audiooutput.h Example File | Qt Multimedia 5.9

Qt 5.9 | Qt Multimedia | Audio Output Example | audiooutput.h Example File

Qt 5.9.9 Reference Documentation

# audiooutput.h Example File

multimedia/audiooutput/audiooutput.h

      /****************************************************************************
      **
      ** Copyright (C) 2017 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the examples of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** BSD License Usage
      ** Alternatively, 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 <QAudioOutput>
      #include <QByteArray>
      #include <QComboBox>
      #include <QIODevice>
      #include <QLabel>
      #include <QMainWindow>
      #include <QObject>
      #include <QPushButton>
      #include <QSlider>
      #include <QTimer>

      class Generator : public QIODevice
      {
          Q_OBJECT

      public:
          Generator(const QAudioFormat &format, qint64 durationUs, int sampleRate, QObject *parent);
          ~Generator();

          void start();
          void stop();

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

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

      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_pushTimer;

          // Owned by layout
          QPushButton *m_modeButton;
          QPushButton *m_suspendResumeButton;
          QComboBox *m_deviceBox;
          QLabel *m_volumeLabel;
          QSlider *m_volumeSlider;

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

          bool m_pullMode;
          QByteArray m_buffer;

      private slots:
          void pushTimerExpired();
          void toggleMode();
          void toggleSuspendResume();
          void deviceChanged(int index);
          void volumeChanged(int);
      };

      #endif // AUDIOOUTPUT_H