spectrumanalyser.h Example File

multimedia/spectrum/app/spectrumanalyser.h
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#ifndef SPECTRUMANALYSER_H #define SPECTRUMANALYSER_H #include <QByteArray> #include <QObject> #include <QVector> #ifdef DUMP_SPECTRUMANALYSER #include <QDir> #include <QFile> #include <QTextStream> #endif #include "frequencyspectrum.h" #include "spectrum.h" #ifndef DISABLE_FFT #include "FFTRealFixLenParam.h" #endif QT_FORWARD_DECLARE_CLASS(QAudioFormat) QT_FORWARD_DECLARE_CLASS(QThread) class FFTRealWrapper; class SpectrumAnalyserThreadPrivate; /** * Implementation of the spectrum analysis which can be run in a * separate thread. */ class SpectrumAnalyserThread : public QObject { Q_OBJECT public: SpectrumAnalyserThread(QObject *parent); ~SpectrumAnalyserThread(); public slots: void setWindowFunction(WindowFunction type); void calculateSpectrum(const QByteArray &buffer, int inputFrequency, int bytesPerSample); signals: void calculationComplete(const FrequencySpectrum &spectrum); private: void calculateWindow(); private: #ifndef DISABLE_FFT FFTRealWrapper* m_fft; #endif const int m_numSamples; WindowFunction m_windowFunction; #ifdef DISABLE_FFT typedef qreal DataType; #else typedef FFTRealFixLenParam::DataType DataType; #endif QVector<DataType> m_window; QVector<DataType> m_input; QVector<DataType> m_output; FrequencySpectrum m_spectrum; #ifdef SPECTRUM_ANALYSER_SEPARATE_THREAD QThread* m_thread; #endif }; /** * Class which performs frequency spectrum analysis on a window of * audio samples, provided to it by the Engine. */ class SpectrumAnalyser : public QObject { Q_OBJECT public: SpectrumAnalyser(QObject *parent = 0); ~SpectrumAnalyser(); #ifdef DUMP_SPECTRUMANALYSER void setOutputPath(const QString &outputPath); #endif public: /* * Set the windowing function which is applied before calculating the FFT */ void setWindowFunction(WindowFunction type); /* * Calculate a frequency spectrum * * \param buffer Audio data * \param format Format of audio data * * Frequency spectrum is calculated asynchronously. The result is returned * via the spectrumChanged signal. * * An ongoing calculation can be cancelled by calling cancelCalculation(). * */ void calculate(const QByteArray &buffer, const QAudioFormat &format); /* * Check whether the object is ready to perform another calculation */ bool isReady() const; /* * Cancel an ongoing calculation * * Note that cancelling is asynchronous. */ void cancelCalculation(); signals: void spectrumChanged(const FrequencySpectrum &spectrum); private slots: void calculationComplete(const FrequencySpectrum &spectrum); private: void calculateWindow(); private: SpectrumAnalyserThread* m_thread; enum State { Idle, Busy, Cancelled }; State m_state; #ifdef DUMP_SPECTRUMANALYSER QDir m_outputDir; int m_count; QFile m_textFile; QTextStream m_textStream; #endif }; #endif // SPECTRUMANALYSER_H

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