utils.h Example File

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  #ifndef UTILS_H
  #define UTILS_H

  #include <QtCore/qglobal.h>
  #include <QDebug>

  QT_FORWARD_DECLARE_CLASS(QAudioFormat)

  //-----------------------------------------------------------------------------
  // Miscellaneous utility functions
  //-----------------------------------------------------------------------------

  qint64 audioDuration(const QAudioFormat &format, qint64 bytes);
  qint64 audioLength(const QAudioFormat &format, qint64 microSeconds);

  QString formatToString(const QAudioFormat &format);

  qreal nyquistFrequency(const QAudioFormat &format);

  // Scale PCM value to [-1.0, 1.0]
  qreal pcmToReal(qint16 pcm);

  // Scale real value in [-1.0, 1.0] to PCM
  qint16 realToPcm(qreal real);

  // Check whether the audio format is PCM
  bool isPCM(const QAudioFormat &format);

  // Check whether the audio format is signed, little-endian, 16-bit PCM
  bool isPCMS16LE(const QAudioFormat &format);

  // Compile-time calculation of powers of two

  template<int N> class PowerOfTwo
  { public: static const int Result = PowerOfTwo<N-1>::Result * 2; };

  template<> class PowerOfTwo<0>
  { public: static const int Result = 1; };

  //-----------------------------------------------------------------------------
  // Debug output
  //-----------------------------------------------------------------------------

  class NullDebug
  {
  public:
      template <typename T>
      NullDebug& operator<<(const T&) { return *this; }
  };

  inline NullDebug nullDebug() { return NullDebug(); }

  #ifdef LOG_ENGINE
  #   define ENGINE_DEBUG qDebug()
  #else
  #   define ENGINE_DEBUG nullDebug()
  #endif

  #ifdef LOG_SPECTRUMANALYSER
  #   define SPECTRUMANALYSER_DEBUG qDebug()
  #else
  #   define SPECTRUMANALYSER_DEBUG nullDebug()
  #endif

  #ifdef LOG_WAVEFORM
  #   define WAVEFORM_DEBUG qDebug()
  #else
  #   define WAVEFORM_DEBUG nullDebug()
  #endif

  #endif // UTILS_H