annotate CepstrumPitchTracker.h @ 21:df41333abbc9 track

A first crack at turning frequencies into notes

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
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#ifndef _CEPSTRUM_PITCH_H_
#define _CEPSTRUM_PITCH_H_

#include <vamp-sdk/Plugin.h>

class CepstrumPitchTracker : public Vamp::Plugin
{
public:
    CepstrumPitchTracker(float inputSampleRate);
    virtual ~CepstrumPitchTracker();

    std::string getIdentifier() const;
    std::string getName() const;
    std::string getDescription() const;
    std::string getMaker() const;
    int getPluginVersion() const;
    std::string getCopyright() const;

    InputDomain getInputDomain() const;
    size_t getPreferredBlockSize() const;
    size_t getPreferredStepSize() const;
    size_t getMinChannelCount() const;
    size_t getMaxChannelCount() const;

    ParameterList getParameterDescriptors() const;
    float getParameter(std::string identifier) const;
    void setParameter(std::string identifier, float value);

    ProgramList getPrograms() const;
    std::string getCurrentProgram() const;
    void selectProgram(std::string name);

    OutputList getOutputDescriptors() const;

    bool initialise(size_t channels, size_t stepSize, size_t blockSize);
    void reset();

    FeatureSet process(const float *const *inputBuffers,
                       Vamp::RealTime timestamp);

    FeatureSet getRemainingFeatures();

protected:
    size_t m_channels;
    size_t m_stepSize;
    size_t m_blockSize;
    float m_fmin;
    float m_fmax;
    int m_vflen;

    int m_binFrom;
    int m_binTo;
    int m_bins; // count of "interesting" bins, those returned in m_cepOutput

    class Hypothesis {

    public:
        struct Estimate {
            double freq;
            Vamp::RealTime time;
            double confidence;
        };
        typedef std::vector<Estimate> Estimates;

        struct Note {
            double freq;
            Vamp::RealTime time;
            Vamp::RealTime duration;
        };
        
        Hypothesis();
        ~Hypothesis();

        enum State {
            New,
            Provisional,
            Satisfied,
            Rejected,
            Expired
        };

        bool test(Estimate);

        void advanceTime();

        State getState();

        int getPendingLength();
        Estimates getAcceptedEstimates();
        Note getAveragedNote();

        void addFeatures(FeatureSet &fs);

    private:
        bool isWithinTolerance(Estimate);
        bool isSatisfied();

        State m_state;
        Estimates m_pending;
        int m_age;
    };

    typedef std::vector<Hypothesis> Hypotheses;
    Hypotheses m_possible;
    Hypothesis m_accepted;

    void filter(const double *in, double *out);
    void fft(unsigned int n, bool inverse,
             double *ri, double *ii, double *ro, double *io);
};

#endif