Qt 4.8: audiooutput.h Example File (multimedia/audiooutput/audiooutput.h)

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# audiooutput.h Example File

multimedia/audiooutput/audiooutput.h

     /****************************************************************************
     **
     ** 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:
     **
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     ** modification, are permitted provided that the following conditions are
     ** met:
     **   * Redistributions of source code must retain the above copyright
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     #ifndef AUDIOOUTPUT_H
     #define AUDIOOUTPUT_H

     #include <math.h>

     #include <QObject>
     #include <QMainWindow>
     #include <QIODevice>
     #include <QTimer>
     #include <QPushButton>
     #include <QComboBox>
     #include <QByteArray>

     #include <QAudioOutput>

     class Generator : public QIODevice
     {
         Q_OBJECT
     public:
         Generator(const QAudioFormat &format, qint64 durationUs, int frequency, QObject *parent);
         ~Generator();

         void start();
         void stop();

         qint64 readData(char *data, qint64 maxlen);
         qint64 writeData(const char *data, qint64 len);
         qint64 bytesAvailable() const;

     private:
         void generateData(const QAudioFormat &format, qint64 durationUs, int frequency);

     private:
         qint64 m_pos;
         QByteArray m_buffer;
     };

     class AudioTest : public QMainWindow
     {
         Q_OBJECT
     public:
         AudioTest();
         ~AudioTest();

     private:
         void initializeWindow();
         void initializeAudio();
         void createAudioOutput();

     private:
         QTimer*          m_pullTimer;

         // Owned by layout
         QPushButton*     m_modeButton;
         QPushButton*     m_suspendResumeButton;
         QComboBox*       m_deviceBox;

         QAudioDeviceInfo m_device;
         Generator*       m_generator;
         QAudioOutput*    m_audioOutput;
         QIODevice*       m_output; // not owned
         QAudioFormat     m_format;

         bool             m_pullMode;
         QByteArray       m_buffer;

         static const QString PushModeLabel;
         static const QString PullModeLabel;
         static const QString SuspendLabel;
         static const QString ResumeLabel;

     private slots:
         void notified();
         void pullTimerExpired();
         void toggleMode();
         void toggleSuspendResume();
         void stateChanged(QAudio::State state);
         void deviceChanged(int index);
     };

     #endif