SpectrumAnalyser.h

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#ifndef SPECTRUMANALYSER_H
#define SPECTRUMANALYSER_H

#include <QByteArray>
#include <QObject>
#include <QVector>
#include "FrequencySpectrum.h"
#include <windows.h>
#include "Utils.h"
#include "FFTRealFixLenParam.h"

QT_FORWARD_DECLARE_CLASS(QThread)

class FFTRealWrapper;

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 bitsPerSample,
                           int channels);

signals:
    void calculationComplete(const FrequencySpectrum &spectrum);

private:
    void calculateWindow();

private:

    FFTRealWrapper*                             m_fft;
    const int                                   m_numSamples;
    WindowFunction                              m_windowFunction;

    typedef FFTRealFixLenParam::DataType        DataType;
    QVector<DataType>                           m_window;

    QVector<DataType>                           m_input;
    QVector<DataType>                           m_output;

    FrequencySpectrum                           m_spectrum;
    QThread*                                    m_thread;
};


class SpectrumAnalyser : public QObject
{
    Q_OBJECT

public:
    SpectrumAnalyser(QObject *parent = 0);
    ~SpectrumAnalyser();

public:
    /*
     * 设置窗口函数
     */
    void setWindowFunction(WindowFunction type);

    /*
     * 计算频谱
     * 可以通过调用cancelCalculation()来取消正在进行的计算。
     */
    void calculate(const QByteArray &buffer, const WAVEFORMATEX &format);

    /*
     * 用于检验是否就绪（没有做其它运算）
     */
    bool isReady() const;


    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;
};

#endif // SPECTRUMANALYSER_H