adamstark@46: //======================================================================= adamstark@46: /** @file BTrack.h adamstark@47: * @brief BTrack - a real-time beat tracker adamstark@46: * @author Adam Stark adamstark@46: * @copyright Copyright (C) 2008-2014 Queen Mary University of London adamstark@46: * adamstark@46: * This program is free software: you can redistribute it and/or modify adamstark@46: * it under the terms of the GNU General Public License as published by adamstark@46: * the Free Software Foundation, either version 3 of the License, or adamstark@46: * (at your option) any later version. adamstark@46: * adamstark@46: * This program is distributed in the hope that it will be useful, adamstark@46: * but WITHOUT ANY WARRANTY; without even the implied warranty of adamstark@46: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the adamstark@46: * GNU General Public License for more details. adamstark@46: * adamstark@46: * You should have received a copy of the GNU General Public License adamstark@46: * along with this program. If not, see . adamstark@46: */ adamstark@46: //======================================================================= adamstark@46: adamstark@46: #ifndef __BTRACK_H adamstark@46: #define __BTRACK_H adamstark@46: adamstark@55: #include "OnsetDetectionFunction.h" adamstark@55: adamstark@46: class BTrack { adamstark@46: adamstark@46: public: adamstark@51: adamstark@58: //======================================================================= adamstark@55: /** constructor assuming hop size of 512 and frame size of 1024 */ adamstark@56: BTrack(); adamstark@51: adamstark@55: /** constructor assuming frame size will be double hopSize adamstark@55: * @param hopSize the step size in audio samples by which we will receive audio frames adamstark@55: */ adamstark@57: BTrack(int hopSize_); adamstark@55: adamstark@55: /** constructor taking both hopSize and frameSize adamstark@55: * @param hopSize the step size in audio samples by which we will receive audio frames adamstark@55: * @param frameSize the audio frame size in audio samples adamstark@55: */ adamstark@57: BTrack(int hopSize_,int frameSize_); adamstark@55: adamstark@58: //======================================================================= adamstark@55: /** Process a single audio frame */ adamstark@56: void processAudioFrame(double *frame); adamstark@55: adamstark@55: /** Add new onset detection function sample to buffer and apply beat tracking */ adamstark@56: void processOnsetDetectionFunctionSample(double sample); adamstark@51: adamstark@58: //======================================================================= adamstark@57: /** @returns the current hop size being used by the beat tracker */ adamstark@57: int getHopSize(); adamstark@57: adamstark@58: /** @returns true if a beat should occur in the current audio frame */ adamstark@58: bool beatDueInCurrentFrame(); adamstark@58: adamstark@58: /** @returns the current tempo estimate being used by the beat tracker */ adamstark@58: double getCurrentTempoEstimate(); adamstark@58: adamstark@58: /** @returns the most recent value of the cumulative score function */ adamstark@58: double getLatestCumulativeScoreValue(); adamstark@58: adamstark@58: //======================================================================= adamstark@51: /** Set the tempo of the beat tracker */ adamstark@57: void setTempo(double tempo); adamstark@51: adamstark@51: /** fix tempo to roughly around some value */ adamstark@57: void fixTempo(double tempo); adamstark@51: adamstark@51: /** do not fix the tempo anymore */ adamstark@57: void doNotFixTempo(); adamstark@55: adamstark@58: //======================================================================= adamstark@55: static double getBeatTimeInSeconds(long frameNumber,int hopSize,int fs); adamstark@55: adamstark@55: static double getBeatTimeInSeconds(int frameNumber,int hopSize,int fs); adamstark@55: adamstark@58: adamstark@46: private: adamstark@51: adamstark@57: void initialise(int hopSize_,int frameSize_); adamstark@56: adamstark@56: /** Initialise with hop size and set all frame sizes accordingly */ adamstark@57: void setHopSize(int hopSize_); adamstark@56: adamstark@51: /** Convert detection function from N samples to 512 */ adamstark@57: void resampleOnsetDetectionFunction(); adamstark@51: adamstark@51: /** update the cumulative score */ adamstark@57: void updateCumulativeScore(double df_sample); adamstark@51: adamstark@51: /** predicts the next beat */ adamstark@57: void predictBeat(); adamstark@51: adamstark@51: /** Calculates the current tempo expressed as the beat period in detection function samples */ adamstark@57: void calculateTempo(); adamstark@51: adamstark@51: /** calculates an adaptive threshold which is used to remove low level energy from detection adamstark@51: * function and emphasise peaks adamstark@51: */ adamstark@57: void adaptiveThreshold(double *x,int N); adamstark@51: adamstark@51: /** calculates the mean of values in an array from index locations [start,end] */ adamstark@57: double calculateMeanOfArray(double *array,int start,int end); adamstark@51: adamstark@51: /** normalises a given array */ adamstark@57: void normaliseArray(double *array,int N); adamstark@51: adamstark@51: /** calculates the balanced autocorrelation of the smoothed detection function */ adamstark@57: void calculateBalancedACF(double *df_thresh); adamstark@51: adamstark@57: /** calculates the output of the comb filter bank */ adamstark@57: void calculateOutputOfCombFilterBank(); adamstark@46: adamstark@58: //======================================================================= adamstark@58: adamstark@58: OnsetDetectionFunction odf; adamstark@58: adamstark@58: //======================================================================= adamstark@46: // buffers adamstark@58: double *onsetDF; /**< to hold detection function */ adamstark@58: double resampledOnsetDF[512]; /**< to hold resampled detection function */ adamstark@58: double *cumulativeScore; /**< to hold cumulative score */ adamstark@46: adamstark@58: double acf[512]; /**< to hold autocorrelation function */ adamstark@46: adamstark@58: double weightingVector[128]; /**< to hold weighting vector */ adamstark@46: adamstark@58: double combFilterBankOutput[128]; /**< to hold comb filter output */ adamstark@58: double tempoObservationVector[41]; /**< to hold tempo version of comb filter output */ adamstark@46: adamstark@58: double delta[41]; /**< to hold final tempo candidate array */ adamstark@58: double prevDelta[41]; /**< previous delta */ adamstark@58: double prevDeltaFixed[41]; /**< fixed tempo version of previous delta */ adamstark@46: adamstark@58: double tempoTransitionMatrix[41][41]; /**< tempo transition matrix */ adamstark@46: adamstark@58: adamstark@46: adamstark@56: // parameters adamstark@56: double tightness; adamstark@56: double alpha; adamstark@57: double beatPeriod; adamstark@56: double tempo; adamstark@46: adamstark@58: double estimatedTempo; /**< the current tempo estimation being used by the algorithm */ adamstark@58: adamstark@58: double latestCumulativeScoreValue; /**< holds the latest value of the cumulative score function */ adamstark@58: adamstark@56: double p_fact; adamstark@46: adamstark@58: int m0; // indicates when the next point to predict the next beat is adamstark@58: adamstark@58: int beatCounter; /**< keeps track of when the next beat is - will be zero when the beat is due, and is set elsewhere in the algorithm to be positive once a beat prediction is made */ adamstark@46: adamstark@58: int hopSize; /**< the hop size being used by the algorithm */ adamstark@58: adamstark@58: int onsetDFBufferSize; /**< the onset detection function buffer size */ adamstark@46: adamstark@58: bool tempoFixed; /**< indicates whether the tempo should be fixed or not */ adamstark@57: adamstark@58: bool beatDueInFrame; /**< indicates whether a beat is due in the current frame */ adamstark@46: adamstark@46: }; adamstark@46: adamstark@46: #endif