audiooutput.h Example File

/****************************************************************************
**
** 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."
**
** $QT_END_LICENSE$
**
****************************************************************************/
#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