firfilter.h

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/*****************************************************************************
 *
 * General FIR digital filter routines with MMX optimization. 
 *
 * Note : MMX optimized functions reside in a separate, platform-specific file, 
 * e.g. 'mmx_win.cpp' or 'mmx_gcc.cpp'
 * 
 * Author        : Copyright (c) Olli Parviainen
 * Author e-mail : oparviai @ iki.fi
 * File created  : 13-Jan-2002
 *
 * Last changed  : $Date: 2004/03/14 15:51:43 $
 * File revision : $Revision: 1.1.1.1 $
 *
 * $Id: FIRFilter.h,v 1.1.1.1 2004/03/14 15:51:43 mbrubeck Exp $
 *
 * License :
 * 
 *  SoundTouch sound processing library
 *  Copyright (c) Olli Parviainen
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *****************************************************************************/

#ifndef FIRFilter_H
#define FIRFilter_H

#include "STTypes.h"

class FIRFilter 
{
protected:
    // Number of FIR filter taps
    uint length;    
    // Number of FIR filter taps divided by 8
    uint lengthDiv8;

    // Result divider factor in 2^k format
    uint resultDivFactor;

    // Result divider value.
    soundtouch::SAMPLETYPE resultDivider;

    // Memory for filter coefficients
    soundtouch::SAMPLETYPE *filterCoeffs;

    virtual uint evaluateFilterStereo(soundtouch::SAMPLETYPE *dest, 
                                      const soundtouch::SAMPLETYPE *src, 
                                      uint numSamples) const;
    virtual uint evaluateFilterMono(soundtouch::SAMPLETYPE *dest, 
                                    const soundtouch::SAMPLETYPE *src, 
                                    uint numSamples) const;

public:
    FIRFilter();
    virtual ~FIRFilter();

    /// Operator 'new' is overloaded so that it automatically creates a suitable instance 
    /// depending on if we've a MMX-capable CPU available or not.
    void * operator new(size_t s);

    static FIRFilter *newInstance();

    /// Applies the filter to the given sequence of samples. 
    /// Note : The amount of outputted samples is by value of 'filter_length' 
    /// smaller than the amount of input samples.
    ///
    /// \return Number of samples copied to 'dest'.
    uint evaluate(soundtouch::SAMPLETYPE *dest, 
                  const soundtouch::SAMPLETYPE *src, 
                  uint numSamples, 
                  uint numChannels) const;

    uint getLength() const;

    virtual void setCoefficients(const soundtouch::SAMPLETYPE *coeffs, 
                                 uint newLength, 
                                 uint uResultDivFactor);
};


// Optional subclasses that implement CPU-specific optimizations:

#ifdef ALLOW_MMX

    /// Class that implements MMX optimized functions exclusive for 16bit integer samples type.
    class FIRFilterMMX : public FIRFilter
    {
    protected:
        short *filterCoeffsUnalign;
        short *filterCoeffsAlign;

        virtual uint evaluateFilterStereo(short *dest, const short *src, uint numSamples) const;
    public:
        FIRFilterMMX();
        ~FIRFilterMMX();

        virtual void setCoefficients(const short *coeffs, uint newLength, uint uResultDivFactor);
    };

#endif // ALLOW_MMX


#ifdef ALLOW_3DNOW

    /// Class that implements 3DNow! optimized functions exclusive for floating point samples type.
    class FIRFilter3DNow : public FIRFilter
    {
    protected:
        float *filterCoeffsUnalign;
        float *filterCoeffsAlign;

        virtual uint evaluateFilterStereo(float *dest, const float *src, uint numSamples) const;
    public:
        FIRFilter3DNow();
        ~FIRFilter3DNow();
        virtual void setCoefficients(const float *coeffs, uint newLength, uint uResultDivFactor);
    };

#endif  // ALLOW_3DNOW


#ifdef ALLOW_SSE
    /// Class that implements SSE optimized functions exclusive for floating point samples type.
    class FIRFilterSSE : public FIRFilter
    {
    protected:
        float *filterCoeffsUnalign;
		float *filterCoeffsAlign;

        virtual uint evaluateFilterStereo(float *dest, const float *src, uint numSamples) const;
    public:
        FIRFilterSSE();
        ~FIRFilterSSE();

        virtual void setCoefficients(const float *coeffs, uint newLength, uint uResultDivFactor);
    };

#endif // ALLOW_SSE

#endif  // FIRFilter_H