Qt 5.8 | Qt Multimedia | Audio Output Example | audiooutput.h Example File

Qt 5.8.0 Reference Documentation

# audiooutput.h Example File

multimedia/audiooutput/audiooutput.h

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

      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