G726.h

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/*
This program is distributed under the terms of the 'MIT license'. The text
of this licence follows...

Copyright (c) 2004 J.D.Medhurst (a.k.a. Tixy)

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#ifndef G726_H
#define G726_H

class G726
    {
public:
    enum Law{
        uLaw=0,     
        ALaw=1,     
        PCM16=2     
        };

    enum Rate{
        Rate16kBits=2,  
        Rate24kBits=3,  
        Rate32kBits=4,  
        Rate40kBits=5   
        };

    inline G726()
        {
        Reset();
        }

    void Reset();

    void SetLaw(Law law);

    void SetRate(Rate rate);

    unsigned Encode(unsigned pcm);

    unsigned Decode(unsigned adpcm);

    unsigned Encode(void* dst, int dstOffset, const void* src, size_t srcSize);

    unsigned Decode(void* dst, const void* src, int srcOffset, unsigned srcSize);
private:
    void InputPCMFormatConversionAndDifferenceSignalComputation(unsigned S,int SE,int& D);
    void AdaptiveQuantizer(int D,unsigned Y,unsigned& I);
    void InverseAdaptiveQuantizer(unsigned I,unsigned Y,unsigned& DQ);
    void QuantizerScaleFactorAdaptation1(unsigned AL,unsigned& Y);
    void QuantizerScaleFactorAdaptation2(unsigned I,unsigned Y);
    void AdaptationSpeedControl1(unsigned& AL);
    void AdaptationSpeedControl2(unsigned I,unsigned y,unsigned TDP,unsigned TR);
    void AdaptativePredictorAndReconstructedSignalCalculator1(int& SE,int& SEZ);
    void AdaptativePredictorAndReconstructedSignalCalculator2(unsigned DQ,unsigned TR,int SE,int SEZ,int& SR,int& A2P);
    void ToneAndTransitionDetector1(unsigned DQ,unsigned& TR);
    void ToneAndTransitionDetector2(int A2P,unsigned TR,unsigned& TDP);
    void OutputPCMFormatConversionAndSynchronousCodingAdjustment(int SR,int SE,unsigned Y,unsigned I,unsigned& SD);
    void DifferenceSignalComputation(int SL,int SE,int& D);
    void OutputLimiting(int SR,int& S0);
    unsigned EncodeDecode(unsigned input,bool encode);
private:
    Law LAW;
    Rate RATE;
    // Persistant state for DELAY elements...
    int A1;
    int A2;
    unsigned AP;
    int Bn[6];
    unsigned DML;
    unsigned DMS;
    unsigned DQn[6];
    int PK1;
    int PK2;
    unsigned SR1;
    unsigned SR2;
    unsigned TD;
    unsigned YL;
    unsigned YU;

    friend class G726Test;
    };

#define IMPLEMENT_G191_BUGS
 // End of group

#endif