spectrum.h Example File

multimedia/spectrum/app/spectrum.h
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#ifndef SPECTRUM_H #define SPECTRUM_H #include <qglobal.h> #include "utils.h" #include "fftreal_wrapper.h" // For FFTLengthPowerOfTwo //----------------------------------------------------------------------------- // Constants //----------------------------------------------------------------------------- // Number of audio samples used to calculate the frequency spectrum const int SpectrumLengthSamples = PowerOfTwo<FFTLengthPowerOfTwo>::Result; // Number of bands in the frequency spectrum const int SpectrumNumBands = 10; // Lower bound of first band in the spectrum const qreal SpectrumLowFreq = 0.0; // Hz // Upper band of last band in the spectrum const qreal SpectrumHighFreq = 1000.0; // Hz // Waveform window size in microseconds const qint64 WaveformWindowDuration = 500 * 1000; // Length of waveform tiles in bytes // Ideally, these would match the QAudio*::bufferSize(), but that isn't // available until some time after QAudio*::start() has been called, and we // need this value in order to initialize the waveform display. // We therefore just choose a sensible value. const int WaveformTileLength = 4096; // Fudge factor used to calculate the spectrum bar heights const qreal SpectrumAnalyserMultiplier = 0.15; // Disable message timeout const int NullMessageTimeout = -1; //----------------------------------------------------------------------------- // Types and data structures //----------------------------------------------------------------------------- enum WindowFunction { NoWindow, HannWindow }; const WindowFunction DefaultWindowFunction = HannWindow; struct Tone { Tone(qreal freq = 0.0, qreal amp = 0.0) : frequency(freq), amplitude(amp) { } // Start and end frequencies for swept tone generation qreal frequency; // Amplitude in range [0.0, 1.0] qreal amplitude; }; struct SweptTone { SweptTone(qreal start = 0.0, qreal end = 0.0, qreal amp = 0.0) : startFreq(start), endFreq(end), amplitude(amp) { Q_ASSERT(end >= start); } SweptTone(const Tone &tone) : startFreq(tone.frequency), endFreq(tone.frequency), amplitude(tone.amplitude) { } // Start and end frequencies for swept tone generation qreal startFreq; qreal endFreq; // Amplitude in range [0.0, 1.0] qreal amplitude; }; //----------------------------------------------------------------------------- // Macros //----------------------------------------------------------------------------- // Macro which connects a signal to a slot, and which causes application to // abort if the connection fails. This is intended to catch programming errors // such as mis-typing a signal or slot name. It is necessary to write our own // macro to do this - the following idiom // Q_ASSERT(connect(source, signal, receiver, slot)); // will not work because Q_ASSERT compiles to a no-op in release builds. #define CHECKED_CONNECT(source, signal, receiver, slot) \ if (!connect(source, signal, receiver, slot)) \ qt_assert_x(Q_FUNC_INFO, "CHECKED_CONNECT failed", __FILE__, __LINE__); // Handle some dependencies between macros defined in the .pro file #ifdef DISABLE_WAVEFORM #undef SUPERIMPOSE_PROGRESS_ON_WAVEFORM #endif #endif // SPECTRUM_H