/// <summary>
/// Calculate autocorrelation data and reflection coefficients.
/// Can be used to incrementaly compute coefficients for higher orders,
/// because it caches them.
/// </summary>
/// <param name="order">Maximum order</param>
/// <param name="samples">Samples pointer</param>
/// <param name="blocksize">Block size</param>
/// <param name="window">Window function</param>
public void GetReflection(int order, int *samples, int blocksize, float *window)
{
if (autocorr_order > order)
return;
fixed(double *reff = Reflection, autoc = autocorr_values, err = prediction_error)
{
Lpc.Compute_autocorr(samples, blocksize, autocorr_order, order, autoc, window);
Lpc.Compute_schur_reflection(autoc, (uint)order, reff, err);
autocorr_order = order + 1;
}
}
public void ComputeReflection(int order, double *autocorr)
{
fixed(double *reff = Reflection, autoc = autocorr_values, err = prediction_error)
{
for (int i = 0; i <= order; i++)
{
autoc[i] = autocorr[i];
}
Lpc.Compute_schur_reflection(autoc, (uint)order, reff, err);
autocorr_order = order + 1;
}
}
/// <summary>
/// Produces LPC coefficients from autocorrelation data.
/// </summary>
/// <param name="lpcs">LPC coefficients buffer (for all orders)</param>
public void ComputeLPC(float *lpcs)
{
fixed(double *reff = Reflection)
Lpc.Compute_lpc_coefs((uint)autocorr_order - 1, reff, lpcs);
}
