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/*
* Copyright (c) 2001-2004 MUSIC TECHNOLOGY GROUP (MTG)
* UNIVERSITAT POMPEU FABRA
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef _OD_AudioDecimator_
#define _OD_AudioDecimator_
#include "Processing.hxx"
#include "Array.hxx"
namespace CLAM
{
namespace OnsetDetection
{
class AudioDecimatorConfig: public ProcessingConfig
{
public:
DYNAMIC_TYPE_USING_INTERFACE (AudioDecimatorConfig, 0, ProcessingConfig);
};
class AudioDecimator: public Processing
{
private:
bool ConcreteConfigure(const ProcessingConfig& cfg);
public:
const char * GetClassName() const {return "AudioDecimator";}
AudioDecimator();
AudioDecimator(AudioDecimatorConfig& c);
~AudioDecimator();
bool Do(void);
bool Do(DataArray &in, int sampleRate, int type);
// 44.1kHz to 22.05kHz decimation ( 2:1 ). Input signal
// is smoothed with a Tchebyshev filter to minimize
// aliasing. Filter coefficients were generated by
// MATLAB's cheby1 function with order=8, R=0.5 and wn=0.4
void DecimateFrom44100To22050( const DataArray& signal,
DataArray& decimatedSignal );
// 22.05kHz to 245 Hz decimation ( 90:1 ). Input signal
// is smoothed with a Tchebyshev filter to minimize
// aliasing. Due to the "extreme" decimation factor two
// filters are applied in sequence - one forward and the
// second one backwards - so to avoid phase distortion.
// Filter coefficients were generated by
// MATLAB's cheby1 function with order=4, R=0.5 and wn=1/90.
void DecimateFrom22050To245( const Array<double>& signal,
Array<double>& decimatedSignal );
void DecimateFrom22050To245( const Array<float>& signal,
Array<double>& decimatedSignal );
const ProcessingConfig &GetConfig() const { return mConfig;}
private: // attributes
AudioDecimatorConfig mConfig;
Array<double> mOutput;
Array<double> mOutputRev;
};
} // namespace OnsetDetection
} // namespace CLAM
#endif // _AudioDecimator_
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