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50
51#ifndef SPECTRUM_H
52#define SPECTRUM_H
53
54#include <qglobal.h>
55#include "utils.h"
56#include "fftreal_wrapper.h" // For FFTLengthPowerOfTwo
57
58//-----------------------------------------------------------------------------
59// Constants
60//-----------------------------------------------------------------------------
61
62// Number of audio samples used to calculate the frequency spectrum
63const int SpectrumLengthSamples = PowerOfTwo<FFTLengthPowerOfTwo>::Result;
64
65// Number of bands in the frequency spectrum
66const int SpectrumNumBands = 10;
67
68// Lower bound of first band in the spectrum
69const qreal SpectrumLowFreq = 0.0; // Hz
70
71// Upper band of last band in the spectrum
72const qreal SpectrumHighFreq = 1000.0; // Hz
73
74// Waveform window size in microseconds
75const qint64 WaveformWindowDuration = 500 * 1000;
76
77// Length of waveform tiles in bytes
78// Ideally, these would match the QAudio*::bufferSize(), but that isn't
79// available until some time after QAudio*::start() has been called, and we
80// need this value in order to initialize the waveform display.
81// We therefore just choose a sensible value.
82const int WaveformTileLength = 4096;
83
84// Fudge factor used to calculate the spectrum bar heights
85const qreal SpectrumAnalyserMultiplier = 0.15;
86
87// Disable message timeout
88const int NullMessageTimeout = -1;
89
90
91//-----------------------------------------------------------------------------
92// Types and data structures
93//-----------------------------------------------------------------------------
94
95enum WindowFunction {
96 NoWindow,
97 HannWindow
98};
99
100const WindowFunction DefaultWindowFunction = HannWindow;
101
102struct Tone
103{
104 Tone(qreal freq = 0.0, qreal amp = 0.0)
105 : frequency(freq), amplitude(amp)
106 { }
107
108 // Start and end frequencies for swept tone generation
109 qreal frequency;
110
111 // Amplitude in range [0.0, 1.0]
112 qreal amplitude;
113};
114
115struct SweptTone
116{
117 SweptTone(qreal start = 0.0, qreal end = 0.0, qreal amp = 0.0)
118 : startFreq(start), endFreq(end), amplitude(amp)
119 { Q_ASSERT(end >= start); }
120
121 SweptTone(const Tone &tone)
122 : startFreq(tone.frequency), endFreq(tone.frequency), amplitude(tone.amplitude)
123 { }
124
125 // Start and end frequencies for swept tone generation
126 qreal startFreq;
127 qreal endFreq;
128
129 // Amplitude in range [0.0, 1.0]
130 qreal amplitude;
131};
132
133// Handle some dependencies between macros defined in the .pro file
134
135#ifdef DISABLE_WAVEFORM
136#undef SUPERIMPOSE_PROGRESS_ON_WAVEFORM
137#endif
138
139#endif // SPECTRUM_H
140
141

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