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50
51#ifndef UTILS_H
52#define UTILS_H
53
54#include <QtCore/qglobal.h>
55#include <QDebug>
56
57QT_FORWARD_DECLARE_CLASS(QAudioFormat)
58
59//-----------------------------------------------------------------------------
60// Miscellaneous utility functions
61//-----------------------------------------------------------------------------
62
63qint64 audioDuration(const QAudioFormat &format, qint64 bytes);
64qint64 audioLength(const QAudioFormat &format, qint64 microSeconds);
65
66QString formatToString(const QAudioFormat &format);
67
68qreal nyquistFrequency(const QAudioFormat &format);
69
70// Scale PCM value to [-1.0, 1.0]
71qreal pcmToReal(qint16 pcm);
72
73// Scale real value in [-1.0, 1.0] to PCM
74qint16 realToPcm(qreal real);
75
76// Check whether the audio format is PCM
77bool isPCM(const QAudioFormat &format);
78
79// Check whether the audio format is signed, little-endian, 16-bit PCM
80bool isPCMS16LE(const QAudioFormat &format);
81
82// Compile-time calculation of powers of two
83
84template<int N> class PowerOfTwo
85{ public: static const int Result = PowerOfTwo<N-1>::Result * 2; };
86
87template<> class PowerOfTwo<0>
88{ public: static const int Result = 1; };
89
90
91//-----------------------------------------------------------------------------
92// Debug output
93//-----------------------------------------------------------------------------
94
95class NullDebug
96{
97public:
98 template <typename T>
99 NullDebug& operator<<(const T&) { return *this; }
100};
101
102inline NullDebug nullDebug() { return NullDebug(); }
103
104#ifdef LOG_ENGINE
105# define ENGINE_DEBUG qDebug()
106#else
107# define ENGINE_DEBUG nullDebug()
108#endif
109
110#ifdef LOG_SPECTRUMANALYSER
111# define SPECTRUMANALYSER_DEBUG qDebug()
112#else
113# define SPECTRUMANALYSER_DEBUG nullDebug()
114#endif
115
116#ifdef LOG_WAVEFORM
117# define WAVEFORM_DEBUG qDebug()
118#else
119# define WAVEFORM_DEBUG nullDebug()
120#endif
121
122#endif // UTILS_H
123

source code of qtmultimedia/examples/multimedia/spectrum/app/utils.h