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FIRFilter.h (4498B)

      1 ////////////////////////////////////////////////////////////////////////////////
      2 ///
      3 /// General FIR digital filter routines with MMX optimization. 
      4 ///
      5 /// Note : MMX optimized functions reside in a separate, platform-specific file, 
      6 /// e.g. 'mmx_win.cpp' or 'mmx_gcc.cpp'
      7 ///
      8 /// Author        : Copyright (c) Olli Parviainen
      9 /// Author e-mail : oparviai 'at' iki.fi
     10 /// SoundTouch WWW: http://www.surina.net/soundtouch
     11 ///
     12 ////////////////////////////////////////////////////////////////////////////////
     13 //
     14 // License :
     15 //
     16 //  SoundTouch audio processing library
     17 //  Copyright (c) Olli Parviainen
     18 //
     19 //  This library is free software; you can redistribute it and/or
     20 //  modify it under the terms of the GNU Lesser General Public
     21 //  License as published by the Free Software Foundation; either
     22 //  version 2.1 of the License, or (at your option) any later version.
     23 //
     24 //  This library is distributed in the hope that it will be useful,
     25 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
     26 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     27 //  Lesser General Public License for more details.
     28 //
     29 //  You should have received a copy of the GNU Lesser General Public
     30 //  License along with this library; if not, write to the Free Software
     31 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
     32 //
     33 ////////////////////////////////////////////////////////////////////////////////
     34 
     35 #ifndef FIRFilter_H
     36 #define FIRFilter_H
     37 
     38 #include <stddef.h>
     39 #include "STTypes.h"
     40 
     41 namespace soundtouch
     42 {
     43 
     44 class FIRFilter 
     45 {
     46 protected:
     47    // Number of FIR filter taps
     48    uint length;    
     49    // Number of FIR filter taps divided by 8
     50    uint lengthDiv8;
     51 
     52    // Result divider factor in 2^k format
     53    uint resultDivFactor;
     54 
     55    // Result divider value.
     56    SAMPLETYPE resultDivider;
     57 
     58    // Memory for filter coefficients
     59    SAMPLETYPE *filterCoeffs;
     60    SAMPLETYPE *filterCoeffsStereo;
     61 
     62    virtual uint evaluateFilterStereo(SAMPLETYPE *dest, 
     63                                      const SAMPLETYPE *src, 
     64                                      uint numSamples) const;
     65    virtual uint evaluateFilterMono(SAMPLETYPE *dest, 
     66                                    const SAMPLETYPE *src, 
     67                                    uint numSamples) const;
     68    virtual uint evaluateFilterMulti(SAMPLETYPE *dest, const SAMPLETYPE *src, uint numSamples, uint numChannels);
     69 
     70 public:
     71    FIRFilter();
     72    virtual ~FIRFilter();
     73 
     74    /// Operator 'new' is overloaded so that it automatically creates a suitable instance 
     75    /// depending on if we've a MMX-capable CPU available or not.
     76    static void * operator new(size_t s);
     77 
     78    static FIRFilter *newInstance();
     79 
     80    /// Applies the filter to the given sequence of samples. 
     81    /// Note : The amount of outputted samples is by value of 'filter_length' 
     82    /// smaller than the amount of input samples.
     83    ///
     84    /// \return Number of samples copied to 'dest'.
     85    uint evaluate(SAMPLETYPE *dest, 
     86                  const SAMPLETYPE *src, 
     87                  uint numSamples, 
     88                  uint numChannels);
     89 
     90    uint getLength() const;
     91 
     92    virtual void setCoefficients(const SAMPLETYPE *coeffs, 
     93                                 uint newLength, 
     94                                 uint uResultDivFactor);
     95 };
     96 
     97 
     98 // Optional subclasses that implement CPU-specific optimizations:
     99 
    100 #ifdef SOUNDTOUCH_ALLOW_MMX
    101 
    102 /// Class that implements MMX optimized functions exclusive for 16bit integer samples type.
    103    class FIRFilterMMX : public FIRFilter
    104    {
    105    protected:
    106        short *filterCoeffsUnalign;
    107        short *filterCoeffsAlign;
    108 
    109        virtual uint evaluateFilterStereo(short *dest, const short *src, uint numSamples) const;
    110    public:
    111        FIRFilterMMX();
    112        ~FIRFilterMMX();
    113 
    114        virtual void setCoefficients(const short *coeffs, uint newLength, uint uResultDivFactor);
    115    };
    116 
    117 #endif // SOUNDTOUCH_ALLOW_MMX
    118 
    119 
    120 #ifdef SOUNDTOUCH_ALLOW_SSE
    121    /// Class that implements SSE optimized functions exclusive for floating point samples type.
    122    class FIRFilterSSE : public FIRFilter
    123    {
    124    protected:
    125        float *filterCoeffsUnalign;
    126        float *filterCoeffsAlign;
    127 
    128        virtual uint evaluateFilterStereo(float *dest, const float *src, uint numSamples) const;
    129    public:
    130        FIRFilterSSE();
    131        ~FIRFilterSSE();
    132 
    133        virtual void setCoefficients(const float *coeffs, uint newLength, uint uResultDivFactor);
    134    };
    135 
    136 #endif // SOUNDTOUCH_ALLOW_SSE
    137 
    138 }
    139 
    140 #endif  // FIRFilter_H