c@116: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
c@116: /*
c@116:     Constant-Q library
c@116:     Copyright (c) 2013-2014 Queen Mary, University of London
c@116: 
c@116:     Permission is hereby granted, free of charge, to any person
c@116:     obtaining a copy of this software and associated documentation
c@116:     files (the "Software"), to deal in the Software without
c@116:     restriction, including without limitation the rights to use, copy,
c@116:     modify, merge, publish, distribute, sublicense, and/or sell copies
c@116:     of the Software, and to permit persons to whom the Software is
c@116:     furnished to do so, subject to the following conditions:
c@116: 
c@116:     The above copyright notice and this permission notice shall be
c@116:     included in all copies or substantial portions of the Software.
c@116: 
c@116:     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
c@116:     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
c@116:     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
c@116:     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
c@116:     CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
c@116:     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
c@116:     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
c@116: 
c@116:     Except as contained in this notice, the names of the Centre for
c@116:     Digital Music; Queen Mary, University of London; and Chris Cannam
c@116:     shall not be used in advertising or otherwise to promote the sale,
c@116:     use or other dealings in this Software without prior written
c@116:     authorization.
c@116: */
c@116: 
c@116: #ifndef CQINVERSE_H
c@116: #define CQINVERSE_H
c@116: 
c@116: #include "CQBase.h"
c@116: #include "CQKernel.h"
c@116: 
c@116: class Resampler;
c@116: class FFTReal;
c@116: 
c@147: /**
c@147:  * Calculate an inverse constant-Q transform. The input must be the
c@147:  * same representation as returned as output of a \ref ConstantQ
c@147:  * object with the same parameters. The output is a time-domain
c@147:  * signal.
c@147:  *
c@147:  * Note that you cannot perform an inverse transform from the
c@147:  * magnitude-only output of \ref CQSpectrogram; you need the complex
c@147:  * valued data from \ref ConstantQ.
c@147:  *
c@147:  * Our implementation of the Constant-Q transform is not exactly
c@147:  * invertible, and this produces only an approximation of the original
c@147:  * signal (see publications for details).
c@147:  */
c@116: class CQInverse : public CQBase
c@116: {
c@116: public:
c@147:     /**
c@147:      * Construct an inverse Constant-Q transform object using the
c@147:      * given transform parameters.
c@147:      */
c@127:     CQInverse(CQParameters params);
c@116:     virtual ~CQInverse();
c@116: 
c@147:     // CQBase methods, see CQBase.h for documentation
c@147:     virtual bool isValid() const { return m_kernel && m_kernel->isValid(); }
c@116:     virtual double getSampleRate() const { return m_sampleRate; }
c@116:     virtual int getBinsPerOctave() const { return m_binsPerOctave; }
c@116:     virtual int getOctaves() const { return m_octaves; }
c@116:     virtual int getTotalBins() const { return m_octaves * m_binsPerOctave; }
c@116:     virtual int getColumnHop() const { return m_p.fftHop / m_p.atomsPerFrame; }
c@116:     virtual int getLatency() const { return m_outputLatency; } 
c@116:     virtual double getMaxFrequency() const { return m_p.maxFrequency; }
c@116:     virtual double getMinFrequency() const; // actual min, not that passed to ctor
c@145:     virtual double getBinFrequency(double bin) const;
c@116: 
c@147:     /**
c@147:      * Given a series of constant-Q columns in the form produced by
c@147:      * the \ref ConstantQ class, return a series of time-domain
c@147:      * samples resulting from approximately inverting the constant-Q
c@147:      * transform.
c@147:      */
c@147:     RealSequence process(const ComplexBlock &);
c@116: 
c@147:     /**
c@147:      * Return the remaining time-domain samples following the end of
c@147:      * processing.
c@147:      */
c@116:     RealSequence getRemainingOutput();
c@116: 
c@116: private:
c@127:     const CQParameters m_inparams;
c@127:     const double m_sampleRate;
c@127:     const double m_maxFrequency;
c@127:     const double m_minFrequency;
c@127:     const int m_binsPerOctave;
c@127: 
c@116:     int m_octaves;
c@116:     CQKernel *m_kernel;
c@116:     CQKernel::Properties m_p;
c@116: 
c@116:     std::vector<Resampler *> m_upsamplers;
c@116:     std::vector<RealSequence> m_buffers;
c@116:     std::vector<RealSequence> m_olaBufs; // fixed-length, for overlap-add
c@116:     
c@116:     int m_outputLatency;
c@116: 
c@116:     FFTReal *m_fft;
c@116:     
c@116:     void initialise();
c@116:     void processOctave(int octave, const ComplexBlock &block);
c@116:     void processOctaveColumn(int octave, const ComplexColumn &column);
c@116:     void overlapAddAndResample(int octave, const RealSequence &);
c@116:     RealSequence drawFromBuffers();
c@116: };
c@116: 
c@116: #endif