csvorbis.Lpc.lpc_from_data C# (CSharp) Method

        static float lpc_from_data(float[] data, float[] lpc,int n,int m)
        {
            float[] aut=new float[m+1];
            float error;
            int i,j;

            // autocorrelation, p+1 lag coefficients

            j=m+1;
            while(j--!=0)
            {
                float d=0.0F;
                for(i=j;i<n;i++)d+=data[i]*data[i-j];
                aut[j]=d;
            }

            // Generate lpc coefficients from autocorr values

            error=aut[0];
            /*
            if(error==0){
              for(int k=0; k<m; k++) lpc[k]=0.0f;
              return 0;
            }
            */

            for(i=0;i<m;i++)
            {
                float r=-aut[i+1];

                if(error==0)
                {
                    for(int k=0; k<m; k++) lpc[k]=0.0f;
                    return 0;
                }

                // Sum up this iteration's reflection coefficient; note that in
                // Vorbis we don't save it.  If anyone wants to recycle this code
                // and needs reflection coefficients, save the results of 'r' from
                // each iteration.

                for(j=0;j<i;j++)r-=lpc[j]*aut[i-j];
                r/=error;

                // Update LPC coefficients and total error

                lpc[i]=r;
                for(j=0;j<i/2;j++)
                {
                    float tmp=lpc[j];
                    lpc[j]+=r*lpc[i-1-j];
                    lpc[i-1-j]+=r*tmp;
                }
                if(i%2!=0)lpc[j]+=lpc[j]*r;

                error*=(float)(1.0-r*r);
            }

            // we need the error value to know how big an impulse to hit the
            // filter with later

            return error;
        }