").toReal());
         }

         // Start the voice generator and then the audio output.
         m_voicegenerator->start();
         m_audioOutput->start(m_voicegenerator);
         // Call setMaxVolumeLevel(1) to set the maximum volume louder.
         setMaxVolumeLevel(qmlObject->property("volume").toReal());

         // If the voice is muted, the voice is suspended
         // in the outputStateChanged slot.

     }
 }

 /**
   * Receives a output state changed signal.
   * Suspends the audio output, if the state is ActiveState
   * and the voice is muted.
   */
 void GuitarTuner::outputStateChanged(QAudio::State state)
 {
     if (QAudio::ActiveState == state && qmlObject->property("isMuted").toBool()) {
         // If the voice is muted, suspend the voice.
         m_audioOutput->suspend();
     }
 }

 /**
   * Receives a mute state changed signal.
   * Suspends the audio output or resumes it, depending of the
   * isMuted parameter.
   */
 void GuitarTuner::muteStateChanged(bool isMuted)
 {
     if (isMuted) {
         m_audioOutput->suspend();
     }
     else {
         m_audioOutput->resume();
     }
 }

 /**
   * Receives a target frequency signal.
   */
 void GuitarTuner::targetFrequencyChanged(qreal targetFrequency)
 {
     // If the output mode is active:
     if (!qmlObject->property("isInput").toBool()) {
         // Stop the audio output and voice generator.
         m_audioOutput->stop();
         m_voicegenerator->stop();
         // Set the voice generator's frequency to the target frequency.
         m_voicegenerator->setFrequency(targetFrequency);
         // Start the voice generator and audio output.
         m_voicegenerator->start();
         m_audioOutput->start(m_voicegenerator);
         // Call setMaxVolumeLevel(1) to set the maximum volume louder.
         setMaxVolumeLevel(qmlObject->property("volume").toReal());

         // If the voice is muted, the voice is suspended
         // in the outputStateChanged slot.

     }
     // Else:
     else {

         // Stop the audio input and voice analyzer.
         m_audioInput->stop();
         m_analyzer->stop();
         // Start the voice analyzer with new frequency and audio input.
         m_analyzer->start(targetFrequency);
         m_audioInput->start(m_analyzer);

     }
 }

 /**
   * This method provides a hack to set the maximum volume level in
   * Symbian.
   */
 void GuitarTuner::setMaxVolumeLevel(qreal percent)
 {
     if (percent >= 1.0) {
         percent = 1.0;
     }
     else if (percent <= 0.0) {
         percent = 0.0;
     }
     percent = percent*0.5 + 0.5;
     // Warning! This is a hack, which can break when the QtMobility
     // changes. Use at your own risk.
 #ifdef Q_OS_SYMBIAN
     unsigned int *pointer_to_abstract_audio
             = (unsigned int*)( (unsigned char*)m_audioOutput + 8 );
     unsigned int *dev_sound_wrapper
             = (unsigned int*)(*pointer_to_abstract_audio) + 16;
     unsigned int *temp
             = ((unsigned int*)(*dev_sound_wrapper) + 6);
     CMMFDevSound *dev_sound = (CMMFDevSound*)(*temp);
     dev_sound->SetVolume((unsigned int)
                          (percent*(float)dev_sound->MaxVolume()));
 #endif
 }

 /**
   * A function used to lock the orientation.
   */
 void GuitarTuner::setOrientation(Orientation orientation)
 {
 #ifdef Q_OS_SYMBIAN
     if (orientation != Auto) {
 #if defined(ORIENTATIONLOCK)
         const CAknAppUiBase::TAppUiOrientation uiOrientation =
                 (orientation == LockPortrait)
                     ? CAknAppUi::EAppUiOrientationPortrait
                     : CAknAppUi::EAppUiOrientationLandscape;
         CAknAppUi* appUi = dynamic_cast<CAknAppUi*>
                 (CEikonEnv::Static()->AppUi());
         TRAPD(error,
             if (appUi)
                 appUi->SetOrientationL(uiOrientation);
         );
 #else // ORIENTATIONLOCK
         qWarning(QString("'ORIENTATIONLOCK' needs to be defined on")
                  +QString(" Symbian when locking the orientation."));
 #endif // ORIENTATIONLOCK
     }
 #elif defined(Q_WS_MAEMO_5)
     Qt::WidgetAttribute attribute;
     switch (orientation) {
     case LockPortrait:
         attribute = Qt::WA_Maemo5PortraitOrientation;
         break;
     case LockLandscape:
         attribute = Qt::WA_Maemo5LandscapeOrientation;
         break;
     case Auto:
     default:
         attribute = Qt::WA_Maemo5AutoOrientation;
         break;
     }
     setAttribute(attribute, true);
 #else // Q_OS_SYMBIAN
     Q_UNUSED(orientation);
 #endif // Q_OS_SYMBIAN
 }