Chris@0: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@0: 
Chris@0: #ifndef RESAMPLER_H
Chris@0: #define RESAMPLER_H
Chris@0: 
Chris@0: #include <vector>
Chris@0: 
Chris@0: class Resampler
Chris@0: {
Chris@0: public:
Chris@0:     /**
Chris@0:      * Construct a Resampler to resample from sourceRate to
Chris@0:      * targetRate.
Chris@0:      */
Chris@0:     Resampler(int sourceRate, int targetRate);
Chris@0:     virtual ~Resampler();
Chris@0: 
Chris@0:     /**
Chris@0:      * Read n input samples from src and write resampled data to
Chris@0:      * dst. The return value is the number of samples written, which
Chris@0:      * will be no more than ceil((n * targetRate) / sourceRate). The
Chris@0:      * caller must ensure the dst buffer has enough space for the
Chris@0:      * samples returned.
Chris@0:      */
Chris@0:     int process(const double *src, double *dst, int n);
Chris@0: 
Chris@0:     /**
Chris@0:      * Return the number of samples of latency at the output due by
Chris@0:      * the filter. (That is, the output will be delayed by this number
Chris@0:      * of samples relative to the input.)
Chris@0:      */
Chris@0:     int getLatency() const { return m_latency; }
Chris@0: 
Chris@1:     /**
Chris@1:      * Carry out a one-off resample of a single block of n
Chris@1:      * samples. The output is latency-compensated.
Chris@1:      */
Chris@1:     static std::vector<double> resample
Chris@1:     (int sourceRate, int targetRate, const double *data, int n);
Chris@1: 
Chris@0: private:
Chris@0:     int m_sourceRate;
Chris@0:     int m_targetRate;
Chris@0:     int m_gcd;
Chris@0:     int m_filterLength;
Chris@0:     int m_bufferLength;
Chris@0:     int m_latency;
Chris@0:     
Chris@0:     struct Phase {
Chris@0:         int nextPhase;
Chris@0:         std::vector<double> filter;
Chris@0:         int drop;
Chris@0:         int take;
Chris@0:     };
Chris@0: 
Chris@0:     Phase *m_phaseData;
Chris@0:     int m_phase;
Chris@0:     double *m_buffer;
Chris@0: 
Chris@0:     void initialise();
Chris@0:     double reconstructOne(const double **);
Chris@0: };
Chris@0: 
Chris@0: #endif
Chris@0: