/****************************************************************************+
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**+
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** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).+
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** All rights reserved.+
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** Contact: Nokia Corporation (qt-info@nokia.com)+
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**+
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** This file is part of the examples of the Qt Toolkit.+
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**+
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** $QT_BEGIN_LICENSE:BSD$+
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** You may use this file under the terms of the BSD license as follows:+
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**+
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** Redistribution and use in source and binary forms, with or without+
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** modification, are permitted provided that the following conditions are met:+
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** - Redistributions of source code must retain the above copyright notice,+
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**   this list of conditions and the following disclaimer.+
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** - Redistributions in binary form must reproduce the above copyright notice,+
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**   this list of conditions and the following disclaimer in the documentation+
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**   and/or other materials provided with the distribution.+
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** - Neither the name of Nokia Corporation and its Subsidiary(-ies) nor the+
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**   names of its contributors may be used to endorse or promote products+
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**   derived from this software without specific prior written permission.+
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**+
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** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"+
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** AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE+
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** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE+
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** ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE+
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** LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR+
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** CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF+
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** SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS+
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** INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN+
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** CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)+
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** ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE+
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** POSSIBILITY OF SUCH DAMAGE.+
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** $QT_END_LICENSE$+
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**+
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*****************************************************************************/+
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+
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#ifndef ENGINE_H+
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#define ENGINE_H+
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+
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#include "spectrum.h"+
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#include "spectrumanalyser.h"+
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#include "wavfile.h"+
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+
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#include <QObject>+
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#include <QByteArray>+
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#include <QBuffer>+
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#include <QVector>+
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#include <QtMultimedia/QAudioDeviceInfo>+
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#include <QtMultimedia/QAudioFormat>+
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+
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#ifdef DUMP_CAPTURED_AUDIO+
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#define DUMP_DATA+
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#endif+
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+
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#ifdef DUMP_SPECTRUM+
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#define DUMP_DATA+
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#endif+
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+
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#ifdef DUMP_DATA+
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#include <QDir>+
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#endif+
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+
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class QAudioInput;+
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class QAudioOutput;+
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class FrequencySpectrum;+
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class QFile;+
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+
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/**+
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 * This class interfaces with the QtMultimedia audio classes, and also with+
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 * the SpectrumAnalyser class.  Its role is to manage the capture and playback+
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 * of audio data, meanwhile performing real-time analysis of the audio level+
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 * and frequency spectrum.+
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 */+
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class Engine : public QObject {+
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    Q_OBJECT+
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public:+
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    Engine(QObject *parent = 0);+
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    ~Engine();+
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+
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    const QList<QAudioDeviceInfo>& availableAudioInputDevices() const+
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                                    { return m_availableAudioInputDevices; }+
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+
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    const QList<QAudioDeviceInfo>& availableAudioOutputDevices() const+
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                                    { return m_availableAudioOutputDevices; }+
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+
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    QAudio::Mode mode() const       { return m_mode; }+
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    QAudio::State state() const     { return m_state; }+
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+
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    /**+
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     * \return Reference to internal audio buffer+
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     * \note This reference is valid for the lifetime of the Engine+
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     */+
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    const QByteArray& buffer() const    { return m_buffer; }+
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+
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    /**+
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     * \return Current audio format+
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     * \note May be QAudioFormat() if engine is not initialized+
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     */+
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    const QAudioFormat& format() const  { return m_format; }+
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+
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    /**+
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     * Stop any ongoing recording or playback, and reset to ground state.+
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     */+
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    void reset();+
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+
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    /**+
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     * Load data from WAV file+
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     */+
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    bool loadFile(const QString &fileName);+
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+
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    /**+
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     * Generate tone+
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     */+
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    bool generateTone(const Tone &tone);+
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+
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    /**+
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     * Generate tone+
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     */+
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    bool generateSweptTone(qreal amplitude);+
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+
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    /**+
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     * Initialize for recording+
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     */+
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    bool initializeRecord();+
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+
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    /**+
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     * Position of the audio input device.+
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     * \return Position in microseconds.+
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     */+
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    qint64 recordPosition() const   { return m_recordPosition; }+
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+
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    /**+
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     * RMS level of the most recently processed set of audio samples.+
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     * \return Level in range (0.0, 1.0)+
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     */+
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    qreal rmsLevel() const          { return m_rmsLevel; }+
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+
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    /**+
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     * Peak level of the most recently processed set of audio samples.+
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     * \return Level in range (0.0, 1.0)+
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     */+
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    qreal peakLevel() const         { return m_peakLevel; }+
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+
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    /**+
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     * Position of the audio output device.+
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     * \return Position in microseconds.+
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     */+
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    qint64 playPosition() const     { return m_playPosition; }+
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+
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    /**+
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     * Length of the internal engine buffer.+
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     * \return Buffer length in microseconds.+
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     */+
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    qint64 bufferDuration() const;+
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+
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    /**+
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     * Amount of data held in the buffer.+
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     * \return Data duration in microseconds.+
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     */+
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    qint64 dataDuration() const;+
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+
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    /**+
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     * Returns the size of the underlying audio buffer in bytes.+
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     * This should be an approximation of the capture latency.+
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     */+
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    qint64 audioBufferLength() const;+
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+
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    /**+
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     * Set window function applied to audio data before spectral analysis.+
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     */+
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    void setWindowFunction(WindowFunction type);+
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+
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public slots:+
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    void startRecording();+
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    void startPlayback();+
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    void suspend();+
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    void setAudioInputDevice(const QAudioDeviceInfo &device);+
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    void setAudioOutputDevice(const QAudioDeviceInfo &device);+
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+
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signals:+
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    void stateChanged(QAudio::Mode mode, QAudio::State state);+
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+
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    /**+
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     * Informational message for non-modal display+
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     */+
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    void infoMessage(const QString &message, int durationMs);+
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+
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    /**+
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     * Error message for modal display+
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     */+
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    void errorMessage(const QString &heading, const QString &detail);+
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+
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    /**+
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     * Format of audio data has changed+
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     */+
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    void formatChanged(const QAudioFormat &format);+
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+
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    /**+
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     * Length of buffer has changed.+
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     * \param duration Duration in microseconds+
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     */+
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    void bufferDurationChanged(qint64 duration);+
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+
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    /**+
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     * Amount of data in buffer has changed.+
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     * \param duration Duration of data in microseconds+
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     */+
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    void dataDurationChanged(qint64 duration);+
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+
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    /**+
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     * Position of the audio input device has changed.+
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     * \param position Position in microseconds+
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     */+
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    void recordPositionChanged(qint64 position);+
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+
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    /**+
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     * Position of the audio output device has changed.+
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     * \param position Position in microseconds+
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     */+
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    void playPositionChanged(qint64 position);+
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+
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    /**+
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     * Level changed+
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     * \param rmsLevel RMS level in range 0.0 - 1.0+
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     * \param peakLevel Peak level in range 0.0 - 1.0+
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     * \param numSamples Number of audio samples analysed+
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     */+
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    void levelChanged(qreal rmsLevel, qreal peakLevel, int numSamples);+
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+
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    /**+
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     * Spectrum has changed.+
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     * \param position Position of start of window in microseconds+
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     * \param length   Length of window in microseconds+
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     * \param spectrum Resulting frequency spectrum+
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     */+
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    void spectrumChanged(qint64 position, qint64 length, const FrequencySpectrum &spectrum);+
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+
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private slots:+
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    void audioNotify();+
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    void audioStateChanged(QAudio::State state);+
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    void audioDataReady();+
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    void spectrumChanged(const FrequencySpectrum &spectrum);+
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+
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private:+
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    bool initialize();+
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    bool selectFormat();+
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    void stopRecording();+
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    void stopPlayback();+
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    void setState(QAudio::State state);+
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    void setState(QAudio::Mode mode, QAudio::State state);+
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    void setFormat(const QAudioFormat &format);+
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    void setRecordPosition(qint64 position, bool forceEmit = false);+
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    void setPlayPosition(qint64 position, bool forceEmit = false);+
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    void calculateLevel(qint64 position, qint64 length);+
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    void calculateSpectrum(qint64 position);+
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    void setLevel(qreal rmsLevel, qreal peakLevel, int numSamples);+
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+
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#ifdef DUMP_DATA+
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    void createOutputDir();+
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    QString outputPath() const { return m_outputDir.path(); }+
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#endif+
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+
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#ifdef DUMP_CAPTURED_AUDIO+
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    void dumpData();+
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#endif+
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+
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private:+
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    QAudio::Mode        m_mode;+
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    QAudio::State       m_state;+
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+
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    bool                m_generateTone;+
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    SweptTone           m_tone;+
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+
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    QFile*              m_file;+
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    WavFile             m_wavFile;+
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+
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    QAudioFormat        m_format;+
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+
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    const QList<QAudioDeviceInfo> m_availableAudioInputDevices;+
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    QAudioDeviceInfo    m_audioInputDevice;+
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    QAudioInput*        m_audioInput;+
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    QIODevice*          m_audioInputIODevice;+
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    qint64              m_recordPosition;+
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+
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    const QList<QAudioDeviceInfo> m_availableAudioOutputDevices;+
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    QAudioDeviceInfo    m_audioOutputDevice;+
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    QAudioOutput*       m_audioOutput;+
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    qint64              m_playPosition;+
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    QBuffer             m_audioOutputIODevice;+
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+
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    QByteArray          m_buffer;+
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    qint64              m_dataLength;+
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+
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    qreal               m_rmsLevel;+
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    qreal               m_peakLevel;+
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+
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    int                 m_spectrumLengthBytes;+
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    QByteArray          m_spectrumBuffer;+
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    SpectrumAnalyser    m_spectrumAnalyser;+
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    qint64              m_spectrumPosition;+
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+
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    int                 m_count;+
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+
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#ifdef DUMP_DATA+
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    QDir                m_outputDir;+
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#endif+
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+
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};+
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+
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#endif // ENGINE_H+
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