Resample.h

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/**********************************************************************
 
   Audacity: A Digital Audio Editor
   Audacity(R) is copyright (c) 1999-2012 Audacity Team.
   License: GPL v2 or later.  See License.txt.
 
   Resample.cpp
   Dominic Mazzoni, Rob Sykes, Vaughan Johnson
 
**********************************************************************/
 
#ifndef __AUDACITY_RESAMPLE_H__
#define __AUDACITY_RESAMPLE_H__
 
#include "SampleFormat.h"
 
template< typename Enum > class EnumSetting;
 
struct soxr;
extern "C" void soxr_delete(soxr*);
struct soxr_deleter {
   void operator () (soxr *p) const { if (p) soxr_delete(p); }
};
using soxrHandle = std::unique_ptr<soxr, soxr_deleter>;
 
class MATH_API Resample final
{
 public:
   //
   // dMinFactor and dMaxFactor specify the range of factors for variable-rate resampling.
   // For constant-rate, pass the same value for both.
   Resample(const bool useBestMethod, const double dMinFactor, const double dMaxFactor);
   ~Resample();
 
   Resample( Resample&&) noexcept = default;
   Resample& operator=(Resample&&) noexcept = default;
 
   Resample(const Resample&) = delete;
   Resample& operator=(const Resample&) = delete;
 
   static EnumSetting< int > FastMethodSetting;
   static EnumSetting< int > BestMethodSetting;
 
   std::pair<size_t, size_t>
                Process(double       factor,
                        const float *inBuffer,
                        size_t       inBufferLen,
                        bool         lastFlag,
                        float       *outBuffer,
                        size_t       outBufferLen);
 
 protected:
   void SetMethod(const bool useBestMethod);
 
 protected:
   int   mMethod; // resampler-specific enum for resampling method
   soxrHandle mHandle; // constant-rate or variable-rate resampler (XOR per instance)
   bool mbWantConstRateResampling;
};
 
#endif // __AUDACITY_RESAMPLE_H__